Most recently, research on dietary fat and the prevention of metabolic diseases has focused on whole dietary patterns, such as the Mediterranean diet, and specific food sources of fatty acids. Thus, extensive evidence underpins current dietary recommendations and food-based guidelines to reduce SAFA intake and replace them with unsaturated fatty acids. However, several recent publications have questioned the evidence and rationale for dietary fat recommendations, especially for SAFA and omega-6 (n-6) PUFA (mainly linoleic acid, LA) intakes. These publications and the media attention they attracted have created confusion among consumers and health care professionals about the health effects of different dietary fats.
This narrative review provides an overview of recent analyses and selected studies on dietary fatty acids and the risk of CVD in humans.
There is also an extensive literature on the effects of dietary fats on other CVD risk factors and endpoints. The researchers describe human studies with research designs of the highest relevance for evaluating the effects of diet on human health and setting guidelines. These include long-term randomized controlled trials on clinical endpoints (RCTs), prospective analyses from large population studies, and controlled dietary intervention studies on established markers of cardiometabolic risk (metabolic trials).
This review therefore also considers new insights in the effects of dietary fatty acids on markers of insulin sensitivity and risk of type II diabetes mellitus (T2DM).
Improving fatty acid intakes is an important element of diet and lifestyle approaches that can effectively lower the risk of CVD. Recommendations for intakes of fatty acids and other nutrients are increasingly being translated into practical food-based dietary guidelines for the population.
These unanimously advise limiting the consumption of SAFA-rich fats and foods, avoiding TFA, and consuming more foods rich in unsaturated fatty acids. In practice, this implies the consumption of low-fat dairy products, lean meats, more vegetable oils, and vegetable oil-based foods, nuts, seeds, and the regular consumption of fatty fish. A healthy eating pattern also includes a greater intake of vegetables and fruits, carbohydrates from whole grains, a variety of protein foods (seafood, lean meat and poultry, eggs, legumes, and nuts), and low intakes of added sugar and sodium.