What the Fat?
For the past 30 years, the U.S. government has advised us to eat less fat. Yet despite the fact that Americans have reduced their intake of saturated fat during this time, the obesity rate has more than doubled, diabetes has tripled, and heart disease is still the country’s biggest killer.
New research, which included an analysis of nearly two dozen studies, suggests a reason why: the studies were wrong. As it turns out, they picked the wrong culprit, which led to the over-consumption of the real ones. Oops.
Many Americans have replaced the fat in their diets with high-glycemic carbohydrates (sugar, corn syrup, potatoes, rice, pasta, bread, etc.), trans fats and refined oils such as soybean and corn oil high in pro-inflammatory omega 6 fats. These increase the risk of obesity, diabetes and heart disease more than saturated fat.
The aforementioned study was published in the March 2014 edition of the Annals of Internal Medicine. It included data from several studies comparing the reported daily food intake of nearly 350,000 people against their risk of developing cardiovascular disease over a period of five to 23 years.
The analysis found no association between the amount of saturated fat consumed and the risk of heart disease.
These finding join the conclusions from other studies and authors (including Good Calories, Bad Calories by Gary Taubes), who for years have been arguing against the conventional wisdom that saturated fat increases cholesterol, and high cholesterol is what causes heart disease.
These assumptions were based on extrapolations, which were not supported by data. And who made these assumptions and extrapolations? Who recommended in 2004 that those at risk of heart disease reduce their LDL cholesterol to very low levels (below 100 mg/dL)? None other than a national panel made up of doctors who profited from the sale of cholesterol lowering medications.
One problem with the the old logic is that total cholesterol is not a great predictor of risk, and while saturated fat can elevate levels of “bad” (LDL) cholesterol, it also increases “good” (HDL) cholesterol.
A 2008 study published in the New England Journal of Medicine followed 322 moderately obese individuals for two years as they adopted one of three diets: a low-fat, calorie-restricted diet based on American Heart Association guidelines; a Mediterranean, restricted-calorie diet rich in vegetables and low in red meat; and a low-carbohydrate, non-restricted-calorie diet. Although the subjects on the low-carb diet ate the most saturated fat, they ended up with the healthiest ratio of HDL to LDL cholesterol and lost twice as much weight as their low-fat eating counterparts.
Another study in the Journal of the American Medical Association (1997) evaluated 65,000 women and found that the women who ate the most easily digestible and readily absorbed carbohydrates (highest glycemic carbs), were 47 percent more likely to acquire type 2 diabetes than those eating a diet with the lowest average glycemic index score. The amount of fat the women ate did not affect diabetes risk.
A 2007 Dutch study of 15,000 women published in the Journal of the American College of Cardiology found that women who were overweight and consumed meals with the highest average glycemic load were 79% more likely to develop coronary vascular disease than overweight women who consumed a low glycemic load diet.
The above findings may be explained in part by the yo-yo effects that high glycemic index carbohydrates have on blood glucose, which can stimulate fat production and inflammation, increase overall caloric intake and lower insulin sensitivity.
The government is in the process of revamping their nutritional recommendations. The question is: can the conventional “wisdom” that we have all been led to believe as gospel and that is so ingrained in our culture be challenged at this point? If so, what are the implications of what appears to have been a big, fat lie?
Oh, and did I mention that another issue facing regulatory agencies is that the sugared beverage industry is lobbying very hard in an attempt to cast doubt on all of these studies? Imagine that.
This weeks blog co-authored by Stephanie Lecovin, MS, RD www.nutritionhousecalls.com