Cardiovascular disease is the leading cause of death world-wide. Efforts to prevent cardiovascular disease can have a major impact on global cardiovascular disease mortality. This Presidential Advisory from the American Heart Association reviewed the scientific evidence of multiple studies regarding the impact of dietary saturated fat on cardiovascular disease. It strongly concludes that reducing dietary intake of saturated fat and replacing it with unsaturated fat, especially polyunsaturated fat, will reduce the rate of cardiovascular disease. The following are key points to remember:

1. Multiple randomized clinical trials, meta-analyses, prospective observational studies, and animal studies all support the concept of replacement of dietary saturated fats with unsaturated fats to reduce cardiovascular disease. Reducing dietary saturated fat and replacing it with polyunsaturated vegetable oil reduced cardiovascular disease by around 30%, similar to results from statin therapy. Prospective observational studies showed that reducing saturated fat and replacing it with polyunsaturated or monounsaturated fat caused 25% and 15% reductions in coronary heart disease (CHD), respectively. Mortality overall and from other causes was also reduced.
2. Replacing dietary saturated fats with carbohydrates, especially refined carbohydrates, does not reduce cardiovascular disease. Substitution with refined carbohydrates caused a 1% increase in CHD; substitution with whole grain carbohydrates caused a 9% reduction.
3. Both polyunsaturated fats and monounsaturated fats are effective in reducing cardiovascular disease. The effect is greatest for polyunsaturated fats.
4. Studies in which saturated fats were replaced by carbohydrates resulting in a low-fat diet did not reduce cardiovascular disease.
5. Animal studies have shown that a diet high in saturated fats raises low-density lipoprotein (LDL) cholesterol and increases coronary atherosclerosis, and a diet low in saturated fat but high in polyunsaturated fat has the reverse effect.
6. Replacement of saturated fat with polyunsaturated fat, monounsaturated fat, or carbohydrates results in a reduction in LDL cholesterol; the reduction is greatest for polyunsaturated fats and least for carbohydrates.
7. Coconut oil increases LDL without known beneficial effects. Dairy fat increases LDL; substitution by polyunsaturated fats causes a 24-25% lower risk of cardiovascular disease and stroke. Trans-unsaturated fats increase cardiovascular disease. Omega-3 vegetable oil is associated with a lower risk of fatal but not overall CHD, possibly due to antiarrhythmic properties.
8. Randomized clinical trials of a Mediterranean diet in conjunction with substitution of polyunsaturated or monounsaturated fats for saturated fats resulted in significantly reduced cardiovascular disease in the intervention arms but not in control groups assigned to a low-fat diet.

The American Heart Association Presidential Advisory strongly concludes that reducing dietary intake of saturated fat and replacing it with unsaturated fat, especially polyunsaturated fat, will reduce cardiovascular disease incidence. Reduction in total fat (i.e., a low-fat diet) is not recommended. This dietary shift should occur concurrently with the adoption of an overall healthy diet such as the Dietary Approaches to Stop Hypertension diet or Mediterranean diet.

Keywords: Carbohydrates, Cholesterol, LDL, Coronary Artery Disease, Diet, Fat-Restricted, Diet, Mediterranean, Dietary Carbohydrates, Dietary Fats, Dietary Fats, Unsaturated, Fats, Unsaturated, Plant Oils, Trans Fatty Acids

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