How does fat intake affect health?

From the Guidelines

Fat intake affects health in complex ways, and the most recent evidence suggests that moderate consumption of all types of fat, including saturated, monounsaturated, and polyunsaturated fats, may be associated with lower risk of death and neutral association with cardiovascular disease (CVD) 1. The relationship between dietary fats and health outcomes has been extensively studied, and the evidence suggests that the type and amount of fat consumed are crucial in determining the risk of chronic diseases such as heart disease and diabetes.

• Unsaturated fats, including polyunsaturated and monounsaturated fats, have been shown to improve cholesterol levels and reduce inflammation, while excessive saturated fat may increase LDL cholesterol and heart disease risk 1.
• The PURE study, a large and diverse study of 135,000 people from 18 countries, found that increased consumption of all types of fat was associated with lower risk of death and had a neutral association with CVD 1.
• A diet high in carbohydrate was associated with higher risk of death but not with risk of CVD, suggesting that the type of macronutrient is more important than the amount of fat consumed.
• The evidence also suggests that the ratio of omega-3 to omega-6 fatty acids is important, and that an unbalanced ratio favoring omega-6 can lead to increased activation of the arachidonic acid pathway, resulting in increased rates of thrombosis, vasospasm, cancer, obesity, and allergic and inflammatory disorders 1.
• In terms of specific recommendations, the American Heart Association recommends a population-wide goal of 7% of energy from saturated fat, and a goal of 1% trans fatty acids, while emphasizing the importance of replacing saturated and trans fats with unsaturated fats, such as polyunsaturated and monounsaturated fats 1. Key points to consider when making dietary recommendations include:
• Emphasizing whole, unprocessed foods such as fruits, vegetables, whole grains, lean proteins, and healthy fats, rather than relying on processed and packaged foods.
• Encouraging a balanced diet that includes a variety of foods from all food groups, rather than focusing on a single nutrient or food group.
• Recognizing that individual nutritional needs may vary, and that dietary recommendations should be tailored to meet the unique needs and health goals of each person.

From the Research

Effects of Fat Intake on Health

• Fat intake has been shown to have both positive and negative effects on health, depending on the type of fat and the overall dietary pattern 2, 3, 4, 5, 6
• A diet high in saturated fatty acids (SFA) is associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD) 4
• Replacing SFA with unsaturated fatty acids, particularly polyunsaturated fatty acids, may reduce ASCVD risk 4
• The Mediterranean diet, which is rich in monounsaturated fatty acids from olive oil and other sources, has been shown to have beneficial effects on cardiovascular risk factors and reduce the risk of cardiovascular disease 2, 3, 5, 6

Cardiovascular Risk Factors

• The Mediterranean diet has been shown to lower blood pressure, improve lipid profiles, and reduce inflammation, all of which can help to reduce the risk of cardiovascular disease 2, 3, 5
• A diet high in SFA has been shown to raise low-density lipoprotein cholesterol (LDL-C) levels, which can increase the risk of ASCVD 4
• Replacing SFA with unsaturated fatty acids can help to lower LDL-C levels and reduce the risk of ASCVD 4

Dietary Recommendations

• The current recommendation is to limit SFA intake to <10% of total daily energy for the general healthy population and further (e.g., to 5-6% of total daily energy) for patients with hypercholesterolemia 4
• Adhering to a Mediterranean diet is strongly recommended because of its ability to lower cardiovascular disease and total mortality risk 2, 3, 5, 6
• Individuals should continue to minimize saturated fats and refined carbohydrates, eliminate trans-fat, and increase fruits, vegetables, whole grains, low-fat dairy, and fish or other omega-3 fatty acids 6