Can exercise help prevent prostate cancer?

In recent years, one of the most provocative questions in cancer research has been whether regular exercise can prevent certain types of cancer from emerging.

The answer, as with any question related to cancer, is complicated. But a recent study published in The British Journal of Sports Medicine offered a glimpse into how regular physical activity affects the risk of prostate cancer, the second most common and second most deadly cancer in the United States for men.

In one of the largest efforts to date, researchers collected data from 57,652 Swedish men between 1982 and 2019 who had taken part in at least two fitness tests to see whether those who were more active were less likely to develop cancer. About 1 percent were later diagnosed with prostate cancer. The team found that those who had improved their fitness over the years were 35 percent less likely to develop the disease.

The finding is consistent with much of the latest research on the relationship between fitness and cancer diagnosis. According to a 2021 studyFor example, if all adults in the United States met physical activity guidelines, cancer diagnoses could drop by 3 percent, or 46,000 cases, each year.

But while there has been extensive research into the relationship between exercise and conditions such as breast cancer, less research has been done specifically on prostate cancer. The risk of prostate cancer increases for all men after the age of fifty; The risk appears to run in families. According to the American Cancer Society, approximately one in eight men will be diagnosed with prostate cancer during their lifetime.

Some previous research on the link between physical activity and prostate cancer has been conflicting, said study co-author Dr. Kate Bolam. While some showed it increased risk of prostate cancer for those who were physically active, others found a reduced risk.

But many of those studies had small sample sizes or focused on healthier people, said Dr. Bolam, a researcher at the Swedish School of Sports and Health Sciences.

“Men who are generally more health conscious,” she said, “are also good at going to the doctor when called for a prostate cancer screening.”

More testing means more diagnoses, even in men whose cancer will never progress. Sometimes cancer cells can persist in the prostate for a person's entire life and are not dangerous. Many men who are not tested and experience no symptoms may never know they have prostate cancer.

The Swedish team was able to create a more nuanced picture by using a national database of hundreds of thousands of laboratory results, including fitness tests that measure how well the heart and lungs deliver oxygen to the muscles.

Unlike studies that required patients to report their exercise habits, this provided experts with objective measurements. The results clearly showed a link between physical activity and a reduced risk of prostate cancer. It also showed that greater improvements in fitness were associated with greater reductions in risk.

This contributes to a growing understanding of how important exercise is for cancer prevention in general. An evaluation in 2019 by the American College of Sports Medicine found that regular physical activity significantly reduced the risk of bladder, breast, colon, endometrial, esophageal adenocarcinoma, kidney and stomach cancer. The same analysis also found that having a regular exercise habit was linked to better treatment outcomes and an increase in life expectancy for those already living with cancer.

While it's not clear exactly how this happens, experts said one explanation could be that exercise helps fight cancer by improving its function targets of the immune system and eradicates cancer cells.

“We know that even a single exercise helps our bodies release immune cells into our bloodstream,” said Neil M. Iyengar, a medical oncologist and physician-scientist at Memorial Sloan Kettering Cancer Center in New York City, who was not involved in the study. was involved. “It also helps to improve the population of immune cells in our tissues that fight cancer cells.”

He added: “In someone who exercises, you see more immune cells that are actually able to kill cancer cells. Whereas in someone who is more sedentary, especially someone who is obese, you see the opposite.”

Researchers don't yet know exactly the right dose and type of exercise that might be most effective, but both the American Cancer Society and the American Society of Clinical Oncology recommend 150 minutes per week, or 20 minutes per day, of aerobic exercise. This can include light walking, jogging or weight-bearing exercises.

Both Dr. Iyengar and Dr. Bolam recommended starting simple: find an activity that is fun and get moving. Think of playing with children or grandchildren, going for a walk or participating in a recreational sports competition. Consistency is key, they said, which is why it's important to find activity that doesn't feel like a chore.

“Everyone here has an opportunity to do something that is really cost-effective to reduce the risk of prostate cancer,” said Dr. Bolam. “And that is something that is completely within our control.”