Recent research shows a relationship between informal exercise and a lower risk for 13 kinds of cancer.
CAN LEISURE-TIME EXERCISE LOWER CANCER RISK?
THE GOOD NEWS
A new study shows that, in addition to its other health benefits, exercise seems to significantly reduce the risk of developing 13 different types of cancer — far more than researchers originally thought might be the case. And that’s not all. This study also suggests that these cancer-fighting benefits seem to hold true even if you’re overweight.
LENGTH AND SIZE OF STUDY
National Cancer Institute (NCI) and the American Cancer Society pooled data on 1.44 million people, ages 19 to 98, from the United States and Europe, examining a broad range of cancers. Participants were followed for a median of 11 years, during which 187,000 new cases of cancer were recorded. Findings were based on self-reported, leisure-time physical activity surveys.
PHYSICAL ACTIVITIES DEFINED
These leisure-time activities were defined as informal exercises done at one’s own discretion to improve or maintain fitness or health. Examples include walking, running, swimming, biking and other moderate to vigorous activities. The median activity level was 150 minutes of moderate activity per week—the recommended minimum level of physical activity for the U.S. population.
Research findings confirmed earlier studies (also assessed by self-reported surveys) that had shown a connection between exercise and a lower risk of colon, breast, and endometrial (uterus lining) cancers. They also found a lower risk for 10 additional cancers—of the esophagus, liver, stomach, kidney, blood, bone marrow, head and neck, rectum, and bladder.
Happily, these findings held true even when the researchers factored in body mass. People who were overweight or obese but exercised had a much lower risk of developing most cancers than overweight people who didn’t exercise.
This was an observational study so it doesn’t directly prove that exercise reduces cancer risks, only that there is a measurable association between more exercise and less disease. It also relied on participant memories, which can be unreliable.
Still, the findings really do suggest that moderate exercise can help to reduce the risk of many types of cancer.
For more information:
• nytimes.com - exercise tied to lower risk of cancer
• nih.gov - increased physical activity associated with lower risk of cancer