Physical activity lowers the risk of breast cancer

People who lead a healthy lifestyle and exercise regularly have not only a lower risk of cardiovascular disease but also a lower risk of cancer. A new study published in Cancer Epidemiology, Biomarkers, and Prevention and conducted by the American Cancer Society researchers confirms the hypothesis that sustained physical activity is important in cancer prevention. The study showed that moderate recreational activity resulted in decreased risk of breast cancer in postmenopausal women by 14%, while high physical activity decreased the risk of breast cancer by 25%.

There have been many studies conducted so far that have shown that women who have regular physical activity have a risk of about 25% lower for developing breast cancer compared to women who are inactive. However, it is unclear whether moderate physical activity such as walking has any benefit or if only intense exercise help prevent breast cancer. Also, it is unclear whether there is any association between tumor type (hormone receptor status) and individual factors such as BMI, weight status and hormonal therapies. Although there were many studies regarding the association between the risk of cancer and long periods of inactivity, though the link between sitting time and risk of cancer in postmenopausal women is unclear.

Therefore, the American Cancer Society researchers led by Alpa Patel, Ph.D. developed a study in which they compared the relationship between physical activity and breast cancer risk in postmenopausal women. Of the initial 73 615 postmenopausal women included in the trial, 4760 were diagnosed with breast cancer over the 17 years of study.

It was shown that a woman of 10 did not do any recreational physical activity at the beginning of the study. Among women who were active, the average time dedicated to physical activity was 3.5 hours per week. Physically active women’s favorite activities were walking, cycling, aerobics, dancing, so activities that involved moderate physical effort. Almost half of the women said they preferred walking as recreational physical activity. It was also discovered that physically active women were more likely to lose or maintain weight, more likely to drink alcohol and less likely to smoke. The study also showed that physically active women were more likely to use hormone therapy or to perform a mammogram in the past year.

According to the study, the most active women had a 25% lower risk of developing breast cancer than the least active women. It is important to note that this association did not differ by BMI, weight status, use of hormones or hormone receptor status. “Our results clearly support an association between physical activity and postmenopausal breast cancer, with more vigorous activity having a stronger effect,” Dr. Patel explained.