What Omega-3 Fatty Acids Do for Your Health, According to a Dietitian

Omega-3 fatty acids (omega-3s) are essential fats your body needs for various functions. They are one of the two main types of polyunsaturated fatty acids (along with omega-6 fatty acids), which is considered a "healthy fat."

Omega-3s are found in both animal- and plant-based foods as well as dietary supplements. They are considered "essential" because they must be obtained through the diet. Your body can't make omega-3 fatty acids on its own. Omega-3s are vital to heart health, brain health, fetal and infant development, cell structures, and more.

What Do Omega-3 Fatty Acids Do?

Omega-3 fatty acids have been linked to a variety of nutrition and health benefits. Your body needs them to support certain functions, such as cell integrity, brain development, energy, and other important processes.

Research shows that omega-3s may lower the risk of heart disease, cancer, arthritis, and other chronic conditions.

• Heart health: Research has found that the use of omega-3 fatty acids (especially eicosapentaenoic acid [EPA]) was associated with reduced cardiovascular mortality and other outcomes.
• Cholesterol and blood pressure: Recent research shows that taking 2–3 grams (g) of docosahexaenoic acid (DHA) and EPA per day may reduce blood pressure and triglycerides and increase high density lipoprotein (HDL) cholesterol ("good" cholesterol). These effects are thought to reduce the overall risk of heart disease.
• Brain function: According to one review, omega-3 fatty acids may increase oxygen and blood circulation to the brain, leading to improved mental performance. Studies have also found links between omega-3 supplementation and improved memory and learning, as well as protection against age-related cognitive decline.
• Depression: Some research shows that omega-3s may also help reduce symptoms of depression when used alongside antidepressants. However, more research is needed in this area.
• Osteoarthritis (OA): Preliminary research shows that omega-3 fatty acids may help treat OA, a degenerative joint disorder. Omega-3s are thought to help reduce OA-related inflammation and pain and slow the breakdown of cartilage seen in the disorder. Researchers feel that more studies are needed in this area, though.
• Rheumatoid arthritis (RA): According to one review, increased consumption of omega-3 fatty acids from mainly fish sources decreases pain and other symptoms of RA.
• Skin health: Studies show that both oral and topical omega-3s may improve skin issues like inflammation, hyperpigmentation, dry skin, wounds, and itching.
• Aid to cancer treatment: Researchers from one review found that omega-3s may aid standard cancer treatments and help reduce possible side effects, such as inflammation, pain, poor appetite, and depression. According to the review, omega-3s are crucial to cell signaling and, thus, may influence certain cell pathways involved in the cancer process.
• Cancer prevention: Some research suggests that the anti-inflammatory properties of omega-3 fatty acids may also help with the prevention of certain cancers, including breast cancer and colorectal cancer. However, more research is needed.
• Age-related macular degeneration (AMD): Studies have shown a link between higher omega-3 fatty acid intake and a lower risk of developing AMD. Research also suggests that omega-3s may slow the progression of AMD. However, two large-scale human trials found that omega-3 supplementation did not significantly affect AMD development or progression.

Omega-3s may also help reduce the risk of the following:

• Type 2 diabetes
• Stroke
• Asthma
• Inflammatory bowel disease (IBD)
• Mental decline

Types

There are three types of omega-3 fatty acids:

• Eicosapentaenoic acid (EPA)
• Docosahexaenoic acid (DHA)
• Alpha-linolenic acid (ALA)

In the body, small amounts of ALA are converted to EPA and DHA. However, it's recommended that you still get plenty of EPA and DHA from your diet.

All three omega-3 fatty acids are important to your health, with roles in cell structure and integrity, fetal brain development, infant growth, inflammation, joint health, heart health, and cognitive ability.

Food Sources

You can find omega-3 fatty acids in a variety of foods, including both animal and plant foods. EPA and DHA are mostly found in animal foods, while ALA is primarily found in plant-based foods and oils.

Fatty fish is considered the best source of omega-3s. Animal foods that contain omega-3 fatty acids include:

• Herring
• Mackerel
• Oysters
• Salmon
• Sardines
• Trout
• Tuna

Some plant sources of omega-3s in order of abundance are:

• Flaxseed and flaxseed oil
• Chia seeds
• Walnuts
• Canola oil
• Soybean oil
• Edamame
• Certain types of beans, such as kidney beans

Some foods and drinks, such as eggs, yogurt, juice, milk, soy milk, and infant formula, may also be fortified with omega-3 fatty acids.

Omega-3 Supplements

A food-first approach—that is, getting the nutrients your body needs from food before trying supplements—is always recommended.

Research suggests that omega-3-rich foods (like fatty fish) provide more benefits than dietary supplements. However, supplements are sometimes necessary. For example, a healthcare provider may recommend taking an omega-3 fatty acid supplement for a specific health condition.

Omega-3 supplements have been linked to health benefits, like reduced triglycerides and RA symptom relief.

You can find both animal-based and plant-based omega-3 supplements that are made from:

• Algal oil (omega-3 supplement from algae)
• Cod liver oil
• Fish oil
• Flaxseed oil
• Krill oil

Using omega-3 supplements, especially in excess, may cause unpleasant side effects. Fortunately, these are usually mild. Possible side effects include:

• Bad breath
• Foul-smelling sweat
• Headache
• Heartburn
• Nausea
• Diarrhea

To lower the risk of side effects, use omega-3 supplements only as directed.

How Much Omega-3 Do I Need?

Adult males should aim for 1.4 g of omega-3s daily, while adult females need about 1.1 g. Those who are pregnant or breastfeeding need more omega-3 fatty acids per day, 1.4 g and 1.3 g, respectively.

There are no strict dosage recommendations for omega-3 fatty acid supplements. However, the Food and Drug Administration (FDA) recommends using no more than 5 g of omega-3 fatty acids daily.

Safety Considerations

Certain precautions should be taken before using omega-3 fatty acid supplements.

Some people may be allergic to ingredients found in omega-3 supplements. People with a fish allergy should not use omega-3 supplements derived from marine sources.

Always check a supplement's ingredients list for known allergens. Seek immediate medical attention if you have a severe allergic reaction (itching, hives, shortness of breath) to an omega-3 supplement.

People with certain health conditions should check with a healthcare provider before using omega-3 fatty acid supplements. Talk with a healthcare provider if you have the following:

• Atrial fibrillation
• Diabetes
• Liver disease
• Pancreatic disease
• Thyroid disease

People who are pregnant or breastfeeding should also check with a healthcare provider regarding the safety of omega-3 supplements.

Additionally, omega-3 fatty acids may interact with various medications, causing the medication to not work properly. Possible interactions include:

• Anticoagulants
• Antiplatelets
• Beta-blockers
• Diuretics
• Estrogen-containing birth control
• Estrogen replacement therapy
  

It's best to be cautious and talk with a healthcare provider before starting any new dietary supplement. This is especially true if you have health conditions or take prescription medications.

Summary

Omega-3 fatty acids are polyunsaturated fats that your body needs for cell integrity, brain development, energy, and other important processes. Your body cannot make omega-3s, which means you have to get them through your diet.

Research shows that the three types of omega-3 fatty acids, EPA, DHA, and ALA, may be beneficial for heart health, brain function, joint health, and skin health. EPA and DHA are found in fatty fish and a few other animal foods, while ALA is found in plant foods.

Some people are recommended to take an omega-3 supplement for a health condition or other reason. However, side effects are possible and omega-3 supplements may not be right for everyone. Talk with a healthcare provider to learn more about omega-3 fatty acids.