Heart experts remain cautious on Atkins diet

The American Heart Association denies that it is changing its policy toward high-protein diets and has repeated its belief that such weight-loss plans could be harmful.

Last week, a Duke University study report, presented at a meeting of the heart association, said that patients on the Atkins diet, a low-carbohydrate diet that allows unlimited meat and fat, lost weight and saw their cholesterol levels drop.

The researchers said the patients on the Atkins-based diet lost more weight than those on a low-fat diet.

Heart association president Dr Robert Bonow said the following publicity meant many people were under the false impression that his organisation endorsed the Atkins diet.

"We decided we had to come up with a new statement indicating what the nature of this study was," he said.

"It was one of 3600 papers presented at the meeting."

The association's statement said: "Media reports about a small study funded by the Robert C. Atkins Foundation may have created the erroneous impression that the American Heart Association has revised its dietary guidelines."

It added: "This is not the case."

The association in fact recommends a diet based on whole grains, with plenty of fresh fruit and vegetables and a small amount of lean meat and low-fat dairy products.

Dr Eric Westman studied 120 patients who followed either a low-fat diet - not the heart association's diet - or one advocated by bestselling diet book writer Robert Atkins.

Added to the Atkins-type diet were oils containing omega-3 fatty acids, which can help reduce heart disease and stroke risk. They included flaxseed, borage and fish oils.

Patients on the low-carbohydrate diet lost an average of 14kg during the study period, compared with an average 9kg weight loss in the low-fat diet group.

"We have concerns both about the study and in particular the diet itself," Dr Bonow said.

"People on that diet lost weight and their cholesterol and triglycerides went down.

"But any weight loss will lead to a lowering of cholesterol and triglycerides.

"As the weight stabilises, many times the cholesterol goes back up to where it started," he said.

Over a period of years, such a diet could be expected to raise cholesterol levels and increase the risk of heart and kidney disease, Dr Bonow said.

Cancer experts say it can also raise the risk of cancer.

A larger study that received little attention showed that women who ate plenty of fresh fruits and vegetables gained less weight as they aged than women who ate less.

Simin Liu and colleagues at Harvard Medical School followed 74,000 women for 12 years and found most of the women gained at least some weight as they aged.

But the more fruits and vegetables they ate, the less weight they gained.

"This is a much more compelling study regarding weight control, because it involved many more individuals over a much longer period," Dr Bonow said.

- REUTERS

Herald feature: Health