American Heart Association Not Revising Dietary Guidelines After Study on Atkins Diet (dateline December 4, 2002)
A recent study presented at a meeting of the American Heart Association found that the so-called Atkins diet of high-protein, low-carbohydrate foods helped study participants lose more weight than a traditional low-fat diet. Participants on the Atkins diet also experienced a drop in cholesterol and triglycerides, high levels of which are risk factors for heart disease. Because of confusion that the American Heart Association might be endorsing the Atkins diet, the organization has issued a statement on its position and a sharp criticism of the study results, which it says were derived from a small study size and a short follow-up period.
The study was conducted by Dr. Eric Westman of Duke University and included 120 participants who were assigned to either follow a low-fat diet (not one specifically endorsed by the American Heart Association) or a high-protein, low-carbohydrate ("Atkins") diet, created by author Robert Atkins, which allows for substantial amounts of meat and fat. The low-fat diet consisted of an abundance of whole grains, fruits, and vegetables. The participants who followed the Atkins diet also consumed omega-3 fatty acids found in foods such as flaxseed and fish oil, which can lower the risk of heart disease and stroke.
The study results found that participants on the Atkins diet lost approximately 31 pounds, compared with an average of 20 pounds lost on the low-fat diet. Because the results were presented at an American Heart Association-sponsored meeting, the organization worries that the public will think it endorses the Atkins high-protein, low-carbohydrate diet, which is not the case.
In fact, the American Heart Association cited the following criticisms of the study:
- Small study size (only 120 participants, 60 of whom were on the Atkins diet)
- Short follow-up (participants were only followed for six months, not long enough to determine whether they can maintain weight loss)
- Lack of long-term evidence of health benefits (no evidence that the Atkins diet improves health for long periods of time)
- Saturated fat increases long-term heart disease risk (the current study did not provide long term follow-up to adequately evaluate heart disease risk)
- Current study did not compare the Atkins diet with the American Heart Associations dietary recommendations
The American Heart Association does not plan to change its dietary guidelines based on the study results. According to the organizations president, Robert O. Bonow, MD, "The current [American Heart Association] guidelines, based on the best available evidence, emphasize a healthy dietary pattern rich in fruits, vegetables, whole grains, lean meats, fish and poultry, as well as low-fat dairy products.
"Bottom line, the American Heart Association says that people who want to lose weight and keep it off need to make lifestyle changes for the long term this means regular exercise and a balanced diet," said Dr. Bonow. "People should not change their eating patterns based on one very small, short-term study. Instead, we hope that the public will continue to rely on the guidance of organizations such as the American Heart Association which look at all the very best evidence before formulating recommendations."