Exercise and cancer

I am very passionate about phytonutrients and antioxidants and foods and lifestyle changes that help protect us from inflammation and chronic disease, among which cancer is a major one. We read and hear about the consumption of various super foods potentially preventing cancer all the time (as we should, especially as more and new data and research become available), but the role of exercise is less often discussed.

When we talk about exercise and its protective role in cancer, we mainly hear about it as helping keep us in a healthy weight range, which is important because being overweight is one of the predictors of cancer. But the role of exercise is independent of weight. It’s also independent of diet.

I read a copious amount of studies and summaries of studies (interestingly, more breast cancer articles popped up than any other specific cancer or even cancer as a whole, although I did find a few on colon, lung and gastrointestinal), and exercise is beneficial in preventing cancer as well as once diagnosed with cancer.

While studies varied in the intensity of the exercise, it does seem like more strenuous activity was most advantageous.

Most studies did not give or had inconsistent results across studies about a time-frame for optimal effect.

For breast cancer specifically, vigorous exercise affects the production of estrogen, making more intense exercise most effective. A study of Finns that was not specific to breast cancer, found that for breast cancer, an hour of moderate or intense exercise produces a greater risk reduction than those who have longer (2 ½ hours a week), more moderate sessions.  However, less intense exercise is indeed helpful as well. Several studies found that walking for more than 3 hours a week at an average pace had a lower rate of cancer recurrence and higher survival rates and  brisk walking decreased death rate over the next 6 years by 70%. The most active women had a 29% lower risk of breast cancer than those who exercised least. Survivors who worked for more than 2 ½ hours had a 67% lower risk of all deaths.

Overall, 30 min a day of even just walking proved to have protective effects.

It seems that we know that exercise helps prevent chronic inflammation, helps keep one’s weight in check, potentially changes the micro-environment of a tumor cell as well as provides anti-inflammatory signals that making it harder for cancerous tumors to grow, helps fight existing cancer as well as recurrence, helps improve cure and survival rates and helps with side effects from treatment, but we don’t know why or how “brisk exercise affects risk or why only some types of cancers are affected.

The bottom line seems to be simple: Move. Move more. The best protection against cancer, its recurrence and death from it, as far as exercise is concerned, is being active throughout your life in general and throughout all stages of diagnosis/the disease, if cancer is found.

randi morse, randi.morse@gmail.com, newton, ma