New study adds fuel to the Atkins fire
At a time when many dieters are shedding pounds by indulging in great plates of steaks, bacon, eggs and butter, even doctors are seeing some positives in the regimen that flies in the face of conventional nutritional wisdom. Trouble is, no one yet knows whether favoring fat over carbohydrates makes people healthier in the long run.
Dr. Eric C. Westman, an internist at Duke University, stepped into the lion’s den last week when he presented data to the American Heart Assn.’s annual scientific meeting showing that overweight people on the high-fat, low-carbohydrate plan lowered their triglycerides and boosted their good cholesterol while taking off more weight than those on a low-fat diet.
His results, while provocative, were hardly the last word in an ongoing debate fueled by the faddishly popular diet first proposed by Dr. Robert Atkins in the 1970s.
“We need to study it further,” said Westman, a staff physician at the Duke Diet and Fitness Center, whose findings have been submitted for publication and aren’t yet peer-reviewed. Westman’s research stemmed from his curiosity about a diet followed by many of his patients, family and friends. He asked the nonprofit Robert C. Atkins Foundation, created by the diet doctor, for funding.
In the meantime, the American Heart Assn. continues to advise avoiding saturated fats and basing meals on fruits, vegetables, lean meats, whole grains and low-fat dairy products.
Westman studied 120 overweight volunteers, half randomly assigned to follow the Atkins plan and take an Atkins dietary supplement consisting of fish oil, flaxseed oil and borage oil (all rich in heart-healthy Omega-3 fatty acids), and half assigned to a low-fat diet.
After six months, members of the low-carb group lost an average of 31 pounds, compared with 20 pounds for the low-fat group. The Atkins followers (only 36 of whom finished the study) had higher levels of good cholesterol, or high-density lipoprotein, or HDL, than the 27 who completed the low-fat diet.
The low-carb dieters also posted larger reductions in triglycerides--another blood fat linked to heart disease, and bigger reductions in levels of very low-density lipoprotein, or VLDL, part of bad cholesterol.
Critics noted that Westman studied only a small group of people, and that six months was too short a time to know whether the diet could improve health in the long term.
“What we don’t know is whether these lipid changes and the weight loss itself over the long term are going to continue to look as favorable,” said Dr. Ronald M. Krauss, director of atherosclerosis research at Children’s Hospital Oakland Research Institute.
Krauss said some of the improvements among the Atkins followers could be explained by known phenomena. For example, losing weight and limiting carbohydrates can lower triglycerides, and “when triglycerides go down, the HDL does tend to go up.” That response is “not specific to any particular diet,” Krauss said. He noted that paradoxically, HDL rises when you eat lots of saturated fat and cholesterol. “If you’re loading the body with cholesterol, HDL going up is a way of protecting against cholesterol.”
At the same meeting, researchers from the University of Washington in Seattle and University of Cincinnati presented results from a six-month study of low-fat and low-carb diets, in which the low-carb dieters lowered their levels of C-reactive protein, considered a better marker of heart disease risk than cholesterol, according to a study that appeared in the Nov. 14 New England Journal of Medicine.
For people inclined to try the Atkins plan, Krauss has a reminder: “Any diet that restricts food choices, particularly over the short term, is going to succeed, be it high-carb or low-carb.”
