The American Heart Association's announcement that the association will issue a position paper against high-protein, low-carbohydrate diets, such as the Atkins Diet, may have sidelined state-of-the-art science and has done nothing but further confuse the American public.
Dr. Robert Eckel, senior author of the paper, has made several misleading claims in the media, based on selective science and personal observations, about these diets.
Ironically, in the last few days, Dr. Robert C. Atkins presented at the American College of Cardiology as part of an ACC initiative to objectively and scientifically review several new viable options in the prevention and treatment of heart disease. This latest statement from the AHA is not in line with this new direction.
The following are the misrepresentations as reported by Dr. Eckel and rebuttals from Colette Heimowitz, M.S., director of education and research at Atkins Health and Medical Information Services, on behalf of Dr. Atkins.
Eckel: High-protein, low-carbohydrate diets put people at risk for heart disease. Long-term, the saturated fat and cholesterol content of the diet will raise the bad cholesterol and increase the risk for cardiovascular disease, particularly heart attacks. People who have lost weight and continue to maintain their weight on such diets will experience an increase in cholesterol levels because they continue to eat high amounts of saturated fat even though they are no longer losing weight.
Atkins: When people lose weight on the Atkins Diet, cholesterol goes down because the body switches from a sugar metabolism to a fat metabolism. As long as the person stays beneath their critical carbohydrate tolerance (the point at which the body no longer burns fat for fuel), cholesterol will not go up.(1) The only way cholesterol will rise on the Atkins program is if the dieter goes back to eating excessive carbohydrates, which is not recommended on the Atkins program. When an Atkins dieter reaches their goal weight and is on the maintenance plan, if their carbohydrate tolerance level allows them to take in a lot of carbohydrates without going to excess, then we recommend cutting back on saturated fats, and incorporating more monounsaturated fats such as olive oil, avocado, seeds and nuts, into the diet.
Eckel: People lose weight on high-protein, low-carbohydrate diets because they reduce calories.
Atkins: While it may be true that some Atkins dieters reduce calories, it is because the satiation effects of protein, fat and vegetables may decrease one's cravings for sugar and excess calories.(2) A recent study published in The Journal of Adolescent Health showed that those following a low-carbohydrate diet consume more calories (1830) than those on a low-fat diet (1100) and still continue to lose weight.
Furthermore, a review of historical and new research that Dr. Atkins presented before a very receptive audience at the ACC conference (March 20) confirms that elevated triglycerides and low HDL (high-density lipoproteins, the so-called "good cholesterol") may ultimately prove to be the most important risk factors in heart disease. This research review demonstrates how high carbohydrate intake is directly linked to elevated triglycerides and decreased HDL; while a low-carbohydrate diet can decrease triglycerides, increase HDL, and normalize the HDL/LDL ratio, potentially reducing or eliminating the need for pharmaceuticals and, in many cases, invasive therapy.(3)
In short, a diet that controls carbohydrate consumption correctly, as the Atkins Diet does, is not dangerous, in fact it is probably very beneficial to the heart as it reduces risk factors. A controlled-carbohydrate diet allows your body to burn fat rather than store it, lowering cholesterol. It is the combination of fat and carbohydrates that is dangerous, not fat on its own.
Next steps to resolve this controversy:
Experts from Atkins Health & Medical Information Services, along with a team of independent experts from major medical research facilities around the nation, are prepared to meet with the AHA to review current scientific research in the hopes of issuing a balanced and scientifically accurate report to the American public within the next few months.
References: The following are examples of scientific references in support of the aforementioned statements.
Volek JS et al.: Fasting lipoprotein and postprandial triacylglycerol responses to a low-carbohydrate diet supplemented with n-3 fatty acids. J Am Coll Nutr Jun; 19(3):383-391, 2000
Sondike S et al.: The ketogenic diet increases weight loss but not cardiovascular risk: A randomized controlled trial. J Adol Health 26: 91, 2000
Westman E et al.: Effect of a very low CHO diet and nutritional supplements on serum lipids in mildly overweight individuals. Abstract presentation at Southern Regional Society Genl Int Med. Feb. 18, 2000
Lean ME et al.: Weight loss with high and low carbohydrate 1200 kcal diets in free living women. Eur J Clin Nutr Apr;51(4): 243-8,1997
Willi SM et al. : The effects of a high-protein, low-fat ketogenic diet on adolescents with morbid obesity : body composition, blood chemistries, and sleep abnormalites. Pediatrics 101(1) : 61-7, 1998
Latner JD and Schwartz M: The effects of a high-carbohydrate, high-protein or balanced lunch upon later food intake and hunger ratings. Appetite 33(1):119-28,1999
Skov AR et al.: Randomized trial on protein vs. carbohydrate in ad libitum fat reduced diet for the treatment of obesity. Int J Obesity 23:528-36, 1999
Gaziano JM et al.: Fasting triglycerides, high-density lipoprotein, and risk of myocardial infarction. Circulation 96(8):2520-5, 1997
Austin MA et al.: Hypertriglyceridemia as a cardiovascular risk factor. Am J Cardiol 81(4A):7B-12B, 1998
Bieke B et al.: Treatment of hypertriglyceridemia by two diets rich either in unsaturated fatty acids or in carbohydrates: effects on lipoprotein subclasses, lipolytic enzymes, lipid transfer proteins, insulin and leptin. Int J Obesity 24(10):1286-96, 2000 60. Abbasi F et al.: High carbohydrate diets, triglyceride rich lipoproteins, and coronary heart disease risk. Am J Cardiol 85:45-8,2000
Stavenow L and Kjellstrom T: Influence of serum triglyceride levels on the risk for myocardial infarction in 12,510 middle aged males: interaction with serum cholesterol. Atherosclerosis 147:243-247,1999