Dr. Rob van Dam and colleagues at the Harvard School of Public Health and Brigham and Women's Hospital, both in Boston, recruited nearly 80,000 women age 34 to 59 in 1980 who were part of the Nurses' Health Study and tracked them for 24 years.

Over the follow-up period, the researchers documented 8,882 deaths including 1,790 from heart disease and 4,527 from cancer.

The study, published in the British Medical Journal, estimated 28 percent of these deaths could have been avoided if women had never smoked and that 55 percent could have been avoided if women had in combination never smoked, had regular physical activity, a healthy diet and maintained a healthy weight.

Alcohol intake did not substantially change this estimate although heavy alcohol consumption is linked to an increased risk of dying from cancer, van Dam said. However, women with light-to-moderate alcohol consumption -- one drink a day -- were less likely to die from cardiovascular diseases than alcohol abstainers.