Regimens: Benefits of Not Staying Sedentary

By ERIC NAGOURNEY

new study may offer insight into the reasons that older women who exercise appear to have a lower risk of breast cancer.

Researchers from the Fred Hutchinson Cancer Research Center in Seattle say they have found that in postmenopausal women, regular exercise seems to lower levels of estrogen in the blood.

Advertisement

Older women with high levels of estrogen are more likely to develop breast cancer, said the researchers, who presented their findings this month at the International Cancer Congress in Oslo.

The lead investigator, Dr. Anne McTiernan, and her colleagues based their findings on a study of 173 women, ages 50 to 75, described as sedentary and overweight.

The women were divided into two groups. One took part in weekly stretch classes for a year. The other exercised for 45 minutes to an hour, five days a week, in the same period. Those women worked out two days at home and three days at a health center, where they were monitored.

After three months, the researchers found that blood estrogen levels of the women who were exercising had dropped an average of 4 percent. The estrogen of those who were stretching increased 3 percent on average. At the end of the year, the study reported, the differences remained, although they were not as pronounced.

The exercise appears central, the researchers said, because the women were not asked to change their diets. Some members of the stretch group lost weight, but their estrogen levels did not drop. On the other hand, the study found that some women who worked out maintained their weight and hormone levels.