Now that we know omega-3 fatty acids are key to good health, let's explore how to get them through our eating patterns...
How Many Omega-3s Do I Need?
There isn’t enough scientific evidence to establish a Recommended Dietary Allowance (RDA) for omega-3s, but there is an Adequate Intake (AI), which is based on the omega-3 intakes in healthy populations. Even though DHA and EPA are important for health, the AI applies only to ALA, because it is the only omega-3 that our body doesn’t make and which must be obtained from food.
Here's a chart of the AI for ALA omega-3 fatty acid needs depending on age, sex, and contributing life events...
Food Sources of Omega-3 Fatty Acids:
Flaxseed oil contains the highest amount of ALA at 7.26 grams (g) per tablespoon. Other good sources of ALA include chia seeds (5g/ounce), English walnuts (2.5g/ounce), and canola oil (1.2g/tablespoon).
Salmon and herring contain the highest amounts of DHA and EPA with 3 ounces of cooked wild Atlantic salmon containing 1.22g DHA and 0.35g EPA. 3 ounces of cooked herring contain 0.94g DHA and 0.77g EPA.
Other good sources of DHA and EPA include sardines (.74g DHA and .45g EPA per 3 ounces), mackerel (.59g DHA and .43g EPA per 3 ounces cooked), canned salmon (.63g DHA and .28g EPA per 3 ounces) and rainbow trout (.44g DHA and .4g EPA per 3 ounces cooked).
Seafood may be contaminated with mercury, a toxic metal that is commonly found in large ocean fish. Types of seafood that are higher in EPA and DHA and lower in mercury include salmon, anchovies, herring, shad, sardines, Pacific oysters, trout, and Atlantic and Pacific mackerel (not king mackerel, which is high in methyl mercury). The current recommendation is to choose 8-12 ounces of seafood that's lower in mercury per week.
Some foods, such as certain brands of eggs, yogurt, juices, milk, and soy beverages, are fortified with DHA and other omega-3s.
What about Omega-3 Supplements?
There are several different types of omega-3 fatty acid supplements available, including fish oil, krill oil, cod liver oil, and oil made from algae.
There is no standard omega-3 supplement, and the amount of ALA, DHA, and EPA can vary quite a bit across brands, so it's important to read the supplement label.
While omega-3 fatty acids are important for a healthy immune system, too high of an intake can be harmful. Doses higher than 900mg/day of EPA plus 600mg/day DHA might actually reduce immune function. Higher doses of omega-3 supplements might also decrease blood clotting time. The FDA recommends not exceeding 3g per day of EPA and DHA combined, with up to 2 g per day from dietary supplements. Anyone who takes anticoagulants like Warfarin should check with their physicians before using omega-3 supplements.
Our Omega-3 Recommendations:
- Include seafood higher in omega-3s such as salmon or mackerel in your food choices 2-3 times per week.
- Use olive or canola oil as your primary cooking oils and in salad dressings.
- Sprinkle salads or oatmeal with ground flaxseeds, chia seeds, or walnuts.
- Only use omega-3 supplements on the advice of your physician.
By Lynn Grieger, RDN, CDE, CPT, CHWC
- National Institutes of Health. Office of Dietary Supplements. Omega-3 Fatty Acids Fact Sheet for Professionals. https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/ updated 10-1-20. Accessed 12-24-20.
- Gutiérrez S, Svahn SL, Johansson ME. Effects of Omega-3 Fatty Acids on Immune Cells. Int J Mol Sci. 2019;20(20):5028. Published 2019 Oct 11. doi:10.3390/ijms20205028.
- Kiecolt-Glaser JK, Glaser R, Christian LM. Omega-3 fatty acids and stress-induced immune dysregulation: implications for wound healing [published correction appears in Mil Med. 2016 Sep;181(9):1165]. Mil Med. 2014;179(11 Suppl):129-133. doi:10.7205/MILMED-D-14-00167.
- U.S. Food and Drug Administration. Advice About Eating Fish. https://www.fda.gov/food/consumers/advice-about-eating-fish content current as of 12-29-20; accessed 12-29-20.
Stephanie Ronco has been editing for Food and Health Communications since 2011. She graduated from Colorado College magna cum laude with distinction in Comparative Literature. She was elected a member of Phi Beta Kappa in 2008.