Saturated fat, carbohydrate, and cardiovascular disease

Area of Science:

• Nutrition Science
• Cardiovascular Health
• Dietary Epidemiology

Background:

• Dietary recommendations often focus on reducing saturated fat for cardiovascular disease (CVD) prevention, primarily to lower LDL-cholesterol.
• The impact of saturated fat reduction depends on the macronutrient replacing it.

Purpose of the Study:

• To evaluate the evidence for saturated fat reduction in CVD prevention, considering macronutrient replacement.
• To assess the effects of replacing saturated fat with polyunsaturated fat, monounsaturated fat, or carbohydrates on CVD risk and lipid profiles.

Main Methods:

• Review of clinical trials and prospective epidemiologic studies examining dietary fat intake and CVD events.
• Analysis of studies that replaced saturated fat with other macronutrients, focusing on changes in LDL-cholesterol, HDL-cholesterol, and triglycerides.

Main Results:

• Replacing saturated fat with polyunsaturated fat generally reduced CVD events, though some studies showed no effect.
• Replacing saturated fat with carbohydrates, especially refined carbohydrates, can worsen atherogenic dyslipidemia, increasing triglycerides and small LDL particles while decreasing HDL-cholesterol.
• An independent association between saturated fat intake and CVD risk is not consistently shown, but some evidence suggests increased risk in younger individuals and women.

Conclusions:

• Substitution of dietary polyunsaturated fat for saturated fat may lower CVD risk.
• Replacing saturated fat with carbohydrates, particularly refined types, offers little cardiovascular benefit and can exacerbate dyslipidemia.
• Dietary strategies for managing CVD risk associated with dyslipidemia should prioritize limiting refined carbohydrate intake and reducing adiposity.