Thanks for reading Scientific American. Continue reading with a Scientific American subscription. Ornish goes to argue that protein and saturated fat increase the risk of mortality and chronic disease. 2002;75:848-855. Despite being told to eat less fat, he says, Americans have been doing the opposite: They have actually consumed 67 percent more added fat, 39 percent more sugar and 41 percent more meat in 2000 than they had in 1950 and 24.5 percent more calories than they had in 1970. Yes, Americans have been eating more fat, sugar and meat, but we have also been eating more vegetables and fruits (pdf)because we have been eating more of everything. CLAIMS THAT AN ATKINS DIET IS BETTER THAN A LOW-FAT DIET. Weight loss was 1 lb/week on the 10% fat diet and 0.6 lb/week on the Atkins diet. Question 12 options: his core , muscle memory, his progression , specificity training, Kim is conditioning. Only patients following the Atkins diet showed a worsening of each CVD risk factor (LDL-C, triglycerides, total cholesterol, HDL-C, total-to-HDL cholesterol ratio, homocysteine, Lp(a), and fibrinogen), despite achieving statistically significant weight loss. American Dietetic Association. A more healthful and evidence-based choice is to substitute simple carbohydrates with complex (unrefined) carbohydrates including whole foods such as fruits, vegetables, legumes (including soy products), and whole grains (such as brown rice and whole wheat flour). Effect of low-carbohydrate high-protein diets on acid-base balance, stone-forming propensity, and calcium metabolism. 1987;76:504-507. The Lifestyle Heart Trial. Randomized controlled clinical trials, although certainly not perfect, are better tools for chipping away at causality, and they suggest that protein and fat dont deserve to be demonized. 2002;76:535-540. Am J Physiol. Some scientists think so. I'm not aware of a single study showing that a diet high in red meat can reverse the progression of coronary heart disease. It was terribly misleading when this abstract made it appear as though the Atkins diet is better for your heart. At 12 months, secondary outcomes for the Atkins group were comparable with or more favorable than the other diet groups. Only total cholesterol and HDL changed in this study, so these were the only factors in determining the risk score. Atkins Nutritionals, Inc. 1972;56:359-364. The corresponding HRs (95 percent CIs) were 1.18 (1.131.23) and 1.21 (1.131.31) for CVD mortality and 1.10 (1.061.14) and 1.16 (1.091.23) for cancer mortality. SUBSTITUTE SIMPLE WITH COMPLEX CARBOHYDRATES. Bushinsky DA, Chabala JM, Gavrilov KL, Levi-Setti R. Effects of in vivo metabolic acidosis on midcortical bone ion composition. Part of the problem in this and other studies that compare weight loss in low-fat versus low-carb diets (which is the wrong question anyway, because its the type of fats and carbs) is that adherence to different diets is often suboptimal, so its hard to make meaningful comparisons. When you eat less fat, you consume fewer calories without having to eat less food, thereby increasing satiety without adding calories. The participants all had trouble adhering to their regimens, but all lost about the same statistically significant amounts of weight, and when compared head to head, the Atkins dieters saw greater improvements in blood pressure and HDL cholesterol than the Ornish dieters did. Robert Atkins debates Dean Ornish and John McDougall on whether a low-carb, high-protein diet is The decrease in the percentage of calories from fat during the period 1971 to 1991 is attributed to an increase in total calories consumed; absolute fat intake in grams actually increased. Available at: http://hin.nhlbi.nih.gov/atpiii/calculator.asp?usertype=prof . The editor of JAMA Internal Medicine invited me to write an accompanying editorial for this study. You start by eating 40 grams of net carbs, 4 to 6-ounce servings of protein and 2 to 4 servings of fat per day. Am J Clin Nutr. After one year those following his diet were more likely to see a regression in their atherosclerosis. We also published an analysis showing that improvements in dietary fat intake, exercise and stress management were individually, additively and interactively related to coronary risk. Taubes G. What if its all been a big fat lie? (Also: the heavy protein consumers in the study were consuming nearly 30 percent more protein than the average American does.) An Atkins diet may increase postprandial lipemia and increase free fatty acids, which may have harmful effects on platelet aggregation and may promote ventricular arrhythmias (57,58). National Institutes of Health. WebDr. But replacing animal protein with well-balanced plant proteins is beneficial, and this is in the mainstream of what most scientists who do nutrition research believe. Pereira MA, Jacobs DR Jr, Pins JJ, et al. In summary, decreases in HDL-C due to a low-fat diet have a very different prognostic significance than someone who cannot raise HDL-C as much on a high-fat diet. Updates? Losing weight is important, but the history of medicine is replete with examples of weight-loss approaches that were harmful to health (eg, amphetamines, fen-phen). Esselstyn CB Jr. Updating a 12-year experience with arrest and reversal therapy for coronary heart disease (an overdue requiem for palliative cardiology). Risk assessment tool for estimating 10-year risk of developing hard CHD (myocardial infarction and coronary death). This optimal diet is based predominantly on fruits, vegetables, grains, and legumes in their natural, unrefined forms. Reductions in total cholesterol, LDL-C, triglycerides, and total-to-HDL cholesterol ratios were significant only in patients who were following either a 10% fat diet or a 15% fat, calorie-controlled diet. Cambridge, MA: Harvard University Press; 1980. The rivalry between Atkins and Ornish was related to food intake. The other problem with Ornishs antiprotein stance is that he lumps all animal proteins together. Thus, dietary fat is not responsible for obesity. In fact, per capita consumption of fat has risen by 10 Ib/year since 1975, whereas per capita consumption of simple carbohydrates has increased even more, by 20 Ib/year (5). HDL is important only to the extent that it affects atherosclerosis and myocardial perfusion, it is not a disease. At Pennsylvania State University, researchers found that healthy women instinctively ate about 3 lb of food a day, whether high or low in calories. Because these foods are low in fiber, large quantities of calories can be consumed without feeling full. Goldstein JL, Brown MS. Cholesterol and cardiovascular disease. In his lengthy reply to my article Dean Ornish says I distort his beliefs, cite questionable studies and dont have the clinical experience to assess nutritional evidence. JAMA. In contrast, there was a statistically significant reduction in LDL-cholesterol in the Ornish group but not in the Atkins group after one year. 2007 Jul 11;298(2):178).This says something important about the quality of that research. Urinary excretions of calcium and acids are correlated positively with intakes of animal and nondairy animal protein but are correlated negatively with plant-protein intake (53). 1999;282:1539-1546. My colleagues and I have been training and certifying teams of health care professionals at leading hospitals, clinics and health systems in this lifestyle program for reversing heart disease. Diet was assessed by validated food frequency questionnaires and updated every four years. Again, we dont know because his studies have not been designed in a way that can tell us anything about the effect of his diet alone. Stout RW. I have presented these research findings on several occasions at the annual scientific meetings of the American Heart Association, American College of Cardiology, American Dietetic Association (now the Academy of Nutrition and Dietetics), the Institute of Medicine of the National Academies and many others. Liu S, Stampfer MJ, Hu FB, et al. If they stop eating bagels, they may also stop eating the cream cheese. JAMA. He began the Lifestyle Heart Trial, a controlled study of the effects of a low-fat diet and stress-management regime on a small group of heart disease patients, implementing a unique approach to treating heart disease that he developed in the late 1970s while he was still a student. Thus, neither an Atkins diet nor a 30% fat diet is very effective in lowering LDL-C or in maintaining long-term weight loss (25). 2002;113:30-36. Ornish D. The case for low fat. The title is confusing and potentially harmful to many readers. Whole foodssuch as whole grain products and fruits and veggiesare healthy, but I think that dairy products, fish and lean cuts of meat or poultry can also be part of a healthy diet, Steffen says. Ornish wrote several popular books, including Stress, Diet, and Your Heart (1982), Dr. Dean Ornishs Program for Reversing Heart Disease: The Only System Scientifically Proven to Reverse Heart Disease Without Drugs or Surgery (1990), The Spectrum: A Scientifically Proven Program to Feel Better, Live Longer, Lose Weight, and Gain Health (2007), and Undo It! J Am Coll Nutr. Telling people what they want to believe is part of the reason that the Atkins diet has become so popular. But even if the NHANES data are accurate, they show Americans are eating more fat than ever and even more refined carbohydrates than ever. Second, another big fat lie that has been repeated so often its becoming a meme is that there is not enough good science to inform us about an optimal way of eating. And the 10 percent reduction in carbohydrate in the higher protein diet and the higher unsaturated fat diet was achieved by replacing some fruits with vegetables, reducing sweets and using smaller portions of refined grain products. The case for a low-fat, highcarbohydrate diet. It found that individuals assigned to eat high-fat (41 percent calories from fat), Mediterranean-style diets for nearly five years were about 30 percent less likely to experience serious heart-related problems compared with individuals who were told to avoid fat. First, I cited several large-scale studies from many different investigators, all of which showed that a diet high in red meat increases the risk of premature death from virtually all causes, even when adjusting for confounding variables. Weight loss was not statistically different among the Zone, LEARN, and Ornish groups. Your body excretes toxic substances through your bowels, breath, and perspiration, so this is not surprising. And it is worth noting that among people in the study over 65, heavy consumption of animal protein actually protected against cancer and mortality. Her article begins with a gross distortion of what I believe. The Framingham risk score is calculated from age, sex, total cholesterol, HDL, smoking, and systolic blood pressure (46). Other high-protein diets such as the Zone and the South Beach diets are somewhat better but still emphasize consumption of meat, eggs, and butter. When people go on a high-protein diet, they may lose weight and lower triglycerides if, like most Americans, they had been eating a diet high in simple carbohydrates. What is Kim MOST trying to strengthen? Ornish then moved to the Boston area for a clinical fellowship at Harvard Medical School and an internship and residency in internal medicine at Massachusetts General Hospital, which he completed in 1984. Kennedy ET, Bowman SA, Powell R. Dietary-fat intake in the U.S. population. Dietschy JM, Brown MS. Effect of alterations of the specific activity of the intracellular acetyl CoA pool on apparent rates of hepatic cholesterogenesis. 1993;328:1213-1219. Its hard to move the science forward when there are so many stakeholders who say this is the right diet and no other one could possibly be right, Bazzano says. Twelve-month randomized trial conducted in the United States from February 2003 to October 2005 among 311 free-living, overweight/obese (body mass index, 27-40) nondiabetic, premenopausal women. 1990;322:1053-1059. Not exactly. Ornish was a physician consultant to U.S. Pres. Cognitive effects of ketogenic weight-reducing diets. Functional foods: Position of the American Dietetic Association. An Atkins diet often shows a greater reduction in triglycerides by comparison. As stated earlier, a low-fat, whole foods diet has been proven to reverse heart disease using actual measures of coronary atherosclerosis and myocardial perfusion, whereas none of the other three diets has been shown to do so. In addition, patients on an Atkins diet are counseled to take n-3 fatty acids in the form of fish oil (something else we agreed on), which is known to reduce triglycerides significantly. Although this study was limited by not having a randomized control group, the burden of proof is on the advocates of high-protein diets to show otherwise, especially given the large amount of data from other epidemiological studies, animal research, and randomized controlled trials linking the intake of a diet high in animal fat and protein with the incidence of CHD. A critique of the diet guru's views on high-protein diets, followed by a response from Ornish and a reply from the author. Am J Cardiol. Paradoxically, it may sometimes be easier for people to make more comprehensive changes in diet and lifestyle because they experience the benefits so quickly and to a much greater degree (25,64). Diet, obesity, and cardiovascular risk. There was a direct correlation between the intake of dietary cholesterol and fat and changes in coronary atherosclerosis. Buzzano notes that even high-fat dietsif they are high in the right fatscan be healthy and help you lose weight. Past studies also support the claim that low-carb diets are more effective than low-fat. The March 2014 study that Ornish cites as finding a 75 percent increase in premature deaths from all causes and a 400 percent increase in deaths from cancer and type 2 diabetes among heavy consumers of animal protein under the age of 65, also did not distinguish between types of animal protein. WebIn this study, premenopausal overweight and obese women assigned to follow the Atkins diet, which had the lowest carbohydrate intake, lost more weight and experienced more 1995;274:894-901. Accessed March 5, 2004. He should know better. Web3) Dr. Ornish focuses on the fact that eating eating vegetable diet can reduce weight loss. WebDean Ornish, in full Dean Michael Ornish, (born July 16, 1953, Dallas, Texas, U.S.), American physician and author whose approach to treating heart disease through radical Well, thats the pointwere not fat because were eating too little fat; were fat because were eating too much of everything. (All groups consumed about the same amount of protein.) Thus, by eating less fat, you reduce calories by reducing energy density without having to reduce volume. Anitschkow N. Experimental arteriosclerosis in animals. It is all about energy balance. Mean apo A-II levels did not change. Editor's Note: Our April 22 article elicited a lengthy response from Dean Ornish, which we publish here, along with a rebuttal from Melinda Wenner Moyer. 2003;26:302-307. A food or nutrient can be healthy without requiring that all other foods or nutrients be unhealthy. But his claims about the dangers of saturated fat and red meat go beyond the science and in some cases contradict it. Ive never said that protein is evil. In my oped, I clearly stated that its better to consume plant-based proteins than animal-based proteins, especially red meat. For instance, he wrote that animal proteins have been associated with higher disease and mortality risks in observational studies. which types of nerves carries stimuli away from the brain?, In planning his fitness goals, Alonso wants to make sure that he improves his fitness without pushing himself too hard too fast. The fractional catabolic rate (FCR) of apo A-I increased 11%, whereas its absolute transport rate decreased 14%. Taubes G. The soft science of dietary fat. The author, Dean Ornish, founder of the nonprofit Preventive Medicine Research Institute, is no newcomer to these nutrition debates. But they dont mask the truth; compared with individual studies, they get closer to it. Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study: a randomized trial, Journal of the American Medical Association. Whole foodssuch as whole grain products and fruits and veggiesare healthy, but I think that dairy products, fish and lean cuts of meat or poultry can also be part of a healthy diet, Steffen says. Only one person in the experimental group of the Lifestyle Heart Trial was smoking at baseline, so its unlikely that made a significant difference. He received an M.D. Below is my letter to the editor of The New England Journal of Medicine that they published about this study: Protein, too, doesnt look so evil when one considers the 2010 trial published in The New England Journal of Medicine that found individuals who had recently lost weight were more likely to keep it off if they ate more protein, along with the 2005 OmniHeart trial that reported individuals who substituted either protein or monounsaturated fat for some of their carbohydrates reduced their cardiovascular risk factors compared with individuals who did not. Dietary fiber, weight gain, and cardiovascular disease risk factors in young adults. Effect of whole grains on insulin sensitivity in overweight hyperinsulinemic adults. Im not cherry-picking data; Im looking at the preponderance of evidence from many studies by leading investigators such as those at Harvard School of Public Health. These associations were either abolished or attenuated if the proteins were plant derived.. In: Hennekens C, Manson J, eds. Dr. Atkins' Diet Revolution, first published in 1972 Dr. Robert C. Atkins, cardiologist Achieve a "metabolic advantage" with a four-phase diet low in carbohydrates The impact of protein intake on renal function decline in women with normal renal function or mild renal insufficiency. RESULTS: WebIn this video, we are comparing the new Atkins Protein Chips to the Quest Protein Chips. Fourth, the patients in our randomized controlled trial (JAMA. You can burn more calories by exercising. Dr. Atkins believed that cutting off carbohydrates and sugar will also do the same. A 2014 meta-analysis similarly reported much higher mortality risks associated with processed meat compared with red meat consumption and found no problems associated with white meat. HDL returns cholesterol to the liver for metabolism, a pathway known as reverse cholesterol transport. They should not be used to make claims about cause and effect; doing so is considered by nutrition scientists to be inappropriate and misleading. The reason: People who eat a lot of animal protein often make other lifestyle choices that increase their disease risk, and although researchers try to make statistical adjustments to control for these confounding variables, as theyre called, its a very imperfect science. The fact is, individuals on his diet are supposed to consume (pdf) no more than 10 percent of calories from fat, and thats very, very low compared to the average Americans adults intake of 33 percent of calories from fat. Over and over, Ive seen patients with coronary heart disease so severe that they cant walk across the street or work or play with their kids or make love or do much of anything without getting severe chest pain become pain-free after only a few weeks of making these diet and lifestyle changes. (1980) in internal medicine from Baylor College of Medicine in Houston. If his diet worksand again, we dont know for sure that it doesis that because it reduces protein or fat or refined carbohydrates? Harrisons Advances in Cardiology. To compare 4 weight-loss diets representing a spectrum of low to high carbohydrate intake for effects on weight loss and related metabolic variables. Get a Britannica Premium subscription and gain access to exclusive content. Compared to the reduced carbohydrate diet, the reduced fat diet led to a roughly 67 percent greater body fat loss. In people over 65 the authors observed that older people may benefit from more protein because they tend to be malnourished (living alone, poorer GI absorption, etcetera). J Am Diet Assoc. N Engl J Med. Am J Cardiol. You used to find a lot more people interested in The effect of high-protein diets on coronary blood flow. 1999;84:339-341A8. To understand better the mechanism of this phenomenon, Breslow and colleagues studied the turnover of HDL apolipoproteins (apo) A-I and A-II in 13 subjects on two contrasting metabolic diets. OBJECTIVE: The amount of dietary cholesterol and saturated fat in either a 30% fat diet or an Atkins diet may saturate and suppress the LDL receptor system, thereby leading to little fall in plasma LDL-C levels (29). Am J Kidney Dis. 1998;82:18T-21T. Am J Clin Nutr. As I wrote: I agree that replacing fat with sugar is not healthful, as Ive written about for decades. In other words, the diet I recommend causes weight loss, not weight gain. Arteriosclerosis. You can lose weight without feeling hungry or deprived. Whereas simple carbohydrates tend to have a high glycemic index/glycemic load and may be harmful for reasons discussed earlier, complex carbohydrates usually have a low glycemic index/glycemic load and are beneficial. For 37 years he has been touting the benefits of very low-fat, high-carbohydrate, vegetarian diets for preventing and reversing heart disease. J Clin Invest. This article was most recently revised and updated by, https://www.britannica.com/biography/Dean-Ornish, American Entertainment International Speakers Bureau - Biography of Dean Ornish, Ornish, Dean - Student Encyclopedia (Ages 11 and up). Nutrition is complex but there is little evidence our countrys worsening metabolic ills are the fault of protein or fat. For example, someone may indulge himself or herself one day and eat more healthfully the next. Zeman FJ, Hansen RJ. His dietary regimen was mostly an inverted version of the USDA pyramid that was high in fat and low in carbohydrates.
13 mai 2023