The Peter Attia Drive - Navigating bone health: early life influences and advanced strategies for improvement and injury prevention (#214 rebroadcast)

Episode Date: July 7, 2025

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter’s Weekly Newsletter In this episode from July 2022, Peter dives deep into the topic of bone health and explains why this is an important topic for everyone, from children to the elderly. He begins with an overview of bone mineral density, how it’s measured, how it changes over the course of life, and the variability between sexes largely due to changes in estrogen levels. From there he provides insights into ways that one can improve bone health, from exercise to nutrition supplements to drugs. Additionally, Peter discusses what happens when one may be forced to be sedentary (e.g., bedrest) and how you can work to minimize the damage during these periods. While this original episode is an AMA, it is available in full to all listeners as a special rebroadcast. We discuss: Overview of bone health topics to be discussed [2:30]; Bones 101: bone function, structure, and more [6:15]; Bone mineral density (BMD), minerals in bone, role of osteoblasts and osteoclasts, and more [9:30]; The consequences of poor bone health [14:30]; The devastating nature of hip fractures: morbidity and mortality data [18:00]; Where fractures tend to occur in the body [23:45]; Defining osteopenia and osteoporosis [25:30]; Measuring BMD with DEXA and how to interpret scores [28:00]; Variability in BMD between sexes [35:15]; When should people have their first bone mineral density scan? [37:45]; How BMD changes throughout the life and how it differs between men and women [40:15]; How changes in estrogen levels (e.g., menopause) impact bone health [45:15]; Why HRT is not considered a standard of care for postmenopausal bone loss [49:00]; Factors determining who may be at higher risk of poor bone health [52:00]; Common drugs that can negatively impact BMD [55:45]; How children can optimize bone health and lay the foundation for the future [59:30]; Types of physical activity that can positively impact bone health [1:03:30]; How weight loss can negatively impact bone health and how exercise can counteract those effects [1:12:15]; Nutrition and supplements for bone health [1:16:00]; Pharmaceutical drugs prescribed for those with low BMD [1:18:45]; Impact of extreme sedentary periods (e.g., bedrest) and how to minimize their damage to bone [1:23:30]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

Hey everyone, welcome to the Drive Podcast. I'm your host, Peter Attia. This podcast, my website, and my weekly newsletter all focus on the goal of translating the science of longevity into something accessible for everyone. Our goal is to provide the best content in health and wellness, and we've established a great team of analysts to make this happen. It is extremely important to me to provide all of this content without relying on paid ads. To do this, our work is made entirely possible by our members, and in return, we offer exclusive member-only content and benefits above and beyond what is available for free.

If you want to take your knowledge of this space to the next level, it's our goal to ensure members get back much more than the price of a subscription. If you want to learn more about the benefits of our premium membership, head over to PeterAtiyaMD.com forward slash subscribe. Welcome to a special episode of The Drive. This week we are rebroadcasting our in-depth AMA, which was AMA 37 on bone health. It was released to subscribers initially, but we're opening this one up to everybody so that those of you who are not subscribers might get a sense of what the AMAs are all about. In this episode, we discuss why fracture related death rises steeply after the age of 65,

especially following hip and pelvic breaks, and why prevention must start decades earlier, what bone mineral density is, and how DEXA scans measure it, and how to read a T score and Z score, how bone changes with age in men and women, the outsize effects of menopause and estrogen loss, and the role of vitamin D, calcium, parathyroid hormone,

and magnesium in bone turnover, the difference between healthy bone, osteopenia, and osteoporosis, and when each diagnosis is made, major risk factors for low BMD, when to start screening, sooner than most guidelines suggest, and how often to repeat DEXA, which type of exercises best improve or preserve BMD, nutritional priorities for bone, how weight loss without resistance training accelerates

bone loss and why combining diet with heavy load exercise can offset it, pharmacologic options when lifestyle options are not enough, and strategies to minimize bone loss during bed rest or injury. So without further delay, I hope you enjoy this rebroadcast of the Bone Health AMA. Hey! Hey! Hey!

Hey! Hey! Hey! Hey! All right, Peter, welcome to another AMA. How you doing? Doing well, man. The final seven episodes of Ozark dropped tonight.

We're recording this April 29th. Interesting date for two reasons, by the way. The other thing that occurred to me this morning is that the days and dates in this year, 2022, were the same as they were in 1994. So, I was like, oh my God, today is Friday, April 29th, which is the same as it was in 1994. So, on Friday, April 29th in 1994 was the practice day at Imela. And that's when Rubens Baricella had that horrible, horrible accident.

We can link to the accident where he basically hit the chicane and launched into a barrier and amazingly only escaped with a concussion and a broken nose. The following day, which is the same day as tomorrow will be, which was Saturday, April 30th, was when Roland Ratzenberger was killed, which made it the first fatality in Formula One in 12 years, the last one being Gilles Villeneuve in 1982. And then of course, Sunday, May 1st, which will be the same this year was when Senna died. All in 1994. Yeah, I was at the same race. You had these three horrible accidents resulting in two

fatalities in one weekend. But again, to think it's the exact same days this year as it was 28 years ago. I didn't notice that until today. This is really off topic, but do you still have the skill that you had back in the day where you can remember what day, like day of the week a date was? Only if I can peg it to something, but not as profound as it used to be. I remember in meetings, we used to just throw out random dates and then we would fact check it and feel like we wasted a lot of time doing that. Someone would tell me their birthday and I would tell them what day of the week

they were born on. On the complete opposite end of that, what we're going to talk about today is the topic that we get asked about a lot. And we've gotten a lot of questions that have come in, but we've never really dove really deep into it, which is what we're going to do today. And it's kind of all things, bone health, bone mineral density, osteopenia, osteoporosis, things of that nature. And I know this is something that you work a lot with in your patients.

And I know it's something that's of really big interest for people. And so our hope is that we can go through this episode and focus on why is this important? So why should people care about this? People listening right now, there'll be a subsection of them that are going to be super interested and there will be probably another subsection who are maybe younger, they've never really thought about their bone health and they might not think it really applies to them. But our hope is in the beginning at least, we'll walk through why they should care about

this and why they should focus on it early on in life. And then from there, we'll talk about how bone health changes as people age, the differences between sexism in men and women. And then we'll also focus on things on how people can improve or help their bone health become better from physical activity to nutrition, supplements, drugs, and more.

And then if all that goes well and we still have time, which is always 50-50 on how these AMAs go, we'll also focus a little bit on people dealing with acute injuries and how they need to think about this, which I know is something that you're interested in, given your recent shoulder surgery, and now you're not as active in one side of your upper body as you used to be.

All that said, I think before we start going through those questions, it's going to be helpful to set the stage a little bit just so everyone is on the same page and the definitions and what we're talking about. So why don't we start with what are some of the types of bones we'll be referring to? Because at least for myself coming into this, I just kind of think of bone as a bone and I don't really think much more beyond that. So why don't you dive into that a little bit. Bone is, it's a living tissue.

Okay, that's obvious, but I think it's also easy for a person to forget that and think of bone as somewhat inert. But in fact, bone is heavily vascularized. Bone is an organ that plays a very important role in a lot of things. I'm actually not going to go super deep into the anatomy and physiology of bones. I'll point out just a couple of things, right? First of all, think of a couple types of sections of bone. We think about the cortical or compact bone and that's what forms like the shaft in the exterior of long bones. If you think of your femur, your humerus, things like that,

they have the long shaft and then the nubbins at the end. The shaft of that is the cortical or compact bone. At the end, you have the trabecular bone, sometimes called the spongy bone. Those are at the end of the bone. There are some differences amongst those in terms of their vascularization and things like that. Again, I think for the purpose of this discussion, whenever I talk about compact or cortical bone, I'm talking about the shaft. Whenever I speak about the spongy or trabecular part, I'm talking about the end. Again, I think marrow, people probably intuitively understand that marrow is important, but again, it's very important. Marrow is what's producing our white cells and our red blood cells. In this era where we were thinking about a post-COVID world, it's important to understand that the memory B cells and memory T cells that are going

to provide lasting immunity against this virus and other viruses reside in the bone marrow. The whole purpose of being infected and then having a subsequent infection that's less devastating, purpose of being vaccinated for the same reason, is to have memory B cells and T cells that are sitting there in the bone marrow that can respond immediately and quickly upon reintroduction of the same antigen. When you mentioned nubbins, it made me think about your banana nubbins. You recently posted on Twitter, you might be looking for a new profession. Do you want to let people know what your new interest is in the world of longevity? I've been very interested in human longevity

for a little over 10 years, and I'm sure I will remain so, but I've at least considered moving into banana longevity because I think the opportunity for impact is huge. It's one thing if you can figure out how to take the average person from being 80 to 90, that'll have a huge impact on the world. But if you could take the average banana and go from like two days before it turns mushy and brown to 10 days, I think it's revolutionary. I just noticed I was on the USDA's most wanted list because of how many bananas I waste. So I got to do something about this. If you solve the banana crisis and you move to avocados,

they'll probably give you a Nobel Peace Prize as well. The upside is very high in this new world. Avocados last so much longer. I could buy like seven avocados and eat them in a week. I can't buy seven bananas and eat them in a week. At one a day, it just doesn't work. I think that entire fruit space is just a racket. I think bananas are a pyramid scheme.

The whole thing is just total scam. Maybe one of our upcoming AMAs will just do a conspiracies with Peter Atiyah and we'll just go into the world of bananas. So Peter, you mentioned earlier ago, B cells and T cells. Can you walk people through what cells make bones? This can be made as complicated or as simple as you want. Just think about osteoblasts and osteoclasts. I kind of remember from medical school the way I used to remember

this. Osteoblasts B are responsible for building bone by producing collagen bone matrix and mineralizing it. Osteoclasts remove bone by reabsorbing calcified bone and the matrix. So osteoblasts contribute to increasing bone mineral density, osteoclasts the opposite. It's also important to understand this exists in an equilibrium. So we're constantly remodeling bone, adding to and subtracting from this and basically turning over calcium. Bone is like 50 to 70% mineral and obviously what's the predominant mineral? It's calcium. We'll talk about that in a second. It's about 20 to 40% organic matrix. Again, what does organic mean? Organic is carbon,

hydrogen, oxygen, sulfur, etc. Then the rest of it is a bit of water and lipid. Again, you'll see that primarily in marrow. In an adult, the entire human skeletal system can be remodeled in a really long cycle. It might take 10 years to turn over all of the mineral and organic content within the bone over and over again. At the micro level, calcium balance is happening quite frequently. I don't remember the exact number. I want to say it's like 99%, but virtually all of the body's calcium is contained within bone. Therefore, bone plays a very important role in calcium homeostasis.

If anybody's taken a physiology class, they probably remember how important calcium signaling is to everything within a cell. Again, we think of these bones as structural entities, which of course, first and foremost, they are. But remember, they're also a very important reservoir for calcium, which is another very important ion in the activity of a resell. You talked a lot about calcium.

What about vitamin D? What role does vitamin D play in the bones? They're both very important. And again, there's two forms of vitamin D, vitamin D2 and D3. But really when I talk about vitamin D, I'm going to mostly talk about D3, which is the active form. So what's the problem with being deficient in vitamin D? Well, again, people might recall a disease called rickets. You see this often in developing parts of the world where people are really malnourished and they have really, really soft sort of spongy bone. Actually, just yesterday, I had a friend over who

does a bunch of mission work in Rwanda and she was showing me a child at their camp whose legs, the child was like probably five years old. He was sitting down and they were doing something with his legs that you would think would be impossible to do with a human being. Basically, while he was sitting on the ground, they were able to move his foot back and forth, back and forth. He was in no pain, but it's because he didn't have bones that were anything other than basically rubber bands. He couldn't stand. or anything other than basically rubber bands. He couldn't stand. Within, I want to say, six months of correcting his nutrition, totally normal. Amazing opportunity when you think about what happens in that part of the world and how you can fix that. What is it about vitamin D?

Well, vitamin D increases the gut's absorption of calcium. If you're woefully deficient in vitamin D, you're going to have trouble absorbing calcium through the gut. We're going to talk in this podcast later about the importance of dietary calcium and or supplementary calcium. You can see why that becomes part of the issue. The other thing to keep in mind here is the role of another hormone. Again, I'm trying to only introduce concepts now that are going to become relevant later, either through treatments or nutrition or supplementation. So I'm being a little bit simplistic, but the other thing that you can't avoid here is understanding the role of calcium

and parathyroid hormone. I think most people are probably familiar with their thyroid gland sits here in the neck. It's kind of got this shape to it where it's got like two main lobes, and then each lobe has two poles. Well, at each of those poles is a little tiny gland called the parathyroid gland. So you have four of those.

And the parathyroid gland is really the master gland for regulating calcium levels. So low levels of calcium in the blood stimulate parathyroid hormone secretion. As parathyroid hormone level goes up, it simulates the release of calcium from the bone into the blood. Now, it also induces enzymes in the kidney which then convert vitamin D into its active form to then aid and speed up in the process of reabsorbing more calcium from the diet. All of this stuff, parathyroid hormone, calcium, vitamin D, very important to maintaining bone health.

And anytime you have things that disrupt that system, you're going to see disruptions potentially in the bones. And I think that was a good quick overview of what will be important for what we cover next. And I think the natural follow-up to it is what is the consequence of poor bone health? What is the consequence of low bone density? Some people who will be listening to this will have already known issues of bone density,

and some people have never thought about this before in their life. What would you say to those people on why they should care about this and why they should think about it? This is one of those things that I would say five years ago I was not paying nearly as much attention to as I am today. I think the

easiest way to show this is put a couple of figures together. Can you pull up figure one, Nick? This is a figure that we made. It's an internal analysis. It's a very straightforward analysis. All we've done is taken data from the CDC database from 2019. The reason we use 2019 is by the time you get to 2020, you start to get some COVID data mixed in there. Although the accidental stuff only changes in that you see a higher rate of overdose. You're looking at the absolute number of deaths by decade for people aged 25 to 35 all the way up to 85 and up.

We basically break accidental deaths into four categories. Overdoses, transportation accidents, which are mostly car accidents, falls, and everything else. As you can see, those first three, accidental overdose, transport deaths, and falls represent virtually all accidental deaths. So you can almost ignore everything else. This is the absolute numbers. These are total numbers. And two things stand out here really clearly. The first is that for people younger than 60, overdoses are the predominant cause of accidental death. For people over 65, falling is. If you go to the next figure, it tells

I think a more important story, which is when you adjust for the population. Because remember, in figure one, what I'm showing you is total number of deaths. But what you don't realize is that as you move left to right, the denominator, the population is getting smaller and smaller and smaller. There are fewer and fewer people in each bucket as you go to the right. So to correct for that, we would ask the question, which is how many of these deaths per 100,000 people occur in each group.

If you look at that figure, I think the story is readily apparent, which is that by the time you're 75, the risk of death from a fall is enormous. Now, it's not as high as Alzheimer's disease, it's not as high as cancer, and it's not as high as heart disease, But it comes in pretty much just after that. This is what sets the stage because on the one hand, I think you can look at these data and say, wow, this is really problematic. But the other point is you can't wait until you're in that bucket to decide you're going to do something about it. So just as for atherosclerosis, we don't want to wait until we've had our first heart attack,

I really need to worry about my APOB and maybe I should stop smoking and make sure my blood pressure is okay. You don't want to wait until you have osteopenia or osteoporosis and you're 60 years old to say, it's time to do something about this. Now, if you're there, there's lots to do about it. But it's just as important if you're 25 years old, and frankly, it's just as important as a parent if you're thinking about what your five-year-old and 10-year-old and 15-year-old should be doing to make sure that they're setting themselves up for the best outcomes possible as they age, of course. Let's look at figure three now. So, what you're looking at here is the excess mortality for women, which is shown on the top, men, which is shown on the bottom,

following a hip fracture. This is going to come up over and over again. We're going to get into some data about what are the fractures that really end lives. You're going to see it's primarily hip fractures. Pelvic fracture, I think, is probably second. In part, this results from the immobility that comes after it. I think there are some other reasons at, this results from the immobility that comes after it, but I think there are some other reasons at play there. What we're looking at here in the top graph is women following a hip fracture, men following a hip fracture, and you're looking at mortality as a function of age. This is kind of staggering. When I first saw this, I couldn't believe it. I apologize for people who are only listening to this podcast.

Again, this is one of those podcasts where I think it really helps to be able to see the figures. I'll do my best to explain what the figures show. For those who are looking at it, I don't think you need me to say anything. You can just plug your ears and go, la, la, la, la, la, la, la, as I explain this because there's nothing I need to say if you can read this graph. If you're 90 years old or above and you're a man and you have a hip fracture in this data set, and we're going to talk about other data sets in a moment, more than 40% of you will be dead within a year. Now that mortality comes down.

That's generally the case. The mortality tends to come down because there's kind of a survival benefit or there's fewer people in that group. What's the mortality of people who are 90 over the next 10 years? That number is going down because most of them have already died. You can see for the younger demographics, the numbers go up. The good news is in this cohort at least, if you're 70 years old and you break your hip, 10% of those people are going to be dead in three years, but that number just keeps going up and up and up. The important thing here from this data set, because we're going to look at another one

in a second that I think is more stark. In this data set, what you realize is that for older people, people over the age of 85, people over the age of 80, I think most of us listening to this podcast, if we're not that age, certainly have aspirations to be that age. Your mortality is in the neighborhood of a third within a year after a hip fracture. Nick, we're going to have Michael Easter on the podcast coming up soon, aren't we? Yeah, that will come out mid-summer probably. For those who aren't familiar with Michael's work, he wrote a book called The Comfort Crisis, which I'm going to say is

probably one of the 10 books that I'll sort of force down most people's throats if given the chance. I think it's a really important book. A topic from that book will actually come up later in this episode, Nick, when we start to talk about exercise and what we can do to reduce the loss of bone mineral density as we age. But in the book, he makes some references to a few studies that I went back and looked at that talk about some of the unbelievable high mortalities in other fractions. If you look at another study, the study had about 200 people in it.

It looked at the six-month mortality in people who were 65 or older who fractured their hip and the mortality was 25%. Again, I want to repeat what the implication of that is. If you look at a group of people who are 65 years old or older who fracture their hip falling, 25% of those people will be dead in six months. Now, obviously, when you include younger people, that mortality goes way down. So if they lowered the threshold in that study to people 50 and older, that mortality came down to just under 14%. Another study, which was a finished study that looked at a little over 400 consecutive hip fractures in patients, found that the one-year post-operative mortality was just over 27%.

So again, totally different patient population and by the way, different country, very similar trend. And I think perhaps the most rigorous of these studies was a large study that looked at about 122,000 participants who were at least 60 years old from various cohorts, so Europe, the US, etc. Followed them for 12 or 13 years on average and during that time found 4,200 hip fractures. This study was able to then compare total mortality and look at the hazard ratio in the first year following the hip fracture. So, now this is asking the question, what is the probability or what is the increased risk of death one year following the hip fracture in this patient population? Again, these are people enrolled at the age of 60 or beyond.

And the hazard ratio is 2.78. So, again, what does that mean? 2.78 means a 178% increase in the risk of mortality within one year following a hip fracture. There are lots of studies like this. I don't think we need to spend the rest of the AMA on it. I think regardless of how you slice and dice these data, a hip fracture is a devastating outcome and it's something that we really want to avoid at any age, but especially when we're into our seventh decade and beyond. Just for reference, what's the hazard ratio for smoking again?

The hazard ratio for smoking on all-cause mortality is less than 2.78 for sure, because the hazard ratio for end-stage renal disease is about 2.76 for all cause mortality. Smoking is probably just below two. So great point, Nick. This has a greater mortality than smoking. The other really interesting thing when you look at those two graphs is I would love to

do a study on the people who are over 90 when they fractured their hip and survived at 10 years. You know, who are those people in their hundreds just like kicking it around, still going strong. It'd be really interesting to see. Do we know where fractures occur in the body? If you pull up this figure, Nick, I think this is a really elegant way to look at this. You're looking at all the sites of fractures and in the first column, it's showing you how many fractures occurred in this study, but it's ranking it by median age. So, I've just highlighted the first one, which is proximal femur, which is hip fractures. Not only are those highly frequent, 4,000 fractures, but look at the median age, 81.1. Pelvis right there, 73.2 behind it. Neck of the femur, 70. Distal femur, 70. Acetabulum,

which is the cup that holds the femoral head, 68. And then down to say proximal humerus, so the top of the humeral bone 66. So those are the big fractures for people over the age of 65. Again, you can see that frequency of proximal humerus and proximal femur are very high. You can go through this list and it's really telling about how people fall. What's a distal radius fracture? The fracture at the end of your hand. So the radius bone runs right here, just so you can see. How does someone break that, right? They break that by falling. You sort of get a sense of how balance, strength

impact a lot of these things. Yeah, out of curiosity, what's the talus? What's the last thing on the list? Foot. Foot. Foot. Yeah. So the next terminology that I think would be important for people to know, cause we do get a lot of questions on it. We're going to talk a lot about it is the terms osteopenia, osteoporosis,

just for people who don't know myself included, are they the same? Do they mean the same? How do we think about them different? Why is it important to differentiate between them? So just think of this as a continuum, Nick. And in fact, if you pull up figure four, this is not entirely helpful, but at least schematically helpful figure. On the left of this figure, you see you've got kind of like the healthy bone. See how it's got that little inlet beneath it? That's kind of showing you like the density of the calcified mineral that makes up the strong part of the bone.

Osteopenia and osteoporosis just exist on a continuum relative to healthy bone. Now this is going to get a little complicated and I'll explain it in the amount of rigor that's necessary in a moment, but let's just start with the concept. When you go from healthy bone to osteopenia, that represents about a 10% reduction in bone mineral density relative to a young healthy adult. Then osteoporosis is a further degradation where you hit about 25% reduction. Now there are two things that I have to add to this to make it sort of rigorous. The first is the diagnosis of osteopenia and osteoporosis is based on two locations, technically three,

but two of them are symmetric, the hips and the lumbar spine. So for anybody who's gone and had a DEXA scan before, you may notice that they report the Z score and T score, which I'll explain in a second, of the lumbar spine, of the left hip, the right hip, and usually of the entire body. The reason for that is we use left hip, right hip, lumbar spine, L1 to L5 to make this diagnosis. Those are the areas we look at. I assume the reason for that is that's where the fractures are. We see people that have atraumatic fractures, compression fractures in the lumbar spine. As you're going to see in a moment, the majority of fractures in older people are in the hip. And as I just shared a moment ago, the mortality for those fractures is very high. So that's where

the diagnosis is made. So again, osteopenia, 10% reduction in BMD, osteoporosis, 25% reduction in BMD. And again, these are made to healthy individuals. Healthy bone to osteopenia to osteoporosis, it's just a continuum. But osteoporosis and osteopenia are distinct in the degrees to which BMD has been reduced. And Peter, you mentioned DEXA there a little bit ago, and anyone who's listening to this podcast

will be familiar with the DEXA scan because we talk about it a lot and looking at fat and the benefits that you can get from that. Is that the best way for listeners to figure out what their BMD is? Is that how you're doing it in patients? Yes. So Dexa is a super, super low radiation scan, nothing like a CT scan. It takes 10 minutes. You lay on a table, a little scanner moves over your body, and it's using two very low dose x-rays that are absorbed differentially by bones and soft tissues. So, it's able to

differentiate between adipose tissue, bone, and lean tissue or non adipose tissue. I will say this, not all DEXA scanners are created equal. So if you want to know your bone health, make sure before you go and get the DEXA scan, you confirm with the entity doing this, that they are giving you segmental bone analysis for left hip, right hip, lumbar spine. A lot of Dexa places can only give you whole body BMD. So they'll just spit out the Z score for that one metric, but they won't give it to you segmentally. And that's sometimes okay.

If a person's BMD is very high, you don't need the segmental analysis. But if you're doing this to screen for BMD, you have to make sure of course that the DEXA is capable of doing that. And just a reminder for people, we talked about this in another episode, but we were always surprised at how easy it is to get a DEXA scan, right? You don't need a doctor to do it. So if you just Google the city you're in and then DEXA, you should be able to find different providers that do it for relatively cheap. I think in most cities, it's around $100, $150. So it has a lot of benefits. And just maybe remind people again, if they are calling different places,

what are the three things they want to look for? You want to make sure when you're doing a DEXA, again, if you care about knowing the full BMD, you're going to pay more for that segmental analysis. So when you talk about those scans that are like in the 100, 125, even up to 150, a lot of times they aren't showing everything. They're just giving you body composition and usually visceral fat. Now, you'll say up to $400 typically if you want to see everything.

But again, you're going to pay more in New York and San Francisco than you're going to pay in Austin, Texas for example. I probably pay like 125 for mine, but I'm not getting the full BMD analysis because I've already had it done and my BMD is high. I don't need to screen that frequently, not at the rate that I screen everything. The other things you want to look at, you obviously want to make sure you're getting full segmental lean tissue analysis. You can look at Appendicular Lean Mass Index that you can calculate for yourself. Obviously,, fat free mass index you can calculate for yourself. Fat mass index you can calculate. You need them to be able to give you that. Those are the things I want to see along with BMD. Let's say you and a friend are going and getting your BMD done through a nexus scan,

is there going to be variability that exists in bone density between different people? Let's say even if someone didn't have osteopenia or osteoporosis, can there just be natural variability between different types of people? Yeah, and it's also important to understand the number you're going to get. They don't, at least to my knowledge, I don't recall seeing them typically report

in grams per centimeter cubed your BMD. Because what would you do with that information? It's not that helpful. What you really need to know is statistically where do you rank? And this is done via a T score and a Z score. And this is done to compare you to a young healthy adult and to an adult that is your age. If you go back to Statistics 101,

I think many people may recall the idea of a normal distribution, which is a bell curve function. A z score is basically telling you where you lie on that distribution. A Z score of zero means you are right in the middle of the distribution. If you are in the middle of that distribution, it means you have a higher bone mineral density than 50% of people and a lower bone density than 50% of people. If your Z score is plus one, it means you are one standard deviation above the mean, which means you have a higher bone density than 82.5% of the population and a lower bone density than 17.5% of the population. If your Z score is plus 0.2, it means you are two standard deviations above the mean. You're higher than 97.5% of the population. Of course, this works in reverse. A Z score of minus two means you have a lower

bone density than 97.5% of the population. So that's what Z scores do. I'm sorry, I may have misspoke. The Z score is comparing you to your age when I say the population. The T-score is comparing you to the young, healthy individual. So in other words, for someone who's older, the Z-score is always going to be more favorable than the T-score.

Does that make sense? If you're 60, you wanna compare yourself to not only a 30-year-old, but also other 60-year-olds. That's correct. When you look at for yourself and even with your patients, their scores, is it kind of like how you do VO2 max where you always want to be in the elite of the elite categories? You know, VO2 max, you want to be elite and a decade younger. For BMD, if someone is at that zero, that 50th percentile, does that

worry you or is it a little different in how you look at this? Other things factor into this, Nick. Family history factors into it. History of smoking factors into this. Current lifestyle, I hate the word lifestyle, but I think you know what I mean. How active is that person? How much weight-bearing activity are they doing? Being male versus female also factors into it a lot. If I see a woman prior to menopause, let's say I got a 42-year-old female patient who's I might guess three to five years out from menopause and she already has a low Z score, that worries me a lot because of what we'll talk about shortly, vis-a-vis the effect of estrogen here and why women are disproportionately affected by estrogen withdrawal.

You've heard me make this glib, stupid joke, right? Never in the history of civilization has a 90-year-old person ever been heard uttering, I wish I was less strong. I wish I had less muscle. I wish my bone density wasn't so high. Right? Impossible. You know how Tim Ferriss always asked people on the podcast, well, but they put on a billboard? We've come to the conclusion of what you would 100% put on your billboard. That's right. The Peter Atiyah billboard would just say, find me one example in the history

of our species where a 90-year-old said, I wish I had less strength, I wish I had less muscle, I wish I had weaker bones. So, Nick, before we leave this point, let's just pull up figure five and show some of the sex differences and race differences. Yep. Got it pulled up. Okay. So, you can see on this graph, we're looking at males versus females, top to bottom.

And then we're looking at Mexican American, non-Hispanic white, non-Hispanic black. So three races, two sexes, six lines. But I just want to make one thing to the listener a little bit clear, which is on the y-axis here, you're seeing units of grams per centimeter squared. Earlier I said grams per centimeter cubed. Why the difference? Well, the difference is even though density in real life is measured in grams per centimeter cubed because you need mass per unit volume, with bone density, it's actually done as grams per centimeter squared because it's a planar measurement. So the DEXA scan is compressing everything to 2D. Does that make sense? Because the scanner is kind of looking at the area of the bone and imputing the density

by what electron beam doesn't go through it. I've always found this a bit confusing personally. I've always wondered why they just can't do this in grams per centimeter cube, but I'll just point that out for the astute observer. Okay. There are two observations that one would pretty quickly take away from this. The first is that up until the 20s, men and women are kind of similar. You go through a profound increase in BMD from the time you're eight years old until

you're about 20 years old. Difference one is that while women maintain a reasonable plateau, they tend to fall quite precipitously in midlife. That's obviously due to menopause. We'll talk about why in a moment. The second thing that jumps out here is the racial difference. So non-Hispanic black has a higher BMD for both men and women than non-Hispanic white, which has a higher BMD than Mexican

or Hispanic, in this case, Mexican American. Again, slight differences in race. Truthfully, I don't know why that is, but it is what it is. To your earlier question, are there differences? Yeah, there are differences on average. I've never, to be honest with you, factored this into my risk assessment except for the male-female one. So in other words, if I look at a patient who's black versus white versus Hispanic, I kind of have never assumed one is at more

or less risk. I've just said, let's do the kitchen sink on everybody. But I think in females, I'm more worried for the reasons that we're obviously talking about. And in looking at this too, and one of the questions we received is when should people do their first bone mineral density scan? When do you want to know that baseline? Because what's interesting when you look at this and you talked about it is from eight to about 20, 22, you see that huge jump and then it kind of levels off. So what would your recommendation be for when people should get their first one done?

Gonna get into a lot of hot water here, Nick, but I'm used to it, right? I've got very unusual recommendations for a lot of things and this is no different. So I think in the spirit of fairness, I'm going to communicate the standard recommendations first. When you look at the American Association of Family Physicians, the American College

of Obstetricians and Gynecologists, the American College of Preventative Medicine, the International Society of Clinical Densiometry, the National Osteoporosis Foundation, and more, the typical recommendation is for high-risk people to be 50, but typically 65 is when they want to start screening people. And that's for women and for men, it's typically 70. It's a lot of credentials you just laid out there. You sure you want to get in hot water with all of those different people?

No, I just simply stating what they're recommending. And if I've misrepresented that, feel free to correct us, but it's typically recommended, as I said, women at 65, men at 70, follow-up scans no more than every two years. Now, for someone who is at serious risk of osteoporosis, which includes men and women over the age of 50, we can adjust those and come down a little bit. Now, the WHO, I think, is a little bit more aggressive and recommends screening women by the age of 40, if I'm not mistaken. As you can guess, I tend to be closer

in my thinking to the WHO. I certainly believe women in their 30s, where we're doing DEXA scans for many reasons, I'm just as interested in their bone mineral density. In fact, when I'm reporting the DEXA results to patients, we have a template that we've made that I really like that lays all of the DEXA information out. Segmental BMD, VAT, FFMI, ALMI, FMI, all of these things, body fat for what it's worth. I always tell them out of the gate, like the one number you care about is your body fat. That's the one I care least about. When we're looking at a 35-year-old patient and their Z-score is already minus one, that's just as concerning to me as if their OGTT shows very elevated postprandial glucose and

insulin levels. And I'm really happy that I'm seeing that at the age of 35 and not 65. I think a natural follow-up there is, because one of the questions we got from a subscriber was how does bone mineral density change throughout the life of men and women? And we kind of saw it a little bit there, but is there anything you want to double-click on or dive deeper on as it relates to that? This is an area where men and women do differ quite a bit. So you've got most of the growth in the length of a bone and the size of the bone is happening

during childhood and adolescence. And that's also when you're really accumulating the bulk of this, the BMD. So if you remember the graph we showed a moment ago, figure five, we don't have to pull it up again, but remember how I said between about the ages of like eight and 20, BMD was doubling. So that doesn't just mean that the size of the bones are increasing, which of course it is, as you go from being eight years old to 20 year old,

you're getting taller, your bones are getting bigger. But that graph was showing you BMD. So that means the density of those bones is also increasing dramatically. So BMD will actually potentially improve up to about the age of 30, but it really peaks in the early 20s. It can stay quite flat, certainly in both sexes, till you're about 40 or 50.

Then bone loss effectively sinks in. But for women, it is much more pronounced. For women, about seven to 10 years around the onset of menopause, bone loss can be 3 to 7% annually. By the time they reach 65, it starts to slow down a bit. So, it might be half a percent to 2% per year. Whereas in men over 65, it's actually a higher rate of bone loss, but they're starting at a much higher point because they didn't suffer that precipitous loss the way women did after menopause. For men at the age of 65, it's usually more typically about 1 to 2% per year. So pull up figure six. When I came across this figure, one of our analysts pulled this up, I was really surprised. So this is for women. This is showing bone mass by age. Again, two things really stand out to me. We've already discussed one, which is you have this pretty significant rise in bone

density between birth and age 20. It then remains relatively plateaued. In this case, menopause kicks in around 50, and then you really start to see the fall. That's the first thing that stands out, and we've talked about that. But look at the other thing, Nick. Look at the dotted line. The dotted line tells you that there's really a totally separate trajectory for this woman, which is if she didn't reach her full genetic potential by the age of 20, she's missed an enormous opportunity

later in life. Remember at the outset I said, this is a podcast you should care about, even if you're a parent of a 10-year-old child. This is why. You want to make sure that your kid's doing the right things when they're 10 to 20 so that they reach their full genetic potential. Now the good news is that let's say you're on that dotted line and you're 30 years old, and I see these patients, right? So, I see the 30 year old woman who's got the Z-score of minus 2 and she's 15 years away from menopause. Well,

the good news is we can get her closer to that solid line by working really, really hard. Now, I don't know if we can get her all the way to that line, but we have this window in time before menopause when we can go through all the stuff we're going to talk about later on minus the pharmacology and try to ratchet up that bone mass so that you get to the highest point when menopause kicks in and you see that reduction of estrogen. Of course, we'll talk about the opportunities there as far as estrogen withdrawal. If you want the next slide, Nick, I want to just talk about one other thing and it really shows where the bone loss is occurring. So in slide seven here, you're seeing for both male and female, the difference between cortical and trabecular bone.

Again, remember cortical is the long shaft part of the bone, the trabeculi are the end. You're seeing the decline for men and women in both of these segments. And I guess what stands out here is where females are losing this BMD. They're losing it primarily in the trabecular or spongy part of the bone. So interestingly, women are no different than men when it comes to the cortical section of bone, but obviously a significant reduction at the spongy part of the bone. Yeah, I mean, it's super interesting

to look at those graphs. And I think you pointed out no matter what age you are, why you should think about this, because especially with people who have children, I know you and I have kids around that age where you think about, okay, that eight to 20 window and what you can do, because if you look at that original

graph and the full genetic potential where they fell off was still higher than the inadequate line of where they plateaued which is pretty crazy to see is for people with kids it's the biggest thing they can do is in that younger age and you've mentioned this a few different times and why don't we double click on it here which is what is it about menopause that creates issues in bone health? Why can it lower bone mineral density? So what do you want to say about that?

Yeah, so bone cells are really interesting. They're what we call mechanosensory cells. So they actually can sense forces. So if you think about how muscles act, a muscle by definition has to have attachments to bones. That's how the system works. And a muscle is never attached to the same bone because then it wouldn't do anything. Contracting muscle on the same bone doesn't do anything. So muscles have to go across joints. So your bicep actually crosses a couple of joints. So you have a bicep that is attached

to the bones of the lower arm and then attached to the bones of the upper arm. And so then when it contracts, it actually closes that angle of the arm. Okay, so muscles are attached via tendons to bones. And think about like what we do with our muscles. Think about the load we put on those muscles. Well, the very simple laws of physics

tell you that the bones have to feel that load. And we often don't think about that. We think about you're doing a curl with 40 pounds, obviously your bicep muscle is exposed to that. But guess what? The tendon that is attaching your bicep muscle is exposed to that. But guess what? The tendon that is attaching the bicep above and below the joint of the elbow is also feeling that. The bone cells actually sense that load.

If you're lifting something heavy, when you're climbing stairs, your bone senses that they need to support a greater force. And in response to that, it remodels by depositing more and more bone tissue. So bone mass increases in the presence of stress. It turns out that that signaling process is regulated very heavily by estrogen. I think this is just so fascinating. You know, when you think of the importance that estrogen plays in reproduction,

I don't have a great answer as to why it's estrogen that is the dominant hormone here as opposed to another hormone. But for what it's worth, that signal of stress that is basically being relayed by the strain gauge within the bone to say, hey, it's time to deposit more bone here. That's modulated by estrogen. And so, in the absence of estrogen, that signal gets reduced. And that's effectively why menopause,

which is a sudden withdrawal of estrogen, is such a devastating thing for women who don't have their hormones replaced. That's why BMD loss is significant in the postmenopausal woman. Now, to be clear, men are also losing estrogen as they age because for men, estrogen comes primarily from testosterone conversion. Testosterone is aromatized into estrogen. A man with a testosterone of 800 nanograms per deciliter, all things equal, is going to have a higher estrogen level than one with 300 nanograms per deciliter. That easily could be explained by an aging phenotype to go from 800 to 300. Now, there are other factors that go into that. Adiposity can give you more estrogen, et cetera. This might be one example, by the way,

of where adiposity helps, because you have the additional weight and load that is a strain signal, and you have more estrogen, all things equal. But men lose estrogen at a far more gradual rate than women, and that's why women experience this loss more significantly. And that's why women are at greater risk for osteopenia and osteoporosis.

One of the questions we received, which I think is a really good follow-up here, is that someone asked knowing estrogen's role in bone health for postmenopausal women, should bone health be a factor to consider in women who are thinking about starting HRT? Well, I'm about to get into a whole bunch more trouble. I'll give you the consensus answer. Well, I'm about to get into a whole bunch more trouble. I'll give you the consensus answer. The consensus answer, I believe, is still no. I believe the consensus answer is HRT is not considered standard of care for postmenopausal bone loss.

And I'll tell you why that's the case. The reason for that is not because HRT was not found to decrease fracture risk, which by the way is the gold standard. That is the single most important metric if you're trying to evaluate if HRT would be beneficial. The Women's Health Initiative, which was published over 20 years ago, was a seven-year study or so looking at the administration of hormone replacement therapy on postmenopausal women. Worth noting these women were far outside of menopause. A hundred problems with this study, which we'll be going into. I already went into actually I think in the podcast

with Avron Blooming and Carol Tavris. People who want to get a better sense of HRT really need to go back to listen to that episode. I think we have an upcoming episode where we'll go into this in more detail. In that study, there was no ambiguity that the fracture risk was decreased in the women taking HRT. However, that study came to what I believe is an erroneous conclusion, and I think what many people now believe is an erroneous conclusion, that the risk of breast cancer and cardiovascular disease went up. Those risks seem to outweigh the benefits of the reduced fracture risk. I think that the increase in the risk of breast cancer was virtually non-existent. It had an absolute risk increase of 0.1%. I think there are lots of reasons we discuss in that podcast as to why that's the case and why that today we can say

with much more clarity that the risk of breast cancer from hormone replacement therapy is virtually non-existent. Secondly, the risk of cardiovascular disease has been completely ameliorated by the adoption of topical forms of estradiol as opposed to oral forms of estradiol. So in that trial, they used oral estrogen, which actually does slightly increase the viscosity of blood. In a susceptible woman, that does slightly increase the viscosity of blood. In a susceptible woman, that would indeed increase the risk of cardiovascular disease. But again, we don't use oral estrogen anymore. That also becomes a moot point. I think today, we actually know that hormone replacement therapy reduces the risk of cardiovascular disease in

women and does not increase it. Again, taken all together, these suggest to me that bone health should in fact be a consideration for women as they consider whether or not HRT makes sense for them. So Peter, another follow-up is earlier you mentioned that there might be some risk factors for why someone might get screened for bone health earlier. What should people be aware of if they're thinking about, if they're maybe at risk, and what are some of those red flags they should look out for? You know, it sounds cliche, but family history matters.

Actually, not something I appreciated until we were getting ready to do this podcast. I didn't realize genetics accounted for up to 50% of bone health. Having either parent that's had a history of a hip fracture, that's a huge red flag. There are other things we want to care about, right? We want to look at fractures related to mild or moderate trauma. You look at somebody who's had a fall from standing height or less, someone who's fallen from such a low height and still had a fracture, that's a huge problem. Another thing we look at is in female athletes. This is really common

actually in female endurance athletes, especially runners where weight is such an important part of the sport. You're punished a lot in terms of performance for extra weight. Same is true in cycling, not as true in swimming. When you look at high-end female endurance athletes, we care a lot about poor nutritional state which can lead to a very low BMI, low body fat percent, and eventually estrogen deficiency. These interrelated conditions of the low bone health, hormone dysfunction, and low BMI are collectively known as the female athlete triad.

That's another big risk factor. Low BMI in general, so anything below about 18 or 19. The other thing we look at is people who have had high exposure to drugs that affect bone metabolism. I think the most common of these that we see is corticosteroids. Now, that's not always systemic corticosteroids, not always people that have had to take lots of steroids for an illness. It can also be inhaled corticosteroids. And we see this actually in a number of patients who had significant asthma as children and used a lot of inhaled corticosteroids. That's not an exhaustive list, but that's a pretty good list to get you thinking about who is at high risk here.

You mentioned it a little bit at the end there, and we did receive a lot of questions on it, which are around the various drugs that may impair bone deposition. So anything more you want to say? I know you mentioned a few of them there, but anything you want to double click on? I think the last big risk factor we look for, and we just saw a patient recently who didn't have any other risk factors, except for the fact that they have a 20 pack your smoke history that is more than 15 years old. So you barely think of this person as a former smoker because they've

been so long without smoking, but they did smoke for 20 years prior to quitting. That is an independent risk factor for low BMD, which in this case, this patient had very low BMD. We actually refer them to an endocrinologist. We know that BMD, the 8 to 20 is such a big age range. If you have someone who is smoking in that age range, the eight to 20 is such a big age range. And if you have someone who is smoking in that age range while bowel mineral density is really going up, do you see it become even worse? That's a great question, Nick.

I didn't know this until, again, we got thinking about this study. There are actually data looking at never smokers, early smokers, and late smokers. Early smokers were defined as people who started smoking before the age of 16 and late smokers, well, it's hard to believe late is considered after 16, but the early smokers were far more impacted. When you look at these people later in life, the never smokers, not surprisingly, had the best bone density. The early smokers had the worst and the late smokers

were in the middle. I don't know the stats about teenage smoking today. I kind of assumed it was on the decline, but this would certainly be yet another reason to avoid smoking at a young age, even if that person goes on to stop at the age of 20. And even if their risk of lung cancer becomes relatively moot by the time they're 50, they may still pay a price for that with bone mineral density throughout their entire life. We also did receive a lot of questions around various drugs that could impair bone deposition.

You mentioned a few of them earlier, but is there anything you want to double click on there? So again, corticosteroids, I think, have to be considered the first and most important one of these drugs you want to be considered about there. So, again, corticosteroids, I think, have to be considered the first and most important one of these drugs you want to be considered about. They do a couple of things. They impair the mineralization of bone by favoring bone reabsorption during the early phase and then they kind of inhibit calcium absorption in the gut.

This area comes up over and over again. Anything that impairs calcium absorption is going to be problematic. It really doesn't need to be mega doses of steroids. People who are familiar with long-term use of steroids might recognize that a dose of prednisone of five milligrams a day is not enormous. Prednisone dose of five milligrams a day is, I think it's actually still a big dose because it's about the physiologic equivalent of how much hydrocortisol a person makes. But nevertheless, that amount is associated with significant reductions in bone mineral density and an increased risk fracture within as little as three to six months of initiation.

Again, just as we saw in the figure that showed how women are primarily losing trabecular bone, it's the same here with cortisol. That doesn't mean you should never take corticosteroids. There are lots of conditions where corticosteroids are going to save your life. It means you have to be aware of these things and you're going to have to work a lot harder to counter their effects. And we'll talk about some of those things. Another class of drugs that I get asked about a lot is proton pump inhibitors, PPIs. And I would say the data here are less clear. There are studies that have assessed the relationship between PPIs and they do show an increase in osteoporotic

fracture. The most likely mechanism suggested is again intestinal calcium absorption, so anything that interrupts that, which then goes on to interrupt osteoclast formation and bone remodeling. But I want to be clear that this is not nearly as well understood as the case is for corticosteroids. There are a number of observational studies that show an increase in the risk of fracture. Then we look at large meta-analyses that don't find a statistically significant decline in BMD with PPI use. I think you just have to be smart about this. don't find a statistically significant decline in BMD with PPI use.

I think you just have to be smart about this. There are lots of reasons we're going to put patients on PPIs. If a patient has significant reflux that is not amenable to other treatments, we're going to put them on a PPI. If a patient has Barrett's esophagus, we're putting them on a PPI. It's non-negotiable. So it just means that we have to be thoughtful about, is the drug really indicated? If it is, what else can we do to reduce the risk down the line? I think the final class of drugs that tend to have a similar association, although probably from a different mechanism, are some of the anti-epileptic drugs.

One in particular, which is phenytoin, so a super common anti-seizure drug. Here I think the mechanism might have more to do with liver inducing an enzyme called cytochrome P450 that leads to increased catabolism of vitamin D. That, of course, you may recall, will lead to decreased absorption of calcium in the gut. I don't know if anybody's done a study, but it seems to me that a no-brainer study would be taking patients on phenytoin and supplementing them with lots of vitamin D

to see if you can overcome that. But again, phenytoin is a common drug within the world of anti-seizure meds, but in the big picture, nowhere near as common as corticosteroids and proton pump inhibitors. I think where we're going to go next is starting to look at what people can do to improve their bone health.

I think we laid a lot of the groundwork that we need to do and this next section will get into everything people can do to improve it individually. But before we get to how you the person can do it, we did have some questions from subscribers who said they have kids and they want to improve their bone health. And we've talked about how important it is. So before we get to the individual, is there anything in particular, any advice you would have for people who have kids on those very important ages, you know, the eight to 20 on what they can do so they can really optimize the bone health?

I think this is very important. When I stopped to think about all of the things that parents got on their plate to try to help their kids with during this relatively narrow window that your kids are in your house and therefore somewhat amenable to your influence. The most important thing probably comes down

to being adequately nourished and being very active, and in particular, being very active in things that load bones. One of the things that was a bit surprising to me was that running didn't have a greater impact on BMD. So in a moment we'll pull up that figure, Nick, that I think is pretty interesting that shows all of the different sports and how they impact BMD.

Now, I'm going to posit that the running one has a confounder in there. Because if you think about it, running puts a lot of force on muscles, especially when you think about the hips, which are two of the three bones that are attached to muscles that experience great force during running. So why is it that running where you're potentially, at least at the knees, experiencing eight times your body weight with each impact, why wouldn't that do more? And I've been thinking about this for some time, and maybe somebody knows the answer, but my suspicion is that the confounder here is body weight and BMI, and that when you

talk about elite runners, and usually when you talk about elite runners, and usually these are studied in elite runners, they're very weight conscious. Running and cycling are the ultimate strength to weight ratio sports. I do wonder if we're seeing basically malnourished runners. What do I mean by that? Basically, people that are BMI is too low, might be perfect for being a runner, but it's too low for optimizing bone mineral density. I guess this is a long-winded way of saying running might not be enough. Obviously, running is a great thing to do

and it comes with a lot of benefit, but you probably want to make sure that your kids, both boys and girls, are doing other sports that involve more power. So probably things that involve jumping and actually lifting heavy things. This is kind of a great plug for rucking. I mentioned Michael Easter briefly at the outset. One of the things that Michael writes about in his book, The Comfort Crisis, is the importance of just walking with heavy

stuff. Either doing a farmer's carry, doing a ruck, which I love. I try to ruck five days a week, backpack with heavy weight in it and just walking around and always trying to find a hill to walk up and down, kind of loading myself without the knee joints being susceptible to that. Going back to the kids, I think we just want to make sure BMI is not too low, hormone dysfunction is not there, energy availability is there, body fat is not too low, all of those things that tend to occur. Obviously, smoking, we obviously want to make sure nobody's

smoking, but as we just talked about, kids beneath the age of 16 are uniquely susceptible to this. So again, it's pretty straightforward, lots of nutrition, lots of physical activity and specifically physical activity that builds muscular strength because I think that's going to apply the greatest force to the bone and the bones as we talked about are mechanical sensory entities that are going to remodel in proportion to how much mechanical stress they're under. So lifting heavy stuff matters. And that doesn't mean that 12-year-olds need to be deadlifting three times their body weight.

But we also don't want to shy away from kids lifting things. When you were talking there about the running, I don't think it came up on the Ryan Hall podcast, but it would have been really fascinating if he ever had a DEXA scan when he was in peak running shape compared to his current body type, just with all the muscle he put on just to see the difference in his BMD. You know, that's such a good question. I'm going to email Ryan as soon as we're done and ask him because you got to think at his level being one of the best runners in the world that they had a DEXA scan of him at the time. And yeah, I'd love to know what his BMD was

when he was 28 versus what it is today. The next set of questions fit perfectly with where we're going, which is a lot of questions on what does physical activity have to do with bone health. You kind of hinted at it. We got a lot of questions on, are there certain types of physical activities that is better for bone health than not. We talked a little bit about it just now with kids, but as people who are adults are also

thinking about this, what would you say to them? Well, again, I just want to go back to what it is about muscles that have such an impact on bones. This is not always clear. The more force that a muscle is applying to a bone, which is directly related to how much force you're trying to put on the muscle, picking something up, contracting a muscle under an enormous external load. By the way, I think that can be isometric. I don't think that has to be isotonic. In other words, I don't even think the muscle has to change in length necessarily

for that force to be experienced. There are lots of safe ways to do this. You're applying force to the receptors there. Those receptors are translating that tension into signals that say lay down more bone. We looked through some of the literature on this and I got to tell you, this is one of those things where I was surprised. I saw some things that I just didn't expect to see. I already mentioned one of them. I thought running was going to be really great. It turned

out that studies looking at resistance training found them to be significantly better at retaining BMD when compared to anything aerobic, running, swimming, cycling, and even impact things like pure jumping. So powerlifting turned out to be more effective than just regular strength training in maintaining BMD in post-menopausal women. So think about that for a second. When we talk about power lifting as a sport, we're talking about, and I've seen women do this at all ages, we're talking about someone doing a squat, a deadlift, and a bench press. And the squat and the deadlift, that is lumbar spine, that is hip. I mean, that is really stressing the lower body more than just going into the gym and lifting. Then we talk about high force impact

sports such as football and MMA were associated with the highest BMD values. I know you do MMA, at least vis-a-vis Jiu Jitsu, so you can probably speak to this more about why it's exhausting. I was having dinner with Joe Rogan the other day, and we actually talked about this. It's such a big part of his life, and I know nothing about it. He made a comment that nothing exhausts him more than his jiu-jitsu workouts. Joe does so many things. I was kind of surprised that he said

that that is the single most exhausting thing he does. But I'm guessing you can relate to this? There is nothing more tiring than that, especially on hard rolls. I mean, I don't know the physiology behind it, but you just have to go so hard. Your muscles are pushing, pulling. Your mind is also going, so it's not like you can zone out.

But there'll be days where you have really, really hard rolls and you just finish and you just lay there in a heap of sweat for about five minutes before you can do it. I do get questions. People who know you and know me, they're always like, I'm surprised Peter doesn't do Jiu-Jitsu because it seems like something you would love. I think if it wasn't for the injury aspect of it, because that's a huge concern, it's not really the most longevity-friendly activity you can do.

A younger you would have been a killer out there. You would have loved it. I just can't count the number of friends I have that are so obsessed with Jiu-Jitsu. Even in high school, one of my closest friends who was a really good wrestler when I was a boxer, he was the first person I ever knew who did this. This was back when you were just starting to hear about the Gracies. Now, we're talking early 90s. At least that was the first time I ever heard of the Gracys brothers from him. There's probably like two jujitsu gyms in Toronto and he used to train in this stuff. But yeah, I've had so many friends that have done this and it looks incredible, but it doesn't appeal to me in any way, shape or form. On the flip side of that, these low weight bearing, low impact things like walking, swimming,

cycling, don't really seem to do a lot to improve BMD. Again, I don't know if the studies hasn't been done, but my suspicion is that when you make those things a little bit harder, especially with walking with a rucksack and walking uphill, you're going to apply more strain. Also walking downhill. Again, when I'm rucking, I'm always trying to find the maximum elevation change. Walking uphill is harder cardio,

but the walking downhill puts more strain on the muscle. And again, the take-home point here is the more this strains your muscles, the better this is for your bones. I'm gonna pull up that figure as well that you mentioned earlier, which puts metrics and colors and graphs for people to see this too.

Yeah, this is an interesting figure. On the left here, you're just looking at the absolute BMDs. You may also recall just where these units sit. All of these athletes have very high BMDs compared to what we were looking at as the average man and the average woman. We don't have to flip back to that, but I just am familiar with the numbers. 1.2 grams per centimeter squared was considered a

really good BMD for a middle-aged man or woman. Do you remember how we've seen that number 1.2 is pretty common? Okay. So when you're looking at this, just to put it in perspective, even the swimmers or the resistance training females, and females are tending to be a little bit lower than men, they still have excellent BMD. So I do not wanna be suggesting that some sports are bad for BMD. That's not the take home message here.

The take home message here is, if you really have to juice it, what do you wanna be doing? Again, even the distance runners here, look at which ones separate men versus women, right? So for example, red versus green is showing you the difference between male and female resistance training, whereas all the swimmers, all the distance runners, all the track and field athletes are in the same bucket. Now again, compare distance to track and field, what's the difference?

Track and field, more power. A sprinter has more force being applied than a distance runner. What I find amazing is the MMA and the football. I mean, just staggering. Now, I'm going to say something else that's kind of unpopular. Not really sure playing college football is a great strategy for increasing your BMD when it comes with so many other injuries, not to mention all the head trauma. So, the purpose of this analysis is not to say you got to go be a college football player. No, it's to just give you a sense of what not to mention all the head trauma. So the purpose of this analysis is not to say, you gotta go be a college football player. No, it's to just give you a sense of what types of forces

are involved in generating higher BMD. And I think most people who have even watched a football game can appreciate the kind of forces that those athletes are experiencing. And as you talked about with MMA, incredibly strong forces applied across muscles transmitted to bones. Good for the bones, bad for the brain.

Right. So what's the sweet spot here? To me, the sweet spot is resistance training. All of these things come with risk. If you don't do them correctly, I mean, hell, if you don't swim correctly, you're going to tear your shoulders apart. So we just have to think about this through a risk reward lens. MMA, I don't know anything about it, but I'm guessing it can be done safely.

I'm guessing there were ways to do it and not be, you know, not put yourself at risk to tear your meniscus or tear your shoulder or have a lumbar spine disc blow up because you get folded in half, like a pretzel, you can hurt yourself resistance training, but also you can not, if you're going to take one thing away from this, just notice that walking isn't on here and gardening is not on here and golf is not on here. I want people to understand that if they're in the business of trying to increase their BMD, they have to get wicked forces on their muscles.

I feel like you didn't have to do golf like that. I feel like out of every... I know. I'm making enemies like I'm just killing myself today here. I know. I feel like that has the potential to be the most thing that we get feedback for. You can insult the different organizations, but once you talk about golf like that, there's no coming back.

And I'm not saying don't play golf. Look, race car driving is not on here, OK? Archery is not on here. My favorite things in the world aren't on here. Is that an appropriate mea culpa? The things I love doing is not on here. My favorite things in the world aren't on here. Is that an appropriate mea culpa? The things I love doing are not on here. I just don't want to be diluted into thinking that all that time I'm in a race car, I'm increasing my BMD.

It's not enough. I got to be in the gym. I got to be hitting it. So Peter, we talked a little bit about early on the danger of low BMI or extremely low BMI for bone mineral density. And then everything we just talked about on lifting weights, the more muscle you put on, you're potentially gonna go up in weight.

What about people who are overweight and they lose body weight? Does that have an impact on their BMD? It does. And this is actually super interesting stuff. We know, for example, that when people lose significant amounts of weight, they're usually losing lean tissue as well.

It's one of the tradeoffs. In some people, it's totally reasonable tradeoff. You see somebody who's already got an appendicular lean mass index at the 90th percentile and their fat mass index is at the 99th percentile. You're going to have them lift like crazy during weight loss because you want to keep that lean mass up. Maybe it falls to 70th or 80th percentile while you try to get fat mass index down to 60th or 70th percentile. What about the impact on BMD? Well, there's no question that the correlation between weight loss and a decrease in BMD,

exactly what we don't want to see in the obese, in particular in the elderly, is very strong. But it turns out that there are two different strategies for how you can go about losing weight, and the strategy may impact the outcome. We know that anytime you lose weight, there has to be a caloric deficit. You can't lose weight without a change in stored energy. Losing weight is changing stored energy. Stored energy requires caloric imbalance. But when you look at data for people who have lost weight purely through nutritional manipulations, i.e., purely through manners of reducing caloric intake, and you can do this a lot of ways,

you can just directly and generally reduce calories. You can do it through time-restricted feeding. You can do it through dietary restriction, meaning restricting various elements within the diet. Those people tend to lose bone mineral density. When you look at people who are doing it in combination with significant exercise, they actually tend to gain bone mineral density. In other words, you can have people

losing the same amount of weight. Some of them are losing BMD, some of them are slightly gaining it. What could be going on there? It's been suggested that the BMD reduction due to weight loss may be caused less by the mechanical loading of bones and more by a change in some of the adipose derived factors like leptin and adiponectin and other hormones that move

around when weight loss changes. So leptin goes down, adiponectin goes down. Obviously we talked about the fact that especially in men when they lose weight, but potentially in women too, we see estrogen going down. So it could be that when you're loading the muscles and therefore transmitting that load to bones, you're offsetting some of that. Now again, the study that I'm citing is relatively small and the group that was using exercise as their primary tool to lose weight didn't lose quite as much weight. Even when that's corrected for, it could be a little bit of a confounder. I would just say intuitively, this makes sense.

More importantly, from a longevity standpoint, it makes sense. I mean, exercise, you've heard me say this a hundred times. It's the single most important tool we have anyway. Why wouldn't we employ it as an important part of a weight loss strategy if this is just one of the other bonuses that comes with it, which is an ability to minimize the BMD loss that is almost inevitable with weight loss? Moving from exercise to nutrition and supplements, we do get a lot of questions on how nutrition supplements can impact BMD. One of the first questions we got was,

what are some essential nutrients that are important for optimizing bone deposition that people should think about? If you don't mind, pull up figure 12. One of our analysts put this together, and I think it's a great way to lay all of this out. I think there are the big three you want to think about. There are other things that matter. Protein matters, total calories matter, all of those things other matter. But when we think about the micronutrient side, the big three are calcium, vitamin D. And when I say vitamin D, I mean D3 and magnesium. In the first

column here, you can see the required daily amounts. And I consider this a minimum. This would be like a letter grade C. You might want to think about having a B or an A. So calcium, about 1,000 to 1,200 milligrams daily, vitamin D, 800 to 1,000 IU daily, and magnesium, 300 to 500 milligrams daily. Now, these can be supplemented. So if you can't get this in food, if you're not sufficiently getting this, either through sunlight, in the case of vitamin D in food, calcium carbonate, calcium citrate are reasonable options. In the magnesium school, it really depends on what your gut can tolerate. Magnesium citrate, glycinate, and oxide are fantastic if you're looking for a little speed

up of the bowel. If you aren't, you want magnesium carbonate. It's also worth noting magnesium carbonate more fully absorbed than mag oxide, citrate, or glycinate, which is actually why those three help with bowel regularity. Personally, I like to mix them up. I'm sort of using three forms of magnesium, so I'm supplementing with mag carbonate in the mornings. I use mag oxide at night, and I also use a bit of mag glycinate with L3 and 8 as well. I'm routinely hitting about a gram of magnesium supplemental.

Then the final column here is you can sort of see the foods where these things reside. You can see why I believe most people are magnesium deficient. It's pretty hard, I think, to get 500 grams predictably of absorbed magnesium every single day. By the way, I think that's a real minimum. I think a gram is really where you want to be. You got to do a little bit of work to make sure you're getting that from your nutrition. Calcium is a bit easier to get if you consume dairy, but look, a lot of plant-based people

aren't going to eat dairy. They have to look to other things. Some of those other things, I don't think you really want to be eating a bunch of. Like look at how high figs are, dried figs, a cup of those is 300 milligrams of calcium. So that's quarter of your daily minimum amount, but I don't know that I want to be eating a cup of dried figs every day for other reasons. I love tofu, but I'm not eating it every day.

So I think this is something we need to be paying reasonable attention to, both from a dietary standpoint, and then for a number of us us also from a supplementary standpoint. What about pharma drugs? We did receive questions on what are the options, what are the benefits, what are the tradeoffs, what should people be thinking about there as they explore their options? Yes, so drugs are typically last line of defense.

Just to give you a sense of how last line of defense that is, we personally in our practice do not prescribe these drugs. The reason for that is we're just not expert enough to do it. I like to send people to experts when something is out of our hands. For example, we completely run the gamut of all lipid-lowering drugs because we have great expertise in that. When it comes to this class of drugs, we refer patients out who need them to endocrinologists. Basically, I think there's three big classes. The lion's share is one class, which are the bisphosphonates. This is a class of drug that strengthen bone by basically slowing the rate at which the osteoclasts remove bone.

Remember osteoblast be for build, clast being the opposite, they just remove it. These exist in two being the opposite, they just remove it. These kind of exist in two subtypes, nitrogen containing versus non-nitrogen containing, but the lion's share of these, there's kind of three big versions of these. So the nitrogen containing ones are the much more common one. I would say people are probably familiar with some of these, so Boniva, Fosamax, Actinel, those are the big ones. And the studies are are pretty clear. These things work. They increase BMD by about 4 to 6% in the critical areas that matter, the femoral neck, the hip, the lumbar spine, and they reduce the risk of fractures. The drawback here is they're typically not used for indefinite periods of time. They're discontinued after about five years. The evidence suggests that that might not increase the risk of fracture going forward.

It might be that you get the value during that five-year window, you rebuild the bone and you maintain some of that value. The other two classes of drugs here, personally, I don't have a lot of experience with. I haven't even seen my patients be prescribed these, but one of them are monoclonal antibodies and then the other is just synthetic parathyroid hormone. I don't know a lot about those two, to be honest with you. We do have some data, I think, here. We have a pretty good meta-analysis that shows the efficacy. I think it's slide nine, Nick. Perfect. Got it. You're looking at the classes of drugs. Okay. So, let me just help people read this a little bit. The first drug there on each list, that's synthetic PTH.

Anytime you see an AB on something, at the end of it, that's the monoclonal antibody. The other drugs that end in ATE, those are all the bisphosphonates and then the rest are pretty straightforward, calcium, vitamin D, et cetera. If you go over to the right, you're looking at odds ratios. Remember, anything that is on or

crossing the unity line of one means it's not significant. Then anything that's to the left of that line, if the confidence interval doesn't cross the one is significant. What you can see here is nothing that's on this list is increasing the risk of fractures. About two-thirds of these things in their various formats are reducing the risk of fracture for either hip fractures, vertebral fractures, or non-vertebral fractures. And for people who are looking at this and aren't familiar with this type of graph, when you say to the left of one, it's not the whole black bar, you're looking at the little white box, right? No.

So the whole black line has to be to the left of one for it to be significant. The black line is your confidence interval. So for example, let's look at the very first one. You'll notice that the little white line is way to the left. In fact, it's probably 0.4 or something. In fact, if you go and look, you can see it tells you it's 0.42. That's huge, right? That's like a 58% risk reduction. So you think, well, that's got to be great. But I can tell you right now, it doesn't matter because the confidence interval is so wide

that it crosses one. That tells me without looking at anything that the p-value is greater than 0.05 and the confidence interval crosses unity. So when you look over, sure enough, lower limit, 0.1, upper limit, 1.82, p-value, 0.24. Okay, let's pick a winner. Let's go two down from there. Actually, these p-values are so small, they're probably less than 0.001. But again, so the one beneath that has a very similar little white dot, it's 0.45. So it's not quite as low, but it's a 55% reduction. But I know it's going to be significant because the confidence interval doesn't cross one. And sure enough, it doesn't. It's 0.27 to 0.68. And the p-value is probably 0.000. You know, it's less than 0.004. They only just show them to two significant figures here.

For people interested in diving deeper into that, that AMA you and Bob did on understanding studies and studying studies dives way more into that. Peter, one of the things we haven't really talked about yet is what happens in something like space or low gravity environments? What happens to your bones if you truly aren't using them? This is obviously not a subject that is relevant to a lot of people directly. Indirectly, it's relevant to a lot of people. Space is just the most extreme version of what we would call disuse osteopenia. As the name suggests, disuse osteopenia occurs when bones are chronically

unloaded, leaving to a very unfavorable combination of high bone resorption and low bone formation. It's the same thing that's happening with the osteopenia from aging. It's just much more accelerated and much more extreme. So again, the most extreme version of this is astronauts. I don't know much about what they do in space, but I suspect that they go out of their way to figure out ways to load astronauts in space so that they don't have to deal with this in its highest form. But I think for most people where this is relevant is bed rest. So lots of people have to undergo bed rest for all sorts of reasons. Pregnant women often are placed on bed rest if they are experiencing

fetal retardation. And I mean that not cognitively but growth retardation. If in the third trimester, the fetus isn't growing at the rate that is expected, not uncommon that the OB will ask the mother to gradually reduce her impact until more and more energy can be reserved for the fetus. You can also see bed rest being necessary for various types of injuries. Of course, we know today that we don't want to rest people nearly as much as we used to. There was a day 50 years ago when if somebody hurt their back, they were put on two weeks of strict bed rest. Today, we know that that's absolutely the last thing you want to do. Bone loss due to dysuse osteopenia is incremental and it's

progressive with time and it occurs more rapidly as you would guess in the trabecular bone than in the cortical bone. This is the trend we've seen over and over again. And frankly, it can be about 2% per month in micro gravity, partial paralysis, which I should have mentioned as well, paralysis based injuries or immobilization with injury and in the most extreme setting with complete paralysis, it can be up to 7% per month. So Peter, for people who are experiencing that type of immobility, is there anything in particular they should be thinking about or they can do

to kind of help with the BMD concern? The first would be any form of PT that can actively load muscles. I actually don't know how much data exists on this, but that's one of the things that I think is interesting about cyclic BFR, and that's why the minute I was out of surgery, I got permission from my surgeon to put my cats who cuffs on my arm and just start cycling the BFR.

I wanted to put little bits of stress on that bicep just to have it moving. And again, keep in mind, I was very fortunate. I did not have a bicep tendon repaired. If I did, I would not have been allowed to do that. I had to keep my arm completely immobilized, but I was still able to get compression on the bicep. Let's say you're bedridden with a certain injury. There are still other muscles in your body that don't pertain to that injury that can still be moved and put under load. Even if you're doing these things isometrically, so a person is holding you and you're resisting against them without actually moving in the bed, that's important. Now, there was a super interesting mouse study that we found that

used a bisphosphonate to inhibit the osteoclastic bone absorption in a mouse model where the mice were given botulotoxin to basically prevent them from moving, I think, one part of their leg. I think we have this figure here as well. Yeah, it's figure 10. Perfect. I got that pulled up. So what you're looking at here is in the first bar on the left is the baseline, and then you have control mice in black, and then in white, you have what happens to the animal

that we're just given botulatoxin. So these were the animals that were basically immobilized because botulatoxin of course paralyzes their legs. And then the botulatoxin plus the bisphosphonate on the right. I think this is a pretty profound result. You're looking at this in the femoral neck and in the middle of the upper part of the femoral bone below the neck. And you can see that the bisphosphonate plus the immobility really looks no different from the control. It's a clear contrast to how the untreated animal looks. Look, these are 16-week-old female mice. Is that going to be true in humans? I have no idea, but I find this type of research very interesting. And frankly, I hope more people are doing this type of research

because I think immobility is a huge problem with everybody. But once you start to deal with an aging population, it becomes more significant. How many times have we talked about that study where a group of 65-year-olds, I believe, were immobilized for two weeks and lost, if I'm not mistaken, something in the neighborhood of about four pounds of lean mass in two weeks. We talked about that through the lens of how much you lose lean

mass, but think about what that's doing to BMD and think about how long people are immobilized beyond two weeks, especially as they're older. I can't remember offhand, but I know you and Inigo in the second podcast also talked about lactate as it relates to immobility for people on bed rest or in the ICU as well. We'll link to it in the show notes, but you also had a conversation about the importance of people in the hospital just moving for the lactate level.

So we've seen it over and over across a lot of podcasts. That was a pretty exhaustive tour of all things Bone, but I think this is super important stuff. I know it's not that sexy. You're not going to see too many Twitter wars about BMD, although I did probably provide enough substrate for someone to get upset about something I said today, whether it be my position on golf not being the perfect BMD boosting sport or my recommendations for earlier screening on BMD.

I think there was something else I said that will draw the ire of critics. Yeah, we just better hope that one of those organizations doesn't sponsor an ad in Golf Digest because then we'll just get it from all fronts. But hopefully it answered a lot of questions. Again, we compiled these questions. We've gotten them a lot and we've never tackled it at this level. And like what we did with muscle and looking at the importance

of muscle strength, muscle mass, what improves there and then looking on the other side out of the bones too. So hopefully people enjoyed it and until the next AMA, we'll see ya. Don't stay up too late watching Ozark, new season tonight. I don't get to even start it tonight. How do you have that self-control? Jill and Olivia are out of town for a volleyball tournament. Don't stay up too late watching Ozark, the new season tonight. I don't get to even start it tonight.

How do you have that self-control? Jill and Olivia are out of town for a volleyball tournament. So I'm solo with the boys this weekend and Jill would kill me if I started it without her. Yeah, something tells me you won't have a lot of solo time solo with two boys either. So you'll probably have your hands busy. I will. Well, good luck with that.

Thanks, man. We'll see you. Bye. Thank you for listening to this week's episode of The Drive. Head over to PeterAteaMD.com forward slash show notes if you want to dig deeper into this episode. You can also find me on YouTube, Instagram, and Twitter, all with the handle PeterAteaMD. You can also leave us review on Apple podcasts or whatever podcast player you use.

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