Get the Facts about Healthy Fats: Omega-3 and Omega-6 Fatty Acids

Rachel Griehs, RD, LDN, member of the Penn Metabolic and Bariatric Surgery team, explains the nutritional importance of essential fatty acids.


For years experts have been saying that all fats are bad, but it turns out that is not the case. Among the healthy fats are omega-3 and omega-6, which are considered essential fatty acids. Although the body needs them, it cannot produce them itself, which is why they must be incorporated into your diet.

There are three types of omega-3 fatty acids:
1.    Alpha-linoleic (ALA)
2.    Docosahexaenoic (DHA)
3.    Eicosapentaenoic (EPA)

ALA is found in plant foods and flaxseed is the richest source. EPA and DHA are found in similar foods, including seafood, algae and higher fat cold water fish, such as mackerel, albacore tuna, salmon, sardines, Atlantic herring, swordfish and lake trout. Enriched eggs are also a good source of omega-3 fatty acids because the egg-producing hens are fed a diet that includes flaxseed and algae. As a result, these eggs contain all three types of omega-3 fatty acids. 

Omega-6 fatty acids are made up of linoleic acid. They are found in nuts, seeds and vegetable oils, specifically soybean, safflower and corn oil. Experts recommend that 5 to 10 percent of your total caloric intake should come from omega-6 fatty acids.

How do these fatty acids benefit health?

Omega-3 fatty acids thin the blood, reducing the risk for blocked blood vessels, heart attacks and strokes. They also prevent hardening of the arteries, lower triglycerides and help reduce blood pressure.

Omega-6 fatty acids lower cardiovascular disease risk by decreasing total cholesterol, including “bad” cholesterol (LDL—low density lipoprotein). However, by reducing the total cholesterol, omega-6’s also lower “good” cholesterol (HDL—high density lipoprotein), which functions like a sponge and carries “bad” cholesterol and other lipids to the liver for excretion.

The American Heart Association recommends that people who do not have coronary heart disease (CHD) eat a variety of fish, specifically oily fish, at least twice a week. For those with CHD, they recommend one gram of EPA and DHA from oily fish a day. It can be hard to obtain sufficient omega-3 from your diet alone. If so, talk to your physician about adding a fish-oil supplement.

- Rachel Griehs, RD, LDN