Key Findings:
Dietary recommendations have for decades identified that a reduction in fat intake is necessary to lower risk of coronary heart disease (CHD). Research has moved to the findings that it is the type of fat, but not total amount of fat, which impacts blood cholesterol levels. Replacing saturated fat with unsaturated fat has been found in epidemiologic studies and controlled clinical trials to more effective in lowering risk of CHD than easting less fat overall. Increased consumption of n-3 fatty acids from fish or plant sources lowers risk of CHD as reported in numerous prospective cohort studies and secondary prevention trials. More recent national dietary guidelines now focus on different types of fat. Further the authors argue against recommendations for a low-fat diet for weight loss as long-term clinical trials have not supported a relationship between low fat and weight reduction. Further research is required to determine the optimal mixture of different fatty acids in lowering the risk of CHD.
Abstract:
In the past several decades, reduction in fat intake has been the main focus of national dietary recommendations to lower risk of coronary heart disease (CHD). Metabolic studies have long established that the type of fat, but not total amount of fat, predicts serum cholesterol levels. Results from epidemiologic studies and controlled clinical trials have indicated that replacing saturated fat with unsaturated fat is more effective in lowering risk of CHD than simply reducing total fat consumption. Prospective cohort studies and secondary prevention trials have provided strong evidence that a higher intake of n-3 fatty acids from fish or plant sources lowers risk of CHD. Recent national dietary guidelines have shifted the emphasis from total fat reduction to distinguishing different types of fat. During the past several decades, reduction in fat intake has been the main focus of national dietary recommendations to decrease risk of coronary heart disease (CHD). Several lines of evidence, however, have indicated that types of fat have a more important role in determining risk of CHD than total amount of fat in the diet. Metabolic studies have long established that the type of fat, but not total amount of fat, predicts serum cholesterol levels. In addition, results from epidemiologic studies and controlled clinical trials have indicated that replacing saturated fat with unsaturated fat is more effective in lowering risk of CHD than simply reducing total fat consumption. Moreover, prospective cohort studies and secondary prevention trials have provided strong evidence that an increasing intake of n-3 fatty acids from fish or plant sources substantially lowers risk of cardiovascular mortality. In this article, we review evidence from epidemiologic studies and dietary intervention trials addressing the relationship between dietary fat intake and risk of CHD, with a particular emphasis on different major types of fat, n-3 fatty acids and the optimal balance between n-3 and n-6 fatty acids. We also discuss the implications of the available evidence in the context of current dietary recommendations. (Author’s abstract)
Link to Full Text