WASHINGTON - Virtually all women are at risk of heart disease and doctors should more strongly consider prescribing a daily aspirin for their female patients, the American Heart Association said in new guidelines released on Monday.

The new guidelines greatly boost the recommended amount of exercise to at least an hour on most days of the week. They say women should be counseled more strongly to lose weight, eat more fresh vegetables, eat less fat and to quit smoking, according to the new guidelines.

"Nearly all women are at risk for cardiovascular disease, underscoring the importance of a heart-healthy lifestyle in everyone," Dr. Lori Mosca of the New York-Presbyterian Hospital and colleagues wrote in their report in the guidelines, published in the journal Circulation.

"Since the last guidelines were developed, more definitive clinical trials became available to suggest that health care providers should consider aspirin in women to prevent stroke," Mosca said in a statement.

"We have more aggressive recommendations for high-risk women, and strongly emphasize lifestyle strategies to reduce risk in all women," she added.

The new guidelines recommend that women change their eating and exercise habits to control blood pressure. They also recommend that:

-- Women should not only quit smoking but should use counseling, nicotine replacement or other forms of smoking cessation therapy.

-- Women should exercise at least 60 to 90 minutes on most, and preferably all, days of the week, at levels equivalent to brisk walking.

-- Women should lower saturated fat intake to less than seven percent of calories.

-- Women should eat oily fish or some other source of omega-3 fatty acids at least twice a week

-- Hormone replacement therapy and selective estrogen receptor modulators such as the osteoporosis drug raloxifene are not recommended to prevent heart disease in women.

-- Supplements such as vitamin E, C, folic acid and beta-carotene do not prevent heart disease and should not be taken to prevent it. "The new guidelines reinforce that unregulated dietary supplements are not a method proven to prevent heart disease," Mosca said.

-- Routine low dose aspirin therapy may be considered in women age 65 or older regardless of heart risk.

-- Women with a very high risk of heart disease should aim to lower their LDL (low density lipoprotein or "bad" cholesterol) to less than 70 mg/dL.

Heart disease is the largest single cause of death among women, accounting for 38 percent of all female deaths.

In the United States 42.1 million or just over one-third of all women have heart disease.