From the Guidelines
Dietary mono- and poly-unsaturated fats should make up the majority of your fat intake, replacing saturated and trans fats whenever possible, as they have been shown to decrease the risk of coronary artery disease (CAD) and improve overall health outcomes. According to the most recent and highest quality study 1, increasing consumption of mono- or polyunsaturated fats decreases the risk of CAD. The study suggests that efforts to reduce fat consumption over the past 40 years led to increased intake of refined carbohydrates, which increased triglyceride levels and the risk of type 2 diabetes, and contributed to weight gain, increased LDL cholesterol levels, and decreased high-density lipoprotein cholesterol levels. Some key points to consider when implementing this recommendation include:
- Consuming at least two servings of fatty fish weekly for omega-3 polyunsaturated fats, as they provide additional benefits for brain health and reducing inflammation 1
- Using olive oil as your primary cooking oil, as it is a rich source of monounsaturated fats, which seem to be beneficial for preventing cardiovascular disease (CVD) 1
- Incorporating a small handful of nuts or seeds daily, as eating nuts has been associated with health benefits such as decreased risk of diabetes, CVD, and mortality, and lower body weight 1
- Limiting the use of corn and vegetable oils, which can lead to an unbalanced ratio of omega-3 to omega-6 fatty acids, resulting in increased activation of the arachidonic acid pathway and increased rates of thrombosis, vasospasm, cancer, obesity, and allergic and inflammatory disorders 1 Another study 1 also supports the recommendation to replace saturated fatty acids with polyunsaturated fatty acids, as it reduces the risk of CAD by 2-3% when 1% of energy intake from saturated fatty acids is replaced by polyunsaturated fatty acids. Overall, the evidence suggests that dietary mono- and poly-unsaturated fats play a crucial role in maintaining good health and reducing the risk of chronic diseases, and should be prioritized in one's diet.
From the Research
Dietary Mono- and Poly-unsaturated Fats
- Dietary mono- and poly-unsaturated fats are associated with a decreased risk of coronary heart disease, as stated in 2.
- Omega-3 fatty acids, a type of polyunsaturated fatty acid, have been studied for their potential therapy in various medical conditions due to their anti-inflammatory properties 2.
- Monounsaturated fatty acids are often regarded as healthy, but recent findings have questioned their impact on coronary heart disease, indicating that more conclusive studies are needed 3.
- Both monounsaturated and polyunsaturated fatty acids appear to reduce total and LDL-cholesterol compared to saturated fatty acids, although their effect on HDL is less clear 3.
Comparison of Mono- and Poly-unsaturated Fats
- Polyunsaturated fatty acids may protect against atherosclerosis, and recommendations to substitute monounsaturated fatty acids for polyunsaturated fatty acids seem premature without further research 3.
- Epidemiologic research has shown that replacing saturated fatty acids with unsaturated fat, including polyunsaturated and monounsaturated fatty acids, is associated with a reduction in coronary heart disease events and death 4.
- Controlled clinical studies have demonstrated that saturated fatty acids increase LDL cholesterol, while polyunsaturated fatty acids have the greatest LDL-cholesterol-lowering effect when replacing saturated fatty acids 4.
Health Outcomes and Dietary Fat Intake
- A systematic review of the effect of dietary saturated and polyunsaturated fat on heart disease found that replacing saturated fat with polyunsaturated fat lowers the risk of CVD mortality and CHD events 5.
- A scoping review of systematic reviews on dietary fat intake and health outcomes found that replacing saturated fatty acids with polyunsaturated and/or monounsaturated fatty acids improves blood lipids and glycemic control, with the effect of polyunsaturated fatty acids being more pronounced 6.
- The available evidence suggests that it is reasonable to recommend replacing saturated fatty acids with monounsaturated and polyunsaturated fatty acids and avoiding the consumption of industrial trans-fatty acids 6.