YES. It absolutely does.
While there are billions of dollars spent each year around the world to discover better treatments and possible cures for various cancers, physicians like myself have known for a decade that there is scientific evidence that cancers can be prevented. And now, the evidence that exercise alone prevents many cancers is indisputable. So, why is there not a lot being said about this? Good question….
A large summary of individual studies that examined the relationship between exercise and cancer prevention has just been published. Cancers of the bladder, breast, colon, uterine lining, esophagus, stomach and kidney were ALL reduced 10-20% with exercise alone based on the 2018 Physical Activity Guidelines for Americans:
“ For substantial health benefits, adults should do at least 150 minutes (2 hours and 30 minutes) to 300 minutes (5 hours) a week of moderate-intensity, or 75 minutes (1 hour and 15 minutes) to 150 minutes (2 hours and 30 minutes) a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity. Preferably, aerobic activity should be spread throughout the week. Additional health benefits are gained by engaging in physical activity beyond the equivalent of 300 minutes (5 hours) of moderate-intensity physical activity a week. Adults should also do muscle-strengthening activities of moderate or greater intensity and that involve all major muscle groups on 2 or more days a week, as these activities provide additional health benefits.”
This large review of physical activity and cancer prevention also showed that exercise reduced lung cancer rates but only for those who were never smokers. Furthermore, cancers of the blood, brain, pancreas, ovary, prostate and thyroid were unfortunately not reduced by good exercise habits.
Although we do not exactly know the mechanism whereby exercise prevents cancer, it is clear that the protection extends to both men and women at virtually all ages.
Finally, exercise extends life expectancy in those who do contract breast or colorectal cancer. The association between physical activity and improved survival after one of these cancers is diagnosed is pretty impressive and approaches the effect of many conventional cancer treatments such as chemotherapy.
In summary, there is a very strong case to be made for exercise. Not only does it reduce death from stroke and heart attack, but it reduces risk of contracting many cancers. There is no drug, vaccine, diet, supplement or screening test that is as powerful at extending lifespan and preventing disease as exercise. And, its FREE.