“It was twenty years ago today
Sgt. Pepper taught the band to play….”
~The Beatles, Sgt. Pepper’s Lonely Hearts Club Band (1967)
It is actually now more than a half century since Sgt. Pepper taught the band to play, and that iconic work has withstood the test of time. But other similarly aged concepts continue to crumble under the weight of exposure, like a sugar cookie left out too long on the counter.
Over 50 years ago, luminaries like Professor John Yudkin argued that refined carbohydrates were behind the rise of cardiovascular disease observed in post-World War II America. Contrary opinions like those of Ancel Keys prevailed; and the course was set for the next several decades. It has been an El Dorado-ian like expedition, searching for health among ruins of low-fat approaches.
“Throughout the 1980s and 1990s, the USDA treated fat as the primary harm in the American diet,” according to Marion Nestle, PhD; former chair of the Department of Nutrition, Food Studies, and Public Health at New York University. It was an undertaking many researchers feel was never grounded in science. At the time the guidelines were issued in 1977, no randomized controlled trial (RCT) had tested the proposed dietary fat sanctions; limits of 30% total fat and 10% saturated fat. The dietary fat restrictions were based on six dietary trials, five of them secondary prevention, consisting of a grand total of 2467 males. The implementation immediately impacted 220 million Americans and 56 million in the UK, all based on at best specious reasoning from less than 2500, mostly middle-aged, Caucasian, mostly unhealthy, men.
The guidelines encouraged Americans to eat hefty amounts, 55-60% of daily energy, of carbohydrates like refined white bread and sugar-laden cereals. Advice, which according to experts like Dr. Robert Lustig; Professor of Pediatrics, Division of Endocrinology, University of California, San Francisco “is exactly backwards if you want to improve health and lower body weight.”
Nonetheless, Americans-contrary to popular opinion-proved to be good listeners. During the ensuing decades, total fat decreased from 36.9% to 32.8% for men and 36.1% to 32.8% for women; all statistically significant. Even more impressively, saturated fat decreased from13.5% to 10.9% for men and from 13.0% to 11.0% for women; again statistically significant reductions.
How did that work out for us?
Over the same time course, obesity increased from 14.5% to 30.9%. As we focused on fat; the rise in diabetes and other inflammatory disabilities and diseases continued to increase. Diabetes reached epidemic proportions, affecting over 20% of the population by 2011. The role of fats was confined to focusing on a test tube and their impact on cholesterol value. Little effort was made to elucidate or understand their physiological role and importance; or even their now recognized pleiotropic effect on other lipid parameters beyond LDL cholesterol.
Despite well done meta-analysis, observational studies, and RCTs suggesting antithetical results, there continues to be a doubling down on the low fat, low saturated fat approach. When the data revealed less than a decade ago “that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD,” or even more recently, that the “current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats,” the response by organizations promoting the low-fat approach has been an argument from inappropriate authority; argumentum ad verecundium. The result is that the findings are rejected, ignored, or labeled a “paradox”.
Earlier this year, in a position paper fraught with conflict and contradiction, the American College of Cardiology (ACC) again blindly pushed the anti-fat agenda. , A whole-hog adoption from the American Heart Association (AHA) shortly followed. The AHA even went so far as to single out coconut oil (a vegetable oil, but high in saturated fat), not because of any evidence of significant clinical endpoints (like it causes heart attacks or eating it increases early mortality), but simply because it raises LDL cholesterol (it also raises HDL). Like many other oils, these fats and others also affect total cholesterol, HDL cholesterol, triglycerides, apolipoprotein B, apolipoprotein A1 and assorted ratios of these compounds to name but a few. Therefore, it is imperative that recommendations be based on observable and observed outcomes.
Such was the approach of a recent seminal study, the PURE (Prospective Urban Rural Epidemiology) study. Published in a series of 3 articles in The Lancet, the researchers discussed their findings from over 135,000 people in 18 countries spanning 5 continents. There were several (statistically significant) take-away points:
• You do need to eat more fruits and vegetables. Increasing fruit and vegetable consumption reduces non-cardiac and total early mortality-to a point. While current recommendations call for at least 5 servings per day, the study seemed to suggest that the health benefits plateau after 3-4 servings per day. Such findings make achieving goals more palatable in terms of both logistics and economics; as fresh fruits and vegetables can account for a large percentage of the grocery bill.
• You can enjoy carnivory. Total and animal protein was associated with a lower risk of non-cardiac and total early mortality. Eating more protein, 19.7% compared to 10.8%, reduced non-cardiac mortality by 15% and total early mortality risk by 12%. Eating more meat and fish, increasing the intake of animal protein, was associated with lower total early mortality. No such association was found with plant protein.
• You can eat meat. The more fat you ate, the longer you lived. In complete drop the serving platter moment, those who consumed the most fat compared to those who consumed the least, 35.3% compared to 10.6%, had a 23% reduction in total early mortality. Yes, you read that correctly; the more fat you ate, the longer you lived and you did not do so at the risk of increased cardiovascular disease. In fact, there was a reduction in non-cardiovascular mortality and no association with an increased risk of major cardiovascular disease, myocardial infarction (heart attack), or cardiovascular disease mortality.
• You can eat red meat. The news could not get any more scrumptious. Long taboo because of its fat and particularly saturated fat content; red meat is finally being recognized within the pantheon of important and delectable foods. As previous studies and analysis have suggested, the PURE study prospectively confirmed no association between the consumption of saturated fat and heart disease or risk of early death. In fact, higher saturated fat intake, 13.2% versus 2.8%, was associated with a lower total early mortality; a 14% decreased risk of an early demise enjoying red meat, butter, cheese and other full sat fat pleasures. In an irony that could only be envisioned as a complete bitch-slap to the ACC and the AHA in light of their recent admonition disparaging coconut oil; eating more saturated fat reduced the risk of stroke by 21%, as well as non-cardiovascular mortality by 14%.
• You can pile those burger patties on a (single) bun. In a threshold inverse of that seen with fruits and vegetables, consumption of carbohydrates seems benign-to a point. There did not seem to be a detrimental effect until carbs accounted for approximately 60% of daily total energy. In an interesting aside, the governmental guidelines within the infamous food pyramid called for 55-60% of daily energy to come from carbs like breads, cereal, rice, etc. At the highest levels of consumption, exceeding this threshold translated into a 28% increased risk of total early mortality. In light of the benefit seen with more fruit and veg; it is fair to extrapolate this as a warning against excessive, likely refined, carbohydrate consumption.
• Fat is PHAT; protective, healthy and tasty. Total fat and saturated fat was associated with health benefits. At increased levels of consumption, total fat, saturated fat, and unsaturated fat were not associated with an increased risk of heart attack or mortality from cardiovascular disease.
These results are shocking, given that mere weeks ago, the American Heart Association issued a new “advisory” recommending once again the need to minimize intake of saturated fat and replacing it with polyunsaturated fat or carbohydrate. In fact, this study suggests as other trials have, that a “very low saturated-fat intake appears harmful. Current guidelines that recommend total fat below 30% and saturated fat below 10% of energy intake are not supported by our data,” said PURE co–lead author Dr Mahshid Dehghan.
Lead researcher Dr. Yusuf commented further: “The AHA guidelines are not based on the best evidence—saturated fat was labeled as a villain years ago, and the traditional church has kept on preaching that message. They have been resistant to change.”
Such welcome change for the heretics amongst us is, PURE-ly delicious.
References:
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