ZOE Science & Nutrition - Recap: Rethinking rest - cancer treatment and exercise | Dr. Jessica Scott

Episode Date: April 22, 2025

Today we’re talking about the relationship between cancer treatment and exercise. For years, the standard advice for someone going through cancer treatment has been simple: just rest. The belief has long been that the body has to slow down and conserve energy to cope with the intensity of the treatment. However, recent research is challenging this long held notion. What if your body doesn’t need to slow down - what if it actually needs to speed up? Today, I’m joined by Dr. Jessica Scott, whose groundbreaking research is reshaping our understanding of the best path to recovery for cancer patients. 🥑 Make smarter food choices. Become a member a zoe.com - 10% off with code PODCAST 🌱 Try our new plant based wholefood supplement - Daily30+ *Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system 📚 Books from our ZOE Scientists: The Food For Life Cookbook by Prof. Tim Spector Food For Life by Prof. Tim Spector Every Body Should Know This by Dr Federica Amati Free resources from ZOE: Live Healthier: Top 10 Tips From ZOE Science & Nutrition  Gut Guide - for a healthier microbiome in weeks Have feedback or a topic you'd like us to cover? Let us know here Listen to the full episode here

Hello and welcome to Zoey Recap, where each week we find the best bits from one of our podcast episodes to help you improve your health. Today we're talking about the relationship between cancer treatment and exercise. For years, the standard advice for someone going through cancer treatment has been simple – just rest. The belief has long been that the body has to slow down and conserve energy to cope with the intensity of the treatment. However, recent research is challenging this long-held notion. What if your body doesn't need to slow down? What if it actually needs to speed up?

Today, I'm joined by Dr Jessica Scott, whose groundbreaking research is reshaping our understanding of the best path to recovery for cancer patients. Tell me about what your research has discovered about exercise and cancer. Yeah, so with exercise, oncology is a fairly new field. Again, 20 years ago, the message was just rest and take it easy. So one of the first layers of evidence that we looked at was observational. So this is taking a large number of patients and asking them how much exercise do you do. And what we found with that is that if patients reported doing at least two and a half hours of exercise per week, they have about a 30% reduced risk of developing cardiovascular disease.

So that's a pretty big number and that suggests that exercise is really beneficial. So just to make sure I got that right, you're saying that you did this big survey effectively and you saw that for patients who were doing two and a half hours or more exercise a week, there was actually a 30% reduction in cardiovascular disease. So a really big reduction. Yeah, so that's the first line of evidence showing that is really important.

And we also did a study showing that it's not too late to start exercising. So typically in an observational study, you ask the exercise question at one time point. And in a study looking at adult survivors of childhood cancers, we asked the questionnaire at two time points. And we found that in individuals that increase their exercise, even by just 30 minutes a week, they also reduce their risk of cardiovascular disease by about 20%. Are there any randomized controlled trials around this?

There are plenty of randomized trials around this. Tell us about it. Yeah. So we kind of span the continuum. So we've got trials looking at if exercise is beneficial before you start treatment, exercise during treatment, and then exercise after you finish treatment. And what we've shown is if you start exercising right before treatment,

so we call this a window of opportunity. So you've been diagnosed and depending on the cancer type, so for example, in prostate cancer, you have a four to six week window before you go in for surgery. And in that trial, we tested different doses of exercise. So what's the volume of exercise? And does that improve some of the surgical outcomes?

And exercise does improve, it helps you recover from surgery a little bit quicker. More recent one, we also looked at exercise during breast cancer treatment. And this was for women that were receiving chemotherapy. So again, that pretty toxic regimen that is challenging to get through. And with this study, we found that exercise during and right after treatment was really

important in offsetting some of the cardiovascular changes that happen during treatment. Now, I think quite a lot of people listening to this, either who've had cancer and are living as a survivor after that, or maybe undergoing treatment, you know, around the world and the listenership to this podcast, really, almost every country in the world is amazing. Maybe thinking, you know, my oncologist didn't tell me to exercise, you know, in fact, they told me to rest. Do you feel that in general, this advice of doing no exercise is still quite common or actually are you seeing that there's been a sort of a big shift?

Cause you're saying that 20 years ago, like, you know, nobody had this for years. This is very new research. Yeah, I think at least in the seven years that I've been in the fields, there's been a shift. So I think it's much more common to say, recommend exercise, or there is less of an inclination

to recommend don't do anything. I think at least 50%, there was a recent survey that said at least 50% of oncologists recommended exercise training in the United States. So that's a pretty big shift. It's a big shift. But not yet, it sounds like you are hoping

that it's going to end up at a higher number than 50%. Yeah, exactly. And again, it's very different in countries around the world. So in Denmark and Norway, it's standard that if you receive a diagnosis, you can get an exercise program or go to an exercise center. Is that right? So there it's completely the norm.

So you really see a difference from country to country today. It's completely different. And that's where we're trying to get in the United States is that similar. And we just need the evidence showing that exercise is beneficial. I think the natural next thing I wanna ask

is you've used the word exercise a lot. And I'd like to understand what that means because I feel that whenever I speak to scientists, like what they mean by exercise can mean something very different from what most people listening to this is, which is going, that sounds like going to the gym or going for a run. Is that what you mean?

A lot of our programs are walking because it targets so many systems. Walking is great for your bones, for your muscle, for your heart. So it's a great way to target as many systems as you can at one time, a bigger bang for your buck. But there are certain patients who have low muscle. So there's certain types of chemotherapy or certain history

where you're starting out with not as much muscle mass as you might need. And that's where it's important to try and incorporate some of that resistance training. A lot of the work can be done depending on the level that you start with is with bodyweight exercise. So a lot of it is doing standing up and sitting down in a chair. That is a squat. And then as you get a little bit stronger, you can add

some resistance bands. So these are the stretchy bands that add a little bit of resistance. And the goal is to gradually build up your muscle size and your muscle strength. So that all sounds a lot less scary in a way than the resistance training. So I feel there's some branding to be done here. That's probably true, yeah. So that's really interesting. You're saying even that this really makes a difference to these side effects? 100%.

It's all about starting slow and continuing on and building. So imagine that we have two people. One is maybe a 60-year-old woman with breast cancer and another is maybe a 25 year old man with testicular cancer. And they both have sort of the, an average level of fitness for, you know, their age.

How might, you know, just to make that practical understanding, how might their recommended exercise program differ if at all? Yeah, I think the overall program would not differ that much between the two. I think their prescribed doses of exercise may differ. So the 60 year old woman with breast cancer may start at a lower level of exercise, for example.

She may start with just doing a 20 minute bout of walking exercise and then start with 60 minutes a week of exercise and gradually try to build up from there. Whereas the younger testicular cancer individual, he may want to do start a little bit longer. So he may have a little bit higher capacity and he may be interested in doing resistance training at the same time. So again, it's trying to tailor the exercise program to the different levels and the different interests. And this is about being realistic about where you are

rather than like having some, you know, which I think is often what scares people about exercise, right, is this theoretical idea of this amazing activity you can do, whereas you're just saying, start where you are and then you can move a little bit and it makes a big difference. Exactly, that's the key, is look at your levels, where you're at, what are you doing previously

and start there and try and build up. Should your exercise program start the second that you get this diagnosis? Should it be changing after treatment versus during treatment? What's the, how do you think about that? That's a really interesting question as well of because patients are receiving

this very tough treatment, should they wait and then start exercise after they've gone through a couple of cycles, or should they exercise during and after? And we just finished a trial looking at that exact question. And what we found was that for women receiving chemotherapy for breast cancer, exercising during and after chemotherapy, so a total of about 32 weeks, that was associated with the greatest improvements

in overall health, both in terms of how patients reported feeling, so less fatigue, less side effects from themselves, and then what we measured physiologically, it was better to exercise during and after. So basically start as soon as you can and then keep going. So in many ways I feel like this advice is quite similar to when you just talk about exercise in terms of health for somebody who's not living with cancer or some other disease, which is the best time to start is today

and the best time to stop is never. And is that, um, that's what you're actually seeing even when you're dealing with like these horrible treatments or, you know, recovery is, is it in a sense, as simple as that, Jessica? Yeah, it's, that's what we've seen is, you know, it's never too late to start. It's, it's just, you know, try and get out for a five minute walk. It's that movement that is really beneficial. I think that is fascinating because we've discussed on, on other shows, this idea that I've certainly been brought up to believe that, you know, when your parents get to a certain age, then suddenly like you should take their bags away from them and make them rest and not do anything very good.

And I've been told by various scientists, oh, well, actually the best thing you could do is probably give them your bag to carry up the stairs if you really want them to live to 90. Now I understand that here you're not as extreme as that and needs to be within the constraint of what you're able to do. But fundamentally you're saying even in this, you know, really quite extreme situation, actually if there is the capacity to do some more. And when you say exercise this, you know, again, this is sort of walking around. Amazingly, actually, that can be helping you, you know, is remarkable and shows, I guess, like this big swing away from I think a lot of the advice that we live

through in the 20th century. Exactly. That's all for this week's recap episode. If you want to learn 10 science-backed tips to improve your health for some of this podcast's most popular episodes, you're in luck. You can download it from zoe.com slash free guide. Or if you're looking for another episode to listen to today, why not try a popular episode of Zoey Science and Nutrition like what to eat to avoid osteoporosis, how to prevent heart disease, or mushrooms as medicine. Search for them on your favorite podcast player.