The Peter Attia Drive - #84 - AMA #10: Low testosterone, hypothyroidism, building muscle (and preserving it while fasting)

Episode Date: December 16, 2019

In this “Ask Me Anything” (AMA) episode, Peter answers a wide range of questions from subscribers. Bob Kaplan, Peter’s head of research, asks the questions. If you’re not a subscriber and listening on a podcast player, you’ll only be able to hear a preview of the AMA. If you’re a subscriber, you can now listen to this full episode on your private RSS feed. You can also listen to this full episode on our website at the AMA #10 show notes page. We discuss: Does testosterone supplementation impact longevity? [2:40]; Under what conditions does Peter decide to treat patients who have low testosterone? [8:50]; Are there risks involved with testosterone replacement therapy? [17:10]; How does Peter diagnose and treat hypothyroidism? [21:30]; How might someone do time-restricted feeding while also adding muscle mass? [26:30]; If building muscle requires higher levels of IGF-1, should we be concerned about longevity? [34:45]; How to preserve muscle mass while fasting [41:45]; Is it possible to simultaneously lose fat and add muscle mass? [46:30]; and More. Learn more: https://peterattiamd.com/ Show notes page for this episode: https://peterattiamd.com/ama10 Subscribe to receive exclusive subscriber-only content: https://peterattiamd.com/subscribe/ Sign up to receive Peter's email newsletter: https://peterattiamd.com/newsletter/ Connect with Peter on Facebook | Twitter | Instagram.

Hey everyone, welcome to the Peter Atia Drive. I'm your host, Peter Atia. The drive is a result of my hunger for optimizing performance, health, longevity, critical thinking, along with a few other obsessions along the way. I've spent the last several years working with some of the most successful top performing individuals in the world, and this podcast is my attempt to synthesize what I've learned along the way to help you live a higher quality, more fulfilling life. If you enjoy this podcast, you can find more information on today's episode and other topics at peteratia-md.com.

Welcome to another edition of Ask Me Anything. Once again, I'm joined by my head of research and my sidekick, Bob Kaplan. In this episode, we go really deep on about three things. There's no speed round, but I think we make up for it by just the depth rather than the breadth. So the first thing we talk about is testosterone replacement for men specifically. When it's appropriate, related risks, benefits, the laboratory values one should and shouldn't care about.

So apologies that this one is a little more gender specific, but I think we've also already covered this on the female side. So this is a very male centric view of testosterone replacement therapy. Second thing we jump into is thyroid replacement therapy and just in general thyroid hormones, how they're produced, how the diagnosis of hypothyroidism is made in my opinion, how that differs from maybe the standard way that people think about it and all sorts of other tangential things around that. And then lastly, we talk about exercise.

And specifically, we talk about exercise and how it relates to nutrition with respect to building muscle. Now, to be completely clear, and I disclose this fully in the episode, I don't consider myself an expert on muscle building bodybuilding, anything like that. You certainly wouldn't want me as your coach if you were training for such things. But at the general population level, which is where I consider myself to be, I think I hopefully know enough to add value here. So anyway, we talk a lot about the role of fasting, caloric restriction up and down, and muscle accumulation versus loss of muscle. We also talk about a topogy, IGF,

or insulin-like growth factor, and M-Tore in the process. So without further delay, here is AMA number 10. As a reminder, AMAs are for subscribers only. If you're not a subscriber, you'll only be able to hear a preview of the AMA here. To become a subscriber to have access to the members only podcast feed, as well as other benefits such as detailed show notes and member-only discount codes in the products I believe in,

you can visit peteratiaemd.com forward slash subscribe. Hello, podcasters. Welcome to another Ask Me Anything. I am joined by Peter Atia. This is Bob Kaplan. Peter, how you doing? I'm doing good, Bob. How are you? Doing well. I thought we'd just jump right into it. Start off with some testosterone. Wow. No for play. Go for it. Yeah. A lot of questions around testosterone. The essential question is, are you a fan of testosterone supplementation as men age? If so, to what targets? Well, I mean, this is sort of a tough question. It's very difficult to answer these questions in isolation because they're kind of dependent on individual patients. Bear with me, I guess,

opposed as I kind of give us soliloquy. Regardless of what you're talking about manipulating in medicine, you should ask yourself the question, what is the desired outcome? Am I manipulating this variable because I believe it improves longevity? If so, does it improve lifespan?

Does it improve health span? Both, neither. One more than the other. Testosterone, let's just now evaluate testosterone replacement through that lens, which is, what do we believe it can help with? Well, I'm not really particularly convinced that normalization of testosterone will improve lifespan. I could be wrong on this. There are certainly associations that would suggest that that could be the case. For example, low testosterone is not only associated with prostate cancer, but is associated with more aggressive prostate cancer.

By the way, I think that that's probably not saying that low testosterone causes aggressive prostate cancer. I think it says that if you have prostate cancer in a low androgen environment, it is likely to be more aggressive. We could probably spend an entire AMA just debating the merits of testosterone replacement therapy, but I, in spending a lot of time in this literature, I don't see a clear and obvious case that one will live longer because of it. And again, living longer by definition means delay the onset of death. At least as it pertains to chronic disease. So then I would sort of turn the table a little bit and say, well, is there evidence that it improves health span? Well, health span again has three components. One of them

is cognition. One of them is sort of physical exoskeleton for I still got to come up with a better name for this one, Bob. So we got I hate saying exoskeleton because it sounds I don't know like I'm talking about a grass hopper or something like that. I always think of the terminator. Okay, even better. And then the third one is emotional health, well being happiness, et cetera. Now I think the testosterone can have a pretty significant impact on two of those three, which one's the odd man out.

I'm not convinced that testosterone has an impact on cognition. This has actually been studied once and we'll link to the study in the show notes. It was studied quite recently, meaning in the last two years. The study had its limitations, but it did not suggest that testosterone replacement therapy was improving cognition. Now, I know that there are a lot of people out there, a lot of physicians out there who prescribe TRT, who would disagree with me on that and would say that empirically it appears to. Maybe that's the case, that and would say that empirically it appears to, maybe that's the case, maybe it's not. But as a selling point, I generally don't say to men, normalization of your testosterone

is going to improve your memory. Again, who knows what the placebo effect can mean in the situation, but I generally by and large don't think that that effect is there. And if it is there, I don't think it's that strong. Let's go to the area where there is absolutely no denying the benefits of testosterone replacement therapy, which is the improvement of endormatinins of lean muscle mass, strength, conditioning, recovery from exercise,

all of these things. They all fit into this bucket of how does your physical body work? And there is no doubt that testosterone improves those things. The magnitude that those things are improved, however, is not obvious and is not entirely predicted by the number. So let's come back to that Bob if you can remind me because I want to really go into that. But just for the sake of completeness, let's turn our attention to the last piece of health spin, which is sort of happiness and emotional health, can testosterone improve those things. I'm a bit embarrassed to say I don't know how rigorously this has been studied,

but the effects would be difficult to miss if you've ever treated patients with low testosterone, who then respond favorably, which is to say, you know, mood can get better, libido tends to get better. And maybe those two things alone are worth the price, you know, worth any risks that are going to be associated with testosterone. Because someone whose libido is shot, who now all of a sudden has, you know, desired have sex again and intimate and be all those things, that alone could be a benefit to a person's relationship and therefore to a person's

life. So in summary, what am I saying? There's four things we think about, right? Living longer, improving cognition, improving physical body, improving emotional health. I think two of those three probably are impacted positively by testosterone. I think two of those three are probably less so. And yes, there are lots of ways that having more muscle mass can also delay death. So notice, I said chronic death when I was talking about death, but of course, it might be the case that testosterone replacement therapy can improve muscle mass and functional strength. They can later in life prevent accidental death, which is probably the fourth leading cause of death when somebody is old enough.

Okay, I said way more about that than I wanted to and I have not answered the question yet, but do you Bob have any questions about everything I just said or can I now go to the next part of this? No, that sounded good. I know that we looked into testosterone, did some research on it, and I remember seeing the the Endocrine Society, their recommendations for TRT were for symptomatic men with low T and they had the following purposes, which sounds like you pretty much nailed them all, improve sexual function, improve sense of well-being, improve muscle mass and strength,

and increase bone mineral density. You can find all of this information and more at pteratia MD.com forward slash podcast. There you'll find the show notes, readings, and links related to this episode. You can also find my blog at pteratia MD.com. Maybe the simplest thing to do is to sign up for my subjectively non-lame once a week email where I'll update you on what I've been up to, the most interesting papers I've read, and all things related to longevity, science, performance, sleep, etc. On social, you can find me on Twitter, Instagram, and Facebook, all with the ID, Peter, ATF, MD. But usually Twitter is the best way to reach me to share your questions and comments. Now for the obligatory disclaim. This podcast is for

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