In order to clear up confusion about how different dietary fats relate to heart health, the American Heart Association published a Presidential Advisory on Dietary Fats and Cardiovascular Disease. In this paper, the researchers reviewed randomized controlled trials (the gold standard of nutrition research) as well as prospective observational studies (following large groups of people over long periods of time and noting their health outcomes). After reviewing all of the evidence, they concluded that replacing saturated fat (the types of fats found in red meat, butter, and milk) with polyunsaturated fat (found in fish, nuts, and seeds) can lower the risk of heart disease by 30%, which is on par with what cholesterol lowering medications can achieve. Similarly, they found that eating more monounsaturated fat (found in avocados, olive oil, and canola oil), more polyunsaturated fat, and less saturated fat is linked with lower rates of heart disease. Saturated fat is also linked with higher rates of “bad cholesterol” (LDL), which is thought to build up in artery walls and pose a risk for heart disease. These findings are in line with healthy dietary patterns around the world, including the Mediterranean diet.
Circulation. 2017 Jun 15. [Epub ahead of print.] (Sacks FM et al.)