August 31, 2005 Boston, MA --
The news as of late has been overwhelming that not only is regular exercise a great prescription for the prevention of disease, but the evidence points to regular exercise's ability to increase the survival rate of certain diseases.
In the most recent issue of JAMA, women with breast cancer who engaged in a moderate but consistent amount of physical activity had a better survival rate than those who don’t exercise.
Reduced Levels Of Circulating Ovarian Hormones
There is reason for the higher survival rate is the link between physical activity and lower levels of circulating ovarian hormones. Lower estrogen levels among physically active women with breast cancer could potentially improve survival, although few data exist to support this hypothesis.
Michelle D. Holmes, M.D., Dr.P.H., of Brigham and Women's Hospital and Harvard Medical School, Boston, and colleagues conducted a study to examine whether higher levels of physical activity after a breast cancer diagnosis would be associated with longer survival.
Physical Activity Measured in MET-hours per Week
The study was based on responses from 2,987 female registered nurses in the Nurses' Health Study who were diagnosed with stage I, II, or III breast cancer between 1984 and 1998 and who were followed up until death or June 2002, whichever came first. Physical activity was measured as metabolic equivalent task (
) hours. Three MET-hours is equivalent to walking at average pace of 2 to 2.9 mph for 1 hour.
Moderate amount appears to be optimal. The reduction rate peaks at 9-14.9 MET-hours per week as indicated in the below table:
|MET-Hours per week of physical activity
||Related Reduction In Death From Breast Cancer
|3 - 8.9
|9 - 14.9