By Lisa Ellis
InteliHealth News Service

CHICAGO — In one of the first controlled clinical studies of the popular Atkins diet, people following this low-carbohydrate diet lost more weight than people on a standard low-fat, high-carbohydrate diet.

The Atkins group also experienced an increase in HDL — high-density lipoproteins, or the so-called "good cholesterol" — and a sharp drop in triglycerides, another form of blood fat, said lead researcher Eric C. Westman, M.D., of Duke University. He reported the results at the American Heart Association's annual Scientific Sessions.

These results, which will be published in the Nov. 21, 2002, issue of The Lancet, a British medical journal, show that the Atkins diet deserves more research, Dr. Westman said.

The study was funded by the Robert C. Atkins Foundation, whose founder invented the diet.

The diet's popularity for many years attests that many people have lost weight on it. But many nutrition experts and groups such as the American Heart Association (AHA) have questioned whether the results can be sustained long-term and whether it provides adequate nutrition, especially from fruits and vegetables.

Yet the diet has been little studied by independent academic centers. This is the third small study that follows a randomized, controlled design, considered the most scientifically reliable way to test a diet. The U.S. government's National Institutes of Health (NIH) recently provided funding for a larger study.

In the Duke Study, participants were obese people assigned at random to one of the two diets. Researchers made sure that the two groups were similar in important characteristics such as age and weight.

Among the 120 participants, the average age was 46 and the average weight was 211 pounds, Dr. Westman said. About three-quarters were female, and eight out of 10 were white.

Half of the participants were placed on a diet modeled after Atkins, with 10 percent of calories from carbohydrates, 30 percent from protein and 60 percent from fat. They also were given supplements, including fish oil and flaxseed oil, as recommended by the Atkins organization, Dr. Westman said.

The other group followed a low-calorie diet modeled after the NIH’s Step by Step program, Dr. Westman said. About half of the calories came from carbohydrates, 20 percent from protein and 30 percent from fat.

After three months, researchers found that 75 percent of those in the Atkins-type diet had stuck with it, compared with 57 percent in the high-carbohydrate group. The average member of the Atkins group had lost about 14 percent of body weight, compared with 9 percent for the other group, the study says.

The effects on cholesterol and other blood fats were mixed for the two groups.

Triglycerides dropped by nearly half in the Atkins group, more than double the reduction in the high-carbohydrate group. HDL increased 11 percent, compared with a 2-percent drop for the traditional diet. LDL, or low-density lipoprotein, known as "bad cholesterol," dropped 4 percent for the high-carb diet and increased 1 percent for the Atkins group.

But researchers also looked at some less widely used measures of blood fats that some studies suggest may make a difference in health.

They found that very low-density lipoprotein (VLDL), which may be more dangerous than LDL to heart health, dropped by half in the Atkins group, compared with 17 percent for the high-carbohydrate group.

They also found that among Atkins participants the more than half of the regular LDL consisted of large particles, which are considered less dangerous than smaller particles. The high-carbohydrate group’s LDL contained only 2 percent large particles.

The AHA continues to recommend a low-fat, high-carbohydrate diet for health and weight loss. But Robert Bonow, M.D., president, said the organization will continue to evaluate the issue as more information is available.

"Now that our top academic centers are starting to look at this, I think it's wonderful," Dr. Bonow said. "We just need more data."

He emphasized that diet is only one component in the prevention of heart disease. Exercise also is important, he noted. "The true recommendation is a healthy lifestyle."