CHICAGO (AP) _ Cholesterol-reducing drugs can help unclog women's coronary arteries and reduce the risk of heart attacks, just as the treatment does for men, a new study showed.

The study is the first to document the reversal of atherosclerosis in women through the use of the drugs, researchers said.

''Critics have pointed out that no previous studies have provided data on the response of atherosclerotic disease in women to (blood-cholesterol) lowering therapy,'' study author Dr. John P. Kane wrote in Wednesday's Journal of the American Medical Association.

Cholesterol kills by clogging the blood vessels that feed the heart with lesions - a combination of cholesterol deposits and scar tissue. Previous studies have shown that lowering blood cholesterol levels can reduce coronary artery lesions in men.

In their study over several years, authors looked at 41 women and 31 men with atherosclerosis.

Subjects took bile acid-binding resin and niacin daily, which along with dietary changes reduced their blood-cholesterol levels an average of 38.1 percent.

After 26 months, coronary artery lesions shrank just more than 2 percent among the 22 women enrolled in the treatment. Lesions diminished under the treatment program at about the same rate as they originally developed.

The 19 women in the control group, whose blood cholesterol levels were reduced about 10.6 percent through diet changes and less-intensive drug treatments, showed just more than a 1 percent increase in coronary artery lesions, the study said.

''There are lots of other risk factors besides cholesterol. But one of the most important risk factors is high cholesterol, and reversal of atherosclerosis can reduce the chances of a heart attack,'' said Dr. Mary Malloy, co-author of the study.

The treatment's effect on men in the study showed the same trends, but did not result in a statistically significant difference among men, the study concluded.

Kane is a professor of medicine and biochemistry at the University of California at San Francisco.

Earlier studies concentrated on men because coronary diseases occur much more frequently in males between 40 and 60 years old than in women, said Dr. David Blankenhorn of the University of Southern California.

Blankenhorn said doctors ''use the same medicines in women as in men, but they're less likely to prescribe (cholesterol-reducing) medicines in women, because the evidence wasn't in regarding what would happen.''

Women who haven't undergone menopause also get some protection because the level of estrogen in their bodies slows the formation of coronary artery lesions, Malloy said.

Because of the effects of estrogen, researchers have been slow to show that coronary artery lesions can be reduced in women, said one critic, University of Wisconsin nutritionist Laura Vailas.

''We do know regression of atherosclerosis can be shown in men, and I think we've been complacent in showing it in women. Women do suffer risks just as men do,'' Ms. Vailas said.