Walgreens The Thread

What are omega-3 fats?

By Michelle Katz, MS, RD, CDCES May 22, 2023 • 6 min

It’s a myth that all fats are bad for you. Some fats, called essential fatty acids, are vital to your health and well-being. Since your body can’t produce them on its own, these key nutrients must come from the foods that you eat. Some people struggle to get enough of one group of essential fatty acids called omega-3s.

What is omega-3?

Found naturally in foods and available in supplements, omega-3 fatty acids are polyunsaturated fats. They help form the membranes that surround cells and play a role in blood clotting, controlling inflammation and even regulating heartbeat. There are three main kinds of omega-3s: DHA, EPA and ALA.

What is DHA?

Docosahexaenoic acid, or DHA, is known as a long-chain omega-3. In nature, algae naturally produce this essential fatty acid. When fish and other sea life consume it, DHA builds up in their tissues. Consuming fish is one of the best ways to get DHA from your diet.

What is EPA?

Eicosapentaenoic acid, or EPA, is another long-chain essential fatty acid. Like DHA, this omega-3 comes from algae and is most commonly found in fish and other marine life.

What is ALA?

Alpha-linolenic acid, or ALA, is known as a short-chain essential fatty acid. Certain plants contain this omega-3 fatty acid.

What are some sources of omega-3?

Most people in the U.S. get the majority of their essential fatty acids as ALA. The body can convert ALA into EPA and then into DHA. However, only small amounts of DHA and EPA are manufactured in this way. As a result, people may not get enough of the long-chain omega-3s through diet alone. 

Here’s how you can get omega-3 fatty acids:


In general, consuming whole foods is the best way to get essential fatty acids. Some foods high in omega-3s include:

  • Albacore tuna
  • Chia seeds
  • Edamame
  • Mackerel
  • Salmon
  • Sardines
  • Soybeans
  • Tofu
  • Trout
  • Walnuts

Plant oils, like canola and soy oil, are also good sources of ALA. Flaxseeds and flaxseed oil offer the highest concentration of ALA per serving and are a good option for vegans and vegetarians who want to increase their intake of omega-3s without consuming animal products.

Many of the foods rich in omega-3s are a part of the Mediterranean diet, an eating plan that healthcare providers sometimes recommend for heart health. With this diet, most of your daily calories come from vegetables, fruits, beans, lentils, nuts and whole grains. The Mediterranean diet promotes cooking with and consuming plenty of olive oil, as well as eating a moderate amount of omega-3-rich fish, cheese and yogurt.


If you find it difficult to consume enough foods rich in omega-3 essential fatty acids, fish oil and omega supplements may help bridge the dietary gap. Types of omega-3 supplements include:

  • Fish oils: Fish oils are one of the best-known omega-3 fatty acid supplements. Although dosages and formulas vary, the average product provides 180 mg of EPA and 120 mg of DHA per 1,000 mg of fish oil.
  • Krill oils: Omega-3 krill oil supplements come from tiny marine animals that look similar to shrimp. Some studies indicate that it may be easier for the body to absorb and use the DHA and EPA in krill oil than the omega-3s in fish oil. However, more research is needed.
  • Cod liver oil: Sourced from cod fish, cod liver oil supplements deliver EPA and DHA plus vitamins A and D.
  • Stand-alone supplements: If you want to boost your intake of just one omega-3, you can choose a stand-alone product. Top brands produce EPA, ALA and DHA supplement products in various doses and forms.
  • Plant oils: Vegans and vegetarians can find plant-based supplements that contain oil derived from algae, flaxseeds and other plant sources. Check the label to learn how much EPA and DHA these supplements may have.

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

Based on clinical studies, evidence suggests that omega-3s derived from supplements and food may:

  • Support heart health and reduce the risk of irregular heartbeat and heart disease
  • Aid in a baby’s growth and development when consumed by pregnant and breastfeeding women
  • Assist with brain function
  • Reduce levels of triglycerides, a type of fat that can be unhealthy at high levels in the body
  • Lower the likelihood of developing age-related macular degeneration (AMD), an eye disease that can lead to blindness
  • Reduce symptoms of dry eye disease
  • Ease symptoms of rheumatoid arthritis (RA), an autoimmune disease that occurs when the immune system attacks the joints

According to the National Institutes of Health (NIH), more research is necessary to determine whether an omega-3 supplement like fish oil benefits people with other medical conditions.

How much omega-3 should you take?

The U.S. Department of Agriculture hasn’t published recommendations for EPA and DHA fatty acids. How much you need depends on a variety of factors, including your age, sex, medical history and dietary habits. Your healthcare provider can help you decide which type of omega-3 supplement is right for you and recommend the right dosage.

Updated May 2023.

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