Epidemiologic Data Linking Diet to Hyperlipidemia and Arteriosclerosis

There is little debate that an elevated plasma cholesterol level, specifically an elevated plasma LDL cholesterol level, increases cardiovascular disease risk. Data from inter- and intrapopulation studies have clearly demonstrated that as total and LDL cholesterol levels increase, cardiovascular disease risk increases. Although this relationship is generally accepted, the specifies of the relationship generate debate. Relevant questions pertain to the actual level of plasma cholesterol at which cardiovascular disease risk is increased, whether the relationship holds true across all age groups and both sexes, and what contributions plasma HDL levels and the plasma LDL/HDL ratio make to cardiovascular disease risk independent of plasma LDL levels. Irrespective of these uncertainties, the evidence that elevated plasma LDL cholesterol levels constitute an independent risk factor for cardiovascular disease has been a major component in studying the genetic and environmental factors involved in hypercholesterolemia. Epidemiologic data reveal relationships between a number of dietary elements and elevated plasma cholesterol levels with the strongest relationships between dietary fatty acids, plasma cholesterol levels, and cardiovascular disease incidence. The data from a variety of epidemiologic investigations, both cross-cultural and cross-sectional, indicate that plasma total cholesterol levels are increased by saturated fat intake and obesity. HDL cholesterol levels are decreased by intakes of low-fat, high-carbohydrate diets, a high BMI, and lack of activity and increased by intake of dietary fat, alcohol, and physical activity. Controlled clinical trials have provided verification of these epidemiologic observations in practically every case.(ABSTRACT TRUNCATED AT 250 WORDS)