In Part 3 of this 4-part series, Janet Farrar Worthington talks with PCF-funded epidemiologist June Chan about what a healthy heart has to do with preventing or slowing down prostate cancer.
Exercise is the Turbo Boost to a Healthy Prostate
In the fight against prostate cancer, exercise is the gift that keeps on giving. But why? How does it work?
A sedentary life is not good for the heart. As we discussed in Part 2 of this series, diet is important, but it’s not the whole story here. The research team of June Chan, Sc.D., at UCSF has shown in multiple studies that exercise can help delay or prevent prostate cancer progression. “Aerobic exercise after prostate cancer diagnosis may reduce the risk of prostate cancer recurrence or death by up to 60 percent.” Chan’s earlier studies in this field, funded by PCF nearly a decade ago, showed a benefit to an hour of jogging six days a week – the level of exercise most of us can’t or don’t want to sustain. But don’t get discouraged! In more recent studies, she and colleagues have been looking at more doable levels of exercise – walking 30 minutes a day, or three or more hours a week, at a brisk pace (3 mph or faster). The brisk pace is important: One study found that men who walked three or more hours a week at a brisk pace after diagnosis had a 57 percent lower risk of having prostate cancer recur than men who walked at a slower pace, for less than three hours a week.
“Just walking, not running! Walking is so common. During these Covid times, when we’re confined to small spaces, people might find it difficult to walk the way they would prefer,” says Chan. “But I would say, just use it as a break to get fresh air – even if you’re just going up and down the same block. Any little bit of walking, as opposed to sitting. Movement is good for your overall bone health. Don’t push yourself to injury; just get in a good habit. It’s something you can do when you’re doing something else;” for example, “when I’m walking, often I’ll grab my phone, and use it as a chance to catch up with somebody.” Don’t focus on the number of steps, or the time. “If you’re always looking at your watch, you’re not enjoying the walk as much.” And don’t overdo it: “If you get injured, you might lose all interest in continuing.”
Note: the key here is giving the cardiovascular system a good workout, not necessarily the act of walking itself. So, apply this to your own needs: if walking that much is not a good option for you, swimming and riding an exercise bike – whatever you are able to do – are good, too. Studies by Chan and others have provided so much proof of the benefit of aerobic activity, in fact, that “we’re actually at the stage now that the updated Physical Activity Guidelines put out by the American College of Sports Medicine specifically note that exercise is recommended for men with prostate cancer to avoid the risk of dying from prostate cancer. We’re really excited that we got to contribute to that work.”
What is it about exercise? Chan and colleagues are still tapping the surface of all the ways exercise is good for the body. “It improves energy metabolism, lowers inflammation and oxidative stress, helps boost immunity, and is beneficial for androgen signaling pathways.” It is good for the heart and lungs, improves muscle strength and muscle mass, burns fat, lowers fatigue, anxiety, stress, and depression. “It just improves your overall quality of life,” says Chan. Bonus: exercise also may help slow down prostate cancer’s growth.
Chan is investigating the underlying biological mechanisms for “why exercise has these benefits for prostate cancer and overall health. Is it a systemic effect, or an anti-androgenic effect? Is it acting on oxidative stress pathways?” Her group is looking for insight from blood and tissue samples taken from men with prostate cancer before and after exercise interventions. In another large, phase 3 clinical trial funded by Movember, Chan and epidemiologists Stacey Kenfield and Lorelei Mucci, with principal investigators Rob Newton and Fred Saad are studying high-intensity exercise in men with metastatic prostate cancer at more than a dozen sites worldwide. “It’s a two-year, tailored intervention, with both strength and aerobic components,” to see if exercise can help men with metastatic prostate cancer live longer and better. What else lowers stress? Meditation. Stress may play a role in the growth of prostate cancer, so lowering stress is a strategy worth pursuing.
Speaking of strength training: We all lose muscle mass as we get older. Strength training (lifting weights or using resistance bands, and doing muscle-building exercises) fights this loss. Strength training can be especially helpful in men on androgen deprivation therapy (ADT) for advanced prostate cancer, who are at higher risk of loss of muscle mass, osteoporosis, and also of weight gain, metabolic syndrome, and diabetes. Note: If you have advanced prostate cancer, check with your doctor to make sure strength training is safe, and also for some guidance about the weights you should be lifting.
Final note on exercise: Start out slow. “If you have not exercised regularly for a long time, consult with a physician or personal trainer, to get a program tailored to fit you,” says Chan. “Start small, and go up by five- or ten-minute increments. Then see if you can pick up the intensity. Just make little changes.”
Look to the long haul: “Thank goodness I ate that broccoli on Thursday. Now I won’t get prostate cancer,” said no one ever. It’s not just one good food choice, but many years of erring on the side of healthy. The other side of that, however, is reassuring: It’s not just one bad food choice, or being a couch potato last weekend, but many years of not eating things that can help your body fight prostate cancer, many years of not exercising. “Diet is something you have to do every day,” says Chan. That said, “we’re all balancing so many things with food. Food is part of our culture, taste, our family habits, celebrations. I feel like the recommendations should just be like filters.” In other words: Many good decisions, over time, will help fight prostate cancer more than the occasional lapse will hurt it.
Check out the rest of this series here:
Coming soon: Part 4 – The Best of the Best: Food Science and Prostate Cancer