Omega-3s Update

October 31st, 2018

by Karen Buch RDN, LDN

When it comes to dietary fats, 81 percent of the people know there are good and bad fats, but only 19 percent know the difference. It is helpful to know which types of fats to avoid and which types of fats to eat more often. For example, it is important to reduce saturated fat intake to less than 10 percent of calories per day and shift food choices toward polyunsaturated fats instead. In addition, the majority of Americans need to boost their intake of “good fats” omega-3s, based on observational NHANES data showing more than 90 percent of U.S. adults do not consume enough.  1

What are Omega-3s?

Omega-3s are fatty acids in the human diet. Essential fatty acids, necessary for normal health and development, must be supplied through diet or supplementation. Alpha-linoleic acid (ALA) is an essential fatty acid and the precursor to both eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)—although the body converts very little ALA (just 1 to 5 percent) to EPA, with an even smaller amount converting to DHA. All of these fatty acids (ALA, EPA, DHA) are omega-3s.

ALA omega-3s
ALA omega-3s can be found in walnuts, flaxseeds, chia seeds, canola oil, pecans and soybean oil.  The adequate intake(AI) for ALA is set at 1.6 and 1.1 grams per day for men and women respectively.


Dietary Sources * ALA Omega-3s
1 Tbsp Whole Ground Flaxseed Meal 1.2 g
1 Tbsp Canola Oil 1.3 g
1 Tbsp Flaxseed Oil 7.3 g
1 Tbsp Chia Seeds 2.1 g
1 Ounce Walnuts 2.5 g
1 Ounce Pecans 0.5 g

*not a complete list

Are Nuts Rich in ALA Omega-3s?
Walnuts are the only nuts significantly high in ALA omega-3s, supplying 2.5 grams ALA per ounce of walnuts (equivalent to a ¼ cup or about a handful of 12 to 14 halves) supplying 190 calories and 18 grams of total fat—the majority of which is polyunsaturated.

Long-chain EPA and DHA omega-3s can be found in fatty fish, shellfish and fish oil supplements.  Research indicates people who eat seafood one to four times a week are less likely to die from heart disease. Similarly, the Dietary Guidelines for Americans 2015-2020 recommends adults eat 8 or more ounces of a variety of seafood (fish or shellfish) per week. Consider (2) 3.5-ounce servings of non-fried fish or about ¾ cup of flaked fish every week with an emphasis on oily fish richest in EPA + DHA.
A specific AI has not been established for EPA + DHA. Generally, experts recommend striving for 250 to 500 mg EPA + DHA per day. GOED (Global Organization for EPA and DHA) recommends 500 mg EPA per day for general health and higher quantities for specific life stages or health conditions. The American Psychiatric Association recommends 1,000 mg EPA + DHA per day for people with mood, impulse control or psychotic disorders. Do not supplement with more than 3 g omega-3s via fish oil capsules unless under a physician’s care, as such levels may cause excessive bleeding.

Which fish are the richest in DHA & EPA Omega 3s?

Fish Richest in EPA + DHA Omega 3s (per 4 ounce cooked portion)
>1000 mg 500-1000 mg 250-500 mg <250 mg
Anchovies Alaskan Pollack Catfish Cod
Herring Barramundi Clams Crayfish
Mackerel (Atlantic, Pacific) Crab Flounder/Sole Haddock
Oysters (Pacific) Mussels Grouper Lobster
Sablefish (black cod) Salmon (Chum, Pink & Sockeye) Halibut Mahi Mahi
Salmon (Atlantic, Chinook, Coho) Sea Bass Mackerel (King) Shrimp
Sardines (Atlantic, Pacific)              Squid Oysters (Eastern) Scallops
Swordfish Tilefish Perch Tilapia
Trout Tuna (Albacore) Rockfish Tuna (Yellowfin)
Walleye Snapper
Tuna (skipjack, canned)

Source: Seafood Nutrition Partnership

Which is better ALA or DHA + EPA?
Both plant-based ALA and marine-based EPA + DHA omega-3s appear to provide significant health benefits. According to a 2014 literature review, ALA may be as effective in reducing risk of cardiovascular disease (CVD) as marine-derived omega-3s.2

In addition, the landmark PREDIMED study (of more than 7,000 subjects) found that consuming omega-3s from plant-based sources may reduce risk of all-cause mortality, whereas marine-derived omega-3s from fatty fish may reduce the risk of heart-related fatalities. The greatest protective effects from total mortality were observed in diets that included BOTH plant-based and marine-derived omega-3s, appearing to act in synergy.

EPA + DHA have been tested extensively, including more than 3,700 human clinical trials. Beyond reducing cardiovascular risk, studies show omega-3s can help also reduce risk of cognitive decline, Alzheimer’s disease and dementia; contribute to infant and neurodevelopment; reduce risk of certain cancers and help prevent age-related macular degeneration, among other emerging health benefits. 3

Testing Omega-3 Levels
Consumers can request omega-3 testing during routine blood work (it is not typically part of routine blood tests). Various home testing kits are also available to check omega-3 levels, such as OmegaQuant Omega-3 Index. For about $39.99, one can easily measure omega-3 status. Simply collect a drop of blood, mail the sample and receive results within 2 to 4 weeks. A range of 8-12% is associated with better overall health. As a more personalized approach to nutrition continues to broaden, individuals can use such testing to adjust dietary intake of omega-3s and fish oil supplements to achieve optimal omega-3 status and maximize personal health and well-being.

  1. Papanikolaou Y, Brooks J, Reider C, Fulgoni VL: U.S. adults are not meeting recommended levels for fish and omega-3 fatty acid intake: results of an analysis using observational data from NHANES 2003–2008. Nutr J. 2014, 13: 31-10.1186/1475-2891-13-31.
  2. J. A. Fleming, P. M. Kris-Etherton. The Evidence for Alpha-Linolenic Acid and Cardiovascular Disease Benefits: Comparisons with Eicosapentaenoic Acid and Docosahexaenoic Acid. Advances in Nutrition: An International Review Journal, 2014; 5 (6): 863S DOI:10.3945/an.114.005850

Karen Buch, RDN, LDN is a Central Pennsylvania-based Registered Dietitian Nutritionist who promotes the healthy enjoyment of food and helps consumers better understand the connection between food, nutrition and health. As owner of Nutrition Connections LLC, Karen provides a variety of food and nutrition communications consulting services to the food industry nationwide. Connect with her on the web at or follow her on facebook: Nutrition Connections LLC, instagram:@karenbuch1, twitter: @karenbuch or subscribe to her blog: Food News & Reviews.



Posted by: Deanna Segrave-Daly

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