Good Food Sources of Omega-3 Fatty Acids
Omega-3 fatty acids are part of a class of fats called polyunsaturated fatty acids (PUFAs). Unlike saturated fats that are commonly found in non-skim dairy products and beef, PUFAs have been linked to many health benefits, such as protecting your heart and your joints.
Health Benefits of Omega-3s
There is some evidence that suggests that omega-3s may:
-
Decrease the risk of heart disease—In one study, people who replaced saturated fats with PUFAs had fewer coronary events (eg, heart attacks ) and fewer deaths due to heart disease. Other studies have suggested this favorable effect on heart disease may be due to the ability of omega-3s to:
- Lower elevated triglyceride levels —High triglyceride levels can contribute to coronary heart disease .
- Decrease the risk of arrhythmia , an abnormality in the rhythm of the heart that can sometimes be life-threatening—Note that the evidence here is contradictory, and there is even some suggestion that omega-3s could increase the risk of harmful arrhythmias in some people. Talk to your doctor before using supplements for this purpose.
- Reduce the blood's tendency to clot—Although blood clotting is a life-saving process in response to a cut or similar trauma, blood clots that occur inside intact blood vessels can contribute to the clogging that occurs with atherosclerosis . By decreasing the tendency to clot, omega-3s make blood thinner and able to flow more easily, which may decrease the risk of heart attack and stroke .
- Reduce the inflammation involved in conditions like rheumatoid arthritis .
- Improve symptoms of depression and other mental health disorders in some individuals, though the evidence is quite limited.
While many of these benefits are probably real, more research is needed to confirm some of the health effects associated with omega-3s. Omega-3s almost certainly have significant benefits on heart health. Sources of omega-3s—fish, nuts, seeds, green leafy vegetables—should be an important part of everyone's diet.
Where You Can Find Omega-3s
Fatty fish is the main source of omega-3 fatty acids. Eating a lot of fish also takes the place of foods high in saturated fats. A good target for omega-3s is 5 grams daily. Remember, though, that some fish contain significant amounts of mercury and may be harmful if eaten in excess.
Canned light tuna, crab, pollock, flounder, oysters, and shrimp are relatively low in mercury and provide quite good levels of omega-3s in a 6-7 ounce serving. Omega-3s are also found in: soybean and canola oils, flaxseed, flaxseed oil, walnuts, and leafy green vegetables.
For more information about mercury levels in fish, visit the US Food and Drug Administration's Food Safety website.
Fish or other food source | Omega-3 content in a 4-ounce serving |
---|---|
Chinook salmon | 3.6 grams |
Sockeye salmon | 2.3 grams |
Albacore tuna | 2.6 grams |
Mackerel | 1.8-2.6 grams |
Herring | 1.2-2.7 grams |
Rainbow trout | 1.0 grams |
Whiting | 0.9 grams |
King crab | 0.6 grams |
Shrimp | 0.5 grams |
Cod | 0.3 grams |
Tofu | 0.4 grams |
Spinach | 0.9 grams |
English walnuts | 6.8 grams |
Wheat germ and oat germ | 0.7 - 1.4 grams |
RESOURCES:
American Dietetic Association
http://www.eatright.org/
American Heart Association
http://www.americanheart.org/
CANADIAN RESOURCES:
Canada's Food Guide
http://www.hc-sc.gc.ca/
Dietitians of Canada
http://www.dietitians.ca/
References:
Duyff RL. The American Dietetic Association's Complete Food & Nutrition Guide . Minneapolis, MN: Chronimed Publishing; 1998.
Fish oil. EBSCO Natural and Alternative Treatments website. Available at: http://www.ebscohost.com/thisTopic.php?marketID=15topicID=114. Updated April 2009. Accessed May 19, 2010.
US Food and Drug Administration. Mercury levels in commercial fish and shellfish. US Food and Drug Administration website. Available at: http://www.fda.gov/Food/FoodSafety/Product-SpecificInformation/Seafood/FoodbornePathogensContaminants/Methylmercury/ucm115644.htm. Updated November 11, 2009. Accessed May 19, 2010.
5/11/2009 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php : Jakobsen MU, O'Reilly EJ, Heitmann BL, et al. Major types of dietary fat and risk of coronary heart disease: a pooled analysis of 11 cohort studies. Am J Clin Nutr. 2009;89:1425-1432.
Last reviewed May 2010 by Brian Randall, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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