It is well established that omega-3 fatty acids are beneficial to health, but knowing they are good for you is different than understanding why, or what to eat. Here are five things you should know about these essential fatty acids:

How do omega-3 fatty acids benefit health?

Omega-3 fatty acids reduce inflammation in the body. Inflammation is linked to chronic diseases, including heart disease, some cancers, and arthritis. While the research supporting a reduced risk for heart disease is the most established, some research has shown that the fatty acids may also reduce the risk of stroke, diabetes, and cognitive decline.

Are there different types?

Yes. Omega-3 fatty acids are different depending on the food source. Alpha-linolenic acid (ALA) is a short-chain fatty acid that can be found in plant foods. Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are long-chain fatty acids found in fish.

How does the body use the omega-3 fatty acids we eat?

The body must convert the short-chain ALA to the long-chain DHA and EPA for it to be useful. Unfortunately, the rates of conversion are not high. According to the Linus Pauling Institute at Oregon State University, young men can convert 8% of ALA to EPA, and only 0-4% to DHA. Young women convert 21% of ALA to EPA, and 9% to DHA. The difference in these conversion rates is attributed to the higher levels of estrogen in women. Don’t let these low numbers discourage you from eating vegetarian sources for omega-3 fatty acids. Researchers still consider plant foods a beneficial source for omega-3s despite the low conversion rates.

What are the best food sources?

A variety of seeds, vegetables, and oils contain ALA. Good seed choices are flaxseeds, chia seeds, pumpkin seeds, and sesame seeds. Tahini, which is a paste made from sesame seeds, is also a good choice. The oils from these seeds (e.g. flaxseed oil) also contain the beneficial omega-3s. Kale, spinach, Brussels sprouts, cauliflower, and purslane are vegetable sources for ALA. Increase your intake of cold-water, fatty fish for DHA and EPA. Choose wild salmon, mackerel, halibut, sardines, albacore tuna, herring, or lake trout. According to the Natural Resources Defense Council, herring, North Atlantic and Chub mackerel, salmon, and freshwater trout contain the least amounts of mercury.

How much do I need?

Due to the role of omega-3 fatty acids in preventing heart disease, the American Heart Association (AHA) provides recommendations for intake. The AHA recommends that healthy adults consume at least two servings of fatty fish a week. A 2-to-4 oz serving of fish provides approximately 1 g of omega-3 fatty acids. In addition, the AHA recommends including plant sources of omega-3 fatty acids in your diet such as tofu, walnuts, and flaxseeds.

Lori Rice, M.S., is a nutritional scientist and author with a passion for healthy cooking, exercise physiology, and food photography.