Even light daily physical activity lowers cancer risk

Recent research has linked daily physical activity—including physical activity of light intensity—with a lowered risk of cancer.

In a prospective cohort study of more than 85,000 adults in the UK, researchers at the National Institutes of Health (NIH) and University of Oxford found people who engaged in light- and moderate-to-vigorous-intensity daily physical activity had a lower risk of cancer than those who were more sedentary.

The findings, published March 26 in British Journal of Sports Medicine, are among the first to evaluate the cancer risk reduction associated with light-intensity activities such as running errands and performing household chores, notes an NIH press release.

Previous studies have shown an association between physical activity and decreased cancer risk, but most of these studies relied on self-reported questionnaires, which may not accurately capture the intensity of different activities. Earlier studies that used objective measures were focused on higher-intensity physical activity.

How the study worked

In the new study, led by researchers from NIH’s National Cancer Institute, participants in the UK Biobank study (who had a median age of 63) wore devices that tracked total daily activity, activity intensity and daily step count over a one-week period. The researchers then looked at the relationship between the daily averages and the incidence of 13 cancer types, including breast and colorectal cancer.

Then they followed up with study subjects years later. After a mean follow-up of 5.8 years, 2,633 participants had been diagnosed with one of the 13 cancer types. The people with the highest total amount of daily physical activity had a 26% lower risk of developing cancer than individuals who had the lowest amount of daily physical activity.

The researchers also explored the impact of replacing daily sedentary time with light- and moderate-to-vigorous-intensity physical activity and found that this shift was associated with a reduced risk of cancer. The associations between physical activity and cancer risk remained even after researchers adjusted for demographic factors, lifestyle factors, body mass index (BMI) and other health conditions.

Keep on stepping

Higher daily step count, but not the pace of the steps (step intensity), was also associated with a lower risk of cancer. Compared with cancer risk in those taking 5,000 steps per day, cancer risk was 11% lower for those taking 7,000 steps per day and 16% lower for those taking 9,000 steps per day. Beyond 9,000 steps, the risk reduction plateaued.

The researchers suggested that less physically active individuals may lower their cancer risk by incorporating more walking, at any pace, into their daily routine.

About the National Cancer Institute (NCI)

NCI leads the National Cancer Program and NIH’s efforts to dramatically reduce the prevalence of cancer and improve the lives of people with cancer. NCI supports a wide range of cancer research and training extramurally through grants and contracts. NCI’s intramural research program conducts innovative, transdisciplinary basic, translational, clinical and epidemiological research on the causes of cancer, avenues for prevention, risk prediction, early detection and treatment, including research at the NIH Clinical Center—the world’s largest research hospital. Learn more about the intramural research done in NCI’s Division of Cancer Epidemiology and Genetics. For more information about cancer, please visit the NCI website at cancer.gov or call NCI’s Cancer Information Service, at 800-4-CANCER (800-422-6237).

About the National Institutes of Health (NIH)

NIH, the US’s medical research agency, includes 27 Institutes and centers and is a component of the US Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical and translational medical research, and is investigating the causes, treatments and cures for both common and rare diseases. For more information about NIH and its programs, visit nih.gov.