Friday, February 18, 2000, 4:40 PM ET

NEW YORK, Feb 18 (Reuters Health) -- The extremely carbohydrate-restricted Atkins diet is a safe, effective way to lose weight, according to studies presented at the Southern Society of General Internal Medicine in New Orleans.

A study of the diet conducted at the Durham VA Medical Center in North Carolina showed that on average, mildly obese people lost about 21 pounds in four months on the diet, and had positive changes in heart risk factors such as reduced cholesterol and increased HDL or "good cholesterol."  These results are supported by a second study from researchers at the Atkins Center for Complementary Medicine in New York.

The Durham study included 41 mildly obese, healthy people who attended an outpatient clinic.  The study participants followed a program that reduced carbohydrate intake to less than 20 grams per day, and included vitamin supplements, fish oil supplements and 20 minutes of exercise at least three times per week.

Over four months on the diet, the participants lost an average of 21.3 pounds, and showed a 6.1% drop in cholesterol, and almost a 40% drop in the level of triglycerides in their blood.  In addition, their HDL levels increased by about 7%.  In a press release, the researchers also say that their study did not find any of the safety concerns voiced by the American Dietetic Association, such as potentially dangerous effects on liver and kidney function.

"In four short months on the Atkins Diet, we were able to confirm scientifically what Dr. Atkins states he has seen in his practice over the past decades.  The diet lowers cholesterol and triglycerides and raises HDL... which may represent an entirely new approach to the control and prevention of heart disease,'' said lead researcher Dr. Eric C. Westman, assistant professor of medicine at North Carolina's Duke University.

The study is continuing in order to assess the long-term effects of the diet.

Reporting the results of the second study, Colette Heimowitz, director of nutrition at the Atkins Center in New York, said that it was based on 319 overweight or obese patients treated at the Center for at least a year. Investigators collected information on weight, blood pressure, cholesterol, kidney and liver function and other parameters during the study.

"What we found is what we already knew from anecdotal data,'' Heimowitz told Reuters Health in an interview after the meeting on Friday.  "There were some pretty impressive benefits in body composition, HDL levels went up, LDL levels went down and blood pressure decreased,'' she reported.  Where HDL is the good cholesterol for its association with reduced heart risk, LDL has earned the name of being the "bad'' cholesterol because high levels are associated with heart disease.

"We now have data for the scientific community'' on the healthful benefits of the Atkins diet, Heimowitz asserted.

The Atkins diet severely restricts carbohydrate intake to induce a state of ketosis, or metabolic starvation. Dieters are encouraged to measure urinary ketone excretion as an indication of how effective the diet is in inducing fat breakdown.  ''Ketosis is a benign byproduct of fat burning,'' Heimowitz asserted. "With an adequate protein and fat intake, there is no loss of muscle mass... There is no change in (blood) pH if the diet is properly done,'' she said.

However the diet is not for everyone, Heimowitz warned. ''It's for those who need a correction in their sugar and carbohydrate metabolism...We encourage (vitamin) supplementation and an intake of 'good' fats, such as fish oil,'' Heimowitz commented.