Exercising cuts risk of invasive cancers for older women

Get up and get moving. That's the recommendation for older women to lower their risk of cancer, from San Diego State University researchers.

Post-menopausal women who on a daily basis, had moderate to vigorous physical activity showed a 34% lower risk of certain cancers than those who were less active, cancer epidemiologists reported in a study.

Previous research has shown physical activity is related to the occurrence of 13 invasive cancers, but those studies relied on self-reported assessments of activity. The new longitudinal OPACH (objective physical activity and cardiovascular health) study, which is a part of the Women's Health Initiative (WHI), used accelerometers that the women wore on their hips for a week, which offer more accurate measurements of how active they were. Researchers then tracked the impact on their health for close to five years.

Of the 6,382 women aged 63 to 99 years who were part of the study, 272 women were diagnosed with one of 13 site-specific invasive cancers. Breast cancer was the most common, followed by lung cancer and colorectal cancer. But the incidence of cancer was lower among women who had an average of 80 minutes per day of moderate to vigorous physical activity, compared to those who had less than 20 minutes a day.

The 13 cancers associated with physical activity include breast, lung, colorectal, esophageal, liver, kidney, gastric, endometrial, leukemia, multiple myeloma, head and neck, rectal, and bladder cancers.

Women in the study cohort did develop other cancers—there were nearly 1,200 women diagnosed in total. But researchers from SDSU and the University of California, San Diego focused on the cancers related to being physically active in the WHI ancillary study that used OPACH data, which was published March 5 in the British Journal of Cancer.

The more the better

"We were interested in cancer risk," said Humberto Parada, first author and assistant professor in SDSU's School of Public Health. "We broke it up by the amount and type of physical activity as captured by the accelerometer, which ranged from lighter activity such as household chores, to walking and gym exercise on the moderate to vigorous side."

Parada and co-author Emily McDonald, a former graduate student, analyzed data from the OPACH study in which the women were instructed to wear the accelerometer for one week in 2012-13. They were then followed for 4.7 years with an annual questionnaire which tracked their health and disease incidence.

"These findings show that physical activity helps prevent cancer, and the more you do, the better it is," Parada said. "This can help inform and tailor the health guidelines for older, post-menopausal women."