However, while the regimen skimped on bread and other carbohydrate foods, it was not the fatty Atkins diet that most people associate with the term "low-carb diet."

In a 20-year study involving over 82,000 women, the incidence of coronary heart disease was roughly equal for women who ate low- and high-carbohydrate diets, researchers reported in the Nov. 9 New England Journal of Medicine.

Heart risk was also 30 percent lower for participants who got their protein and fat from vegetables rather than from meat, they noted.

The Atkins diet, which became popular after its introduction in the 1970s, allows for unlimited intake of animal fat.

"I feel the take-home message of the investigation is that neither the low-fat or low-carbohydrate dietary pattern is ideal," said researcher Thomas L. Halton, who led the study while a doctoral student at the Harvard School of Public Health. "Both have strengths and weaknesses. However, you can get the best features of both diets and eliminate the negative features of both diets by choosing healthy vegetable sources of fat and protein."

The real goal is "taking steps to reduce the glycemic [fat] load of the diet by substituting lower glycemic fruits, vegetables and whole grains as well as vegetable sources of fat and protein for refined, high-glycemic carbohydrates," said Halton, who now teaches part-time at Simmons College in Boston

In the study, researchers tracked the health of more than 82,802 women in the Nurses Health study followed for 20 years, looking especially at the incidence of coronary heart disease. The women filled out questionnaires on their eating habits, and this information was used to calculate their percentage of energy intake from carbohydrate, fat and protein.

"The main message I walked away with is that a diet rich in vegetable protein and vegetable fat appears to have a benefit in lowering heart disease risk," said Susan Moores, a nutritional consultant in St. Paul, Minn., and a spokeswoman for the American Dietetic Association.

The women in the study reported "not what people think of as a low-carbohydrate diet, more of a moderate-carbohydrate diet," Moores said. "When you look at the amount of carbohydrates in the diets of women reporting the lowest levels, they were not eating a low-carbohydrate diet like the Atkins diet."

It's difficult to make specific recommendations based on the study because "there are so many qualifiers and questions about the diets the women actually ate," she said. "And it is hard to draw the conclusion that an Atkins-type diet affects the risk of heart disease."

But it was satisfying to see the benefits of eating plant-based fats and proteins laid out in the report, Moores said. "We have talked about it for years, and it is so nice to see it validated for a large group of women."