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Dietary Guidelines Panel Needs To Get It Right On Saturated Fat
The federal government has a wonderful opportunity, as it prepares the next edition of the Dietary Guidelines for Americans, to get it right and reverse decades of wrong-headed advice on saturated fat consumption. We shall see if the government takes advantage of this opportunity.
Since the first edition of the Dietary Guidelines was issued in 1980, the advice on saturated fat has been pretty much the same: limit your intake. But lately it’s been looking more and more like this is faulty advice at best and potentially hazardous advice at worst.
And it’s also looking like the basis for the “reduce intake of saturated fats” advice was incorrect in the first place.
The federal government (specifically, the US Departments of Agriculture and Health and Human Services) updates its Dietary Guidelines for Americans every five years, and the next edition of scheduled for release in the fall of 2015.
Beginning with the 1985 edition, HHS and USDA have appointed a Dietary Guidelines Advisory Committee, comprised of nationally recognized experts in the field of nutrition and health, to review the scientific and medical knowledge current at the time. Based on its review of the literature, the DGAC prepares a report for the HHS and USDA secretaries that provides recommendations for the next edition of the Dietary Guidelines.
The most recent DGAC report, released in 2010, had this to say about saturated fat intake: “Strong evidence indicates that intake of dietary SFA (saturated fatty acids) is positively associated with intermediate markers and end point health outcomes for two distinct metabolic pathways: 1) increased serum total and LDL cholesterol and increased risk of CVD (cardiovascular disease) and 2) increased markers of insulin resistance and increased risk of T2D (type 2 diabetes). Conversely, decreased SFA intake improves measures of both CVD and T2D risk.”
And so the most recent edition of the Dietary Guidelines for Americans, released in January of 2011, offered this advice: “Consuming less than 10 percent of calories from saturated fatty acids and replacing them with monounsaturated and/or polyunsaturated fatty acids is associated with low blood cholesterol levels, and therefore a lower risk of cardiovascular disease.”
But since that publication was released, evidence has been mounting against this longstanding advice on saturated fatty acid intake and health.
For example, last October, Aseem Malhotra, a cardiology specialist at Croydon University Hospital in London, argued on bmj.com that the scientific evidence shows that the advice to reduce saturated fat intake has, “paradoxically, increased our cardiovascular risks.”
Recent prospective cohort studies “have not supported any significant association between saturated fat intake and cardiovascular risk” Malhotra noted. “Instead, saturated fat has been found to be protective.” And one study found that higher concentrations of plasma trans-palmitoleic acid, a fatty acid found mainly in dairy products, was associated with a lower incidence of diabetes in adults (for more details, please see “Reducing Saturated Fat Intake Has Increased, Not Cut, Cardiovascular Risk: Cardiologist,” on page 7 of our Oct. 25, 2013 issue).
More recently, in an editorial in the open access journal Open Heart, Dr. James J. DiNicolantonio, a leading US cardiovascular research scientist and doctor of pharmacy, went even further, and even further back in time.
DiNicolantonio noted that past data promoted by researcher Ancel Keys starting in the 1950s showing that an increased percentage of fat calories consumed increases the risk of death “are not valid (and certainly could never have proved causation). These data seemingly lead us down the wrong ‘dietary-road’ for decades to follow...”
DiNicolantonio concluded that the benefits of a lowfat diet, particularly a diet replacing saturated fats with carbohydrates or omega-6 polyunsaturated fatty acids, are “severely challenged,” and that dietary guidelines “should assess the totality of the evidence and strongly reconsider their recommendations for replacing saturated fats with carbohydrates” or omega-6 polyunsaturated fats.
And even more recently, an international research collaboration led by the University of Cambridge concluded that current evidence “does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats.” (For more details on these two studies/commentaries, please see “Diets Low In Saturated Fats Don’t Curb Heart Disease; Dietary Advice Should Be Reviewed,” on page 6 of last week’s paper.)
Doubts about the supposed hazards of saturated fats actually date back more than a decade. Back in 2001, Gary Taubes, writing in Science magazine, noted that “the science of dietary fat is not nearly as simple as it once appeared” and that “the data remain ambiguous as to whether low-fat diets will benefit healthy Americans.”
All in all, there’s plenty of information for the Dietary Guidelines Advisory Committee to digest when it comes to “new thinking” on the health impacts of saturated fat intake. And much of that “new thinking” contradicts, or at least seriously questions, the long-held belief that saturated fat intake is harmful to health.
We’re not optimistic that this DGAC will get it right when it comes to saturated fat advice. But recent research at least indicates that the number of skeptics continues to increase. DG
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