What are Omega-3 Fatty Acids

Reviewed by Sarah Klemm, RDN, CD, LDN
What are Omega-3 Fatty Acids

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Research shows that eating two 4-ounce servings of seafood per week may reduce the risk of heart disease and related deaths. Many health professionals attribute this potentially life-saving quality of seafood to the presence of omega-3 essential fatty acids. And, omega-3s are not limited to fish and seafood. They are also found in some vegetable oils, nuts, seeds and soy foods.

Fish contain two important omega-3 fatty acids: EPA (eicosapetaenoic acid) and DHA (docosahexaeonic acid). Although the research is limited, studies show that in patients with known heart disease, higher blood levels of DHA and EPA are associated with a reduction in arrhythmias (irregular heart beat) and fatal heart disease. However, the benefit of eating fish is not clear for those without known heart disease. If you have high blood triglycerides, consuming omega-3 fatty acids may help lower your levels.

Plant-Based Omega-3s

Some plants also contain an omega-3 fatty acid known as ALA (alpha-linolenic acid). You can find it in various oils, nuts, seeds, beans and other sources. Although research is limited, higher intakes of ALA have been shown to reduce risk of heart disease in both those with and without heart disease. Here are tips for getting more plant-based omega-3s:

  • Include vegetable oils that contain omega-3 fatty acids, such as flaxseed oil, walnut oil, canola oil or soybean oil.
  • Add hemp hearts or ground flaxseed to cereals, yogurt and salads. The body isn't able to break down whole flaxseed effectively but grinding them before using helps with absorption.
  • Substitute ground flaxseed for butter or oil when baking. Use 3 tablespoons of ground flaxseed instead of 1 tablespoon of oil.
  • Snack on edamame or walnuts for a snack rich in omega-3 fatty acids.

Omega-3 Supplements

Omega-3 supplements may be beneficial in combating heart disease. Historically, studies have seen up to a 45-percent decrease in risk of death from cardiovascular disease with fish oil supplements containing EPA or DHA. However recent studies have challenged if taking supplements is as effective as consuming food sources. Scientific evidence describing the advantage of omega-3 supplements on heart disease risk for people who don't actually have heart disease is also limited. Consult a health professional to determine if you would benefit from an omega-3 supplement.

Too Much Omega-3?

Given the fact that many of our foods are fortified with omega-3 fatty acids, it is possible to get excess amounts of it if you take additional supplements. The U.S. Food and Drug Administration advises that consumption of more than 3 grams of omega-3 fatty acids per day may cause uncomfortable gastrointestinal symptoms. And, although small, there is a risk of increased bleeding possible when people who take anti-platelet agents or anticoagulants also take fish oil supplements with more than 3 grams of EPA and DHA.

The omega-3 fatty acid content of fish varies. Higher amounts are typically found from sources such as herring, salmon, sardines and trout. Mackerel is also a rich source of omega-3 fatty acids, however, one variety known as king mackerel is also high in mercury and the FDA advises women who are pregnant, nursing mothers and young children to avoid this fish. Atlantic mackerel and Spanish mackerel are both lower mercury alternatives.

In summary, remember to feast on fish at least twice a week and regularly include omega-3-rich plant sources, such as flaxseeds, chia seeds and walnuts, in your diet.

Finally, ask your doctor or a registered dietitian nutritionist to determine if an omega-3 fatty acid supplement would be helpful for you. Omega-3 fatty acid supplements should not be taken without a physician's supervision.

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