Oysters, salmon, and walnuts

Nutrition & Health Info Sheets for Consumers - Omega-3 Fatty Acids

Nutrition & Health Info Sheets contain up-to-date information about nutrition, health, and food. They are provided in two different formats for consumer and professional users. These resources are produced by Dr. Rachel Scherr and her research staff.  Produced by Lisa Huang, Puja KC, Sarah Liu, Taylor Berggren, MS, Anna Jones, PhD, Rachel E. Scherr, PhD, Sheri Zidenberg-Cherr, PhD, Center for Nutrition in Schools, Department of Nutrition, University of California, Davis, 2018.

What are omega-3 fatty acids?

Omega-3 fatty acids are a type of fat that are important to human health. These fatty acids are found mostly in fish and plant oils (1). There are 3 main types of Omega-3 fatty acids: a-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) (2). Consumption of omega-3 fatty acids is an important part of a healthy diet (3).

What are the health benefits of omega-3 fatty acids?

Role of Omega-3 Fatty Acids in Inflammation and Chronic Disease Prevention

Omega-3 fatty acids help maintain body temperature and reduce inflammation. Inflammation is one of the ways the body fights infection and recovers from injury. However, long-term inflammation can lead to serious diseases like heart disease, cancer, and other illnesses (4,5). Omega-3 fatty acids may also help reduce symptoms of asthma, depression, and some autoimmune diseases (6).

Omega-3 Fatty Acid and Pregnancy

Consuming omega-3 fatty acids may improve pregnancy outcomes. An increase in dietary omega-3s during pregnancy has been shown to benefit both the mother and baby. Consuming DHA during pregnancy is important for brain and eye development of the baby and has been shown to lower the severity of cold symptoms in infants (7).

What are the current recommendations for consumption of omega-3 fatty acids?

The Dietary Guidelines for Americans 2015-2020 recommends 450-500 milligrams of omega-3 fatty acids per day (2,3). Those with coronary heart disease should consume 1 gram of omega-3 fatty acid per day, preferably from fatty fish (9).

What is the omega-3 fatty acid content of commonly consumed fish?

Some common seafood items with omega-3 fatty acids are salmon, tilapia, oyster, herring, and canned tuna. Examples of plant oils and nut/seeds that are good sources of omega-3 fatty acids include: flaxseed oil, canola oil, walnut oil, canola oil, olive oil, flaxseed, walnuts, pistachio, pumpkin and squash seeds, and pine nuts (8).

Table 1: Omega-3 fatty acid content of commonly consumed seafood
Fish (Raw) ALA (mg/3oz) EPA (mg/3oz) DHA (mg/3oz)
Catfish 46 14 48
Clams 13 37 54
Cod 0 19 38
Crab 7 24 0
Flounder or Sole 15 93 117
Grouper 8 23 187
Halibut 9 56 109
Herring 88 603 733
Lobster 37 87 58
Mahi Mahi 4 17 75
Orange Roughy 3 13 3
Oyster 139 230 300
Red Snapper 3 43 221
Salmon 126 733 938
Shrimp 2 26 26
Tilapia 38 6 100
Tuna, canned 1 8 56

What is the omega-3 fatty acid content of commonly consumed plant oils, nuts, and seeds?

Examples of plant oils and nut/seeds that are good sources of omega-3 fatty acids include: flaxseed oil, canola oil, walnut oil, canola oil, olive oil, flaxseed, walnuts, pistachio, pumpkin and squash seeds, and pine nuts (8).

Table 2: Omega-3 fatty acid content of commonly consumed plant oils
Plant Oils ALA (mg/1 tbsp) EPA (mg/1 tbsp) DHA (mg/1 tbsp)
Olive Oil 46 14 48
Soybean Oil 923 0 0
Canola Oil 1279 0 0
Corn Oil 158 0 0
Walnut Oil 38 6 100
Flaxseed Oil 6703 0 0
Coconut Oil 3 0 0
Table 3: Omega-3 fatty acid content of commonly consumed nuts and seeds
Nuts/Seeds ALA (mg/1 Cup) EPA (mg/1 Cup) DHA (mg/1 Cup)
Brazil nuts 24 0 0
Pine nuts 151 0 0
Pistachio 261 0 0
Walnuts, black 3,346 0 0
Almonds 4 0 0
Peanuts 37 0 0
Pumpkin and Squash Seeds 155 0 0
Sunflower Seeds 103 0 0
Flaxseed 38,326 0 0

What are the current recommendations for fish consumption?

The American Heart Association recommends at least 12 ounces of different types of fatty fish each week. One serving of fish is about 3 ounces (9).

Who is at risk for mercury exposure?

Eating fish with higher levels of mercury can expose you to mercury. Long-term mercury exposure can lead to many negative health effects, including abnormal brain growth in babies and damage to the heart and kidneys in children.10,11 Women who are or may become pregnant, breastfeeding mothers, young children and teens are at greatest risk (10).

The United States Food and Drug Administration and the United States Environmental Protection Agency encourage these individuals to avoid eating swordfish, tilefish, king mackerel, and shark, the four fish with the most mercury. Instead, one should choose seafood low in mercury. Scallops, shrimp, clams, salmon and crab are commonly consumed types of seafood in the U.S. that are low in mercury (12).

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  1. Jenkins DJ, Josse AR. Fish oil and omega-3 fatty acids. Canadian Medical Association Journal. 2008;178(2):150-150. doi:10.1503/cmaj.071754.
  2. Vannice G, Rasmussen H. Position of the Academy of Nutrition and Dietetics: Dietary Fatty Acids for Healthy Adults. Journal of the Academy of Nutrition and Dietetics. 2014;114(1):136-153. doi:10.1016/j.jand.2013.11.001.
  3. Dietary Guidelines for Americans 2015–2020 8th Edition. Chapter 4 - 2008 Physical Activity Guidelines. http://health.gov/dietaryguidelines/2015/guidelines. Accessed September 30, 2016.
  4. Minihane AM, Vinoy S, Russell WR, et al. Low-grade inflammation, diet composition and health: current research evidence and its translation. British Journal of Nutrition. 2015;114(07):999-1012. doi:10.1017/s0007114515002093.
  5. Yates CM, Calder PC, Rainger GE. Pharmacology and therapeutics of omega-3 polyunsaturated fatty acids in chronic inflammatory disease. Pharmacology & Therapeutics. 2014;141(3):272-282. doi:10.1016/j.pharmthera.2013.10.010.
  6. Office of Dietary Supplements - Omega-3 Fatty Acids. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/. Accessed October 20, 2016.
  7. Imhoff-Kunsch B, Stein AD, Martorell R, Parra-Cabrera S, Romieu I, Ramakrishnan U. Prenatal Docosahexaenoic Acid Supplementation and Infant Morbidity: Randomized Controlled Trial. Pediatrics. January 2011. doi:10.1542/peds.2010-1386.
  8. Welcome to the USDA Food Composition Databases. Food Composition Databases Show Foods -- Oil, soybean, salad or cooking. https://ndb.nal.usda.gov/ndb/. Accessed October 20, 2016.
  9. Kris-Etherton PM. Fish Consumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular Disease. Circulation. 2002;106(21):2747-2757. doi:10.1161/01.cir.0000038493.65177.94.
  10. Fish, levels of mercury and omega-3 fatty acids. American Heart Association. http://www.heart.org/HEARTORG/HealthyLiving/HealthyEating/HealthyDietGoals/Fish-and-Omega-3- Fatty-Acids_UCM_303248_Article.jsp. Updated Oct 6, 2016. Accessed Oct 20, 2016.
  11. Bose-Oreilly S, Mccarty KM, Steckling N, Lettmeier B. Mercury Exposure and Childrens Health. Current Problems in Pediatric and Adolescent Health Care. 2010;40(8):186-215. doi:10.1016/j.cppeds.2010.07.002.
  12. Center for Food Safety and Applied Nutrition. Metals - Mercury Levels in Commercial Fish and Shellfish (1990-2012). U S Food and Drug Administration Home Page. http://www.fda.gov/Food/FoodborneIllnessContaminants/Metals/ucm115644.htm. Accessed October 20, 2016.

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