Information about Healthy Fats and Dementia Risk

Omega-3 fatty acids, a healthy type of fat found primarily in fatty fish, reduce the risk of coronary heart disease and appear to lower the risk of dementia, including Alzheimer's disease. Omega-3 fatty acids have anti-inflammatory effects, and inflammation is believed to play a role in the development of Alzheimer's disease.

In a study published in the Archives of Neurology, researchers assessed omega-3 intake among nearly 900 older people (average age 76) who did not have dementia. After nine years, the risk of developing dementia was slashed nearly in half among those who consumed the most omega-3 fatty acids (equivalent to three servings of fish per week).

Fatty fish (such as mackerel, salmon, and sardines) are the richest source of omega-3 fatty acids. But these beneficial fats are also found in smaller amounts in canola oil and in flaxseeds, walnuts, and soybeans as well as the oils of these plants. Omega-3 fatty acid supplements also are available.

The American Heart Association recommends at least two servings of fatty fish per week in addition to oils, nuts, and seeds high in omega-3 fatty acids to protect against heart disease. The results of recent studies support these recommendations for brain health, too.

The overall dietary pattern known as the Mediterranean diet, which is rich in omega-3 fatty acids from fish, has been found to reduce Alzheimer's risk by 40 to 60 percent. The diet includes lots of fruits, vegetables, beans, whole grains, and nuts and is rich in healthy, monounsaturated fats (found in olive and canola oils, almonds, and avocados). Dairy products, eggs, and poultry are eaten only in moderation, and red meat consumption is rare.

A 2009 study in the Journal of the American Medical Association showed that higher Mediterranean-type diet adherence (as well as higher physical activity) were independently associated with reduced risk for Alzheimer's. Results of another study published in The New England Journal of Medicine in February 2013, showed that the Mediterranean diet also reduces heart disease risk.

Information about Unhealthy Fats and Dementia Risk

A high intake of saturated fats and trans fats appears to increase the risk of dementia. In an Archives of Neurology report, people with a high intake of saturated fats (found in animal products) and trans fats (found abundantly in margarines, commercial bakery products, and snack foods) were twice as likely to develop Alzheimer's disease after four years as people who rarely consumed these unhealthy fats.

The Institute of Medicine recommends restricting consumption of trans fats to a minimum. The Nutrition Facts panel on packaged foods now lists the amount of trans fat a product contains. In a product's ingredients list, trans fats are listed as "hydrogenated" or "partially hydrogenated" oils. Some food manufacturers are reformulating their products to reduce or eliminate trans fats.

Publication Review By: Peter V. Rabins, M.D., M.P.H.; the Editorial Staff at

Published: 08 Mar 2011

Last Modified: 01 Dec 2014