By Tamara Brown, M.H.P., L.D., R.D.

Tamara Brown, MPH, LD, RD

For years we have been told to steer clear of saturated fats because they raise LDL, or "bad" cholesterol levels, and therefore increase risk for heart disease. However, research is proving this message to be untrue. 

How saturated fat got such a bad reputation
Based on a "poor science" study from the 1950's, Ansel Keys hypothesized that dietary fat and cholesterol levels were linked to levels of fat and cholesterol in the blood. This diet-heart hypothesis appeared to be true because he used data from only seven countries where higher saturated fat intake and higher levels of heart disease occurred (data for all countries did not support a correlation between higher saturated fat intake and higher levels of heart disease). Without any further studies or evidence, the American Heart Association began recommending a diet low in saturated fats and high in carbohydrates and vegetable oils for heart health. Word spread about the study and new diet recommendations and since the '60s, Americans have been consuming this diet, void of good fats and high in sugary, processed foods. If Keys' research were true, this change in diet should have had a positive effect on our cholesterol levels. Instead over twenty million Americans are on statin drugs to lower cholesterol! Something must be wrong with his theory.  

The true causes of unhealthy cholesterol levels
There is not sound science behind the prevention message that reducing saturated fat in the diet lowers our risk of unhealthy cholesterol and heart disease. A recent meta-analysis of twenty-one studies, published in the American Journal of Clinical Nutrition, found that "there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of coronary heart disease or cardiovascular disease."¹ Ironically, the foods that raise our cholesterol levels are the very foods we have been advised to consume--processed carbohydrates, margarine and vegetable oils. In an article entitled, "Are Refined Carbohydrates worse than Saturated Fats," Dr. Frank Hu from the Harvard Medical School said, "In this era of widespread obesity and insulin resistance, the time has come to shift the focus of the diet-heart paradigm away from restricted fat intake and toward reduced consumption of refined carbohydrates." ²

Gary Taubes examined decades of research on heart disease in his book Good Calories, Bad Calories. He concluded that cholesterol is not the cause of heart disease, but that triglycerides cause the problem. Your triglyceride level is affected by carbohydrates, not saturated fats. Foods like pasta, bread, crackers, and cookies, are what cause your triglycerides to rise. When you replace processed carbohydrates with real carbohydrates, such as vegetables; and replace man-made fats with real fats such as butter, nuts, olive oil, or avocados, your cholesterol levels normalize.  

At Nutritional Weight & Wellness, we have been teaching people how to lower cholesterol for years by reducing sugars and processed carbohydrates and by avoiding trans-fats such as margarine and other refined oils. Saturated fat isn't the problem after all. Extensive research has found that processed carbohydrates and foods high in trans-fasts and man-made oils increase our risk for cardiovascular disease.  

For more information on cholesterol, tune into Dishing Up Nutrition this Saturday (11/5) at 8am on FM107 when we tackle the topic of cholesterol.

1 Siri-Tarino, PW, Sun Q, Hu FB, Krauss RM. Meta-Analysis of Prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin Nutr January 2010 ajcn.27725

2 Hu, FB. Are refined carbohydrates worse than saturated fats? Am J Clin Nutr June 2010 vol. 91 no. 6 1541-1542