The Journal: International Journal of Cancer (online)

The Study:  Physical activity does not appear to lower a woman’s risk of colon cancer.

Because exercise has been shown to improve immune system function as well as speed the time it takes for food to move through the gastrointestinal track, experts have theorized that it might also inhibit colon cancer. More than forty studies have looked for evidence of this relationship. And though most of the data supports the link in men, for women the conclusions have been mixed.

A new study by researchers from the National Cancer Institute, the University of California-San Francisco and the University of Wisconsin-Madison collected information about physical activity and colon cancer cases for 31,783 post-menopausal women. During the ten-year study period from 1989 to 1998 there were 243 cases of colon cancer in the study group.  The researchers concluded that “our results do not support the hypothesis that physical activity confers significant protection against the overall development of colon cancer in women.” The authors noted, however, that better measures of total physical activity might have revealed such a link. Bottom line: “Our findings point towards the need for conducting further research.”

What it Means: First and foremost, the benefits of exercise in all areas of health and well-being clearly outweigh any doubts when it comes to its effect on any specific illness. So by all means keep up the physical activity. And in general, the more the better. But when it comes to preventing colon cancer, the third most common cancer among both women and men, the best course is regular checkups as well as colonoscopies after age 50 (and possibly earlier for African-American men and individuals with a family history of the disease). For some individuals, low-dose aspirin or another non-steroidal anti-inflammatory medication such as Advil or Motrin might also be recommended.

From the Magazine:
05/20/2005 Exercise to Slow Colon Cancer
12/15/2003 An Easier Colon Test
05/13/2000 Katie's Crusade