What Is the Right Omega-3 Dosage for Adults? (2024)

A 3-ounce serving of fatty fish contains 1.2 to 1.8 grams (g) of DHA + EPA. Omega-3 supplements are available in a range of dosages, but two soft gels often provide 1.2 to 1.4 g of omega-3s.

Supplementation is beneficial for specific populations. DHA has been studied for its role in supporting the fetus's brain and eye development in the uterus of pregnant women. Researchers found that women who were low in DHA and supplemented daily with 1,000 milligrams (mg), equivalent to 1 g, compared with 200 mg, experienced lower rates of preterm birth.

However, more isn't always better. One study found people who took more than 1,000 milligrams per day (mg/day) of omega-3s were at an increased risk of atrial fibrillation (AFib), a common heart arrhythmia (when the heart beats irregularly or at an unhealthy speed). This research conflicts with prior research that suggests the intake of omega-3 reduces atrial fibrillation.

The research suggests there could be a dosage effect: Less than 1,000 mg/day is associated with a reduced risk of AFib, and more than 1,000 mg/day is associated with a higher risk. More studies are needed to determine a dosing effect.

Benefits of Omega-3s

Omega-3s are essential fatty acids that must be obtained through diet to reach optimal intake. Although the body can convert ALA (plant-based omega-3) to DHA and EPA in small quantities, dietary intake and sometimes supplementation are needed.

Omega-3s help with various functions in your heart, lungs, immune system, and endocrine system, as well as in hormone production. These nutrients have been studied for their role in health at every stage of life.

Heart Disease

The use of omega-3 supplements in people with heart disease has been studied for many years with mixed results.

A 2019 systematic review and meta-analysis of13 clinical trials, including 127,477 participants. The omega-3 doses ranged from 0.376 to 4 g per day, and the mean treatment period was five years.The study authors concluded that omega-3 supplementation reduces the risk of:

• Heart attack
• Coronary heart disease death
• Total coronary heart disease (involves the heart)
• Cardiovascular disease death
• Total cardiovascular disease (involves the blood vessels)

However, a 2018 review of 10 clinical trials, including 77,917 participants, showed that omega-3 supplements had no significant association with fatal or nonfatal coronary heart disease. It also didn't impact any major vascular events, such as heart attack, stroke, or arrhythmia.

Although this remains controversial, the American Heart Association (AHA) recommends approximately one gram per day of EPA plus DHA (preferably from oily fish) for people with existing coronary heart disease. They also state supplements could be considered under the direction of a physician.

Blood Pressure

There is some evidence that consuming omega-3 fatty acids in food or dietary supplements may reduce the risk of high blood pressure. According to the AHA, a review of dozens of studies suggests the optimal amount of omega-3 fatty acids to lower blood pressure is about 3 grams daily.

However, more research is needed. Talk with your healthcare provider before taking omega-3 supplements for blood pressure.

Triglycerides

High doses of omega-3 supplements have been shown to reduce levels oftriglycerides.

A 2020 Cochrane Review of 86 randomized controlled trials with 162,796 participants found that 0.5 g/day to more than 5 g/day of omega-3 supplementation for 12 to 88 months reduced serum triglyceride levels by about 15%.

For people with hightriglycerides, the AHA recommends a dose of 4,000 mg per dayof omega-3s.

Brain Health

Numerous studies have examined the effects of maternal seafood and omega-3 intakes on infant cognitive development and other health outcomes. The 2015–2020Dietary Guidelines for Americansrecommend pregnant or breastfeeding people consume 8–12 ounces of seafood per week, choosing from varieties higher in EPA and DHA and lower in mercury, such as salmon, herring, sardines, and trout.

The American Academy of Pediatrics recommends that breastfeeding people consume 200–300 mg of DHA per day by consuming one to two servings of fish per week to guarantee sufficient DHA in breast milk.

Cancer

Multiple studies have suggested that omega-3 fatty acid intake may be associated with a protective effect on cancer risk, but this remains controversial. A review of 15 clinical studies concluded there is weak evidence of an association between omega-3 fatty acid intake and risk of cancer of the liver, breast, prostate, and brain.

In addition, an association is not the same as causation. Further research is needed to confirm whether omega-3 fatty acid intake affects cancer risk.

Dry Eyes

A study of people who experience dry eyes from extensive screen time found that supplementing with 720 mg EPA plus 480 mg DHA for six months improved dry eye symptoms compared to the placebo group.

However, a review that included 34 studies involving 4,314 adult participants from 13 countriesstated the findings suggest a possible role for omega-3 supplementation in managing dry eye disease, but the evidence is uncertain and inconsistent.

More research is needed.

Memory

Omega-3 intake and cognition have been studied in adults with mixed results. A meta-analysis including 15 studies demonstrated that DHA supplementation greater than 580mg/day significantly improved memory in healthy adults (18 to 90years old) with or without mild memory complaints.

However, two trials that supplemented participants aged 18 to 70years old with 850 mg and 1,000 mg of DHA for 12weeks did not show any effects on cognition.

Omega-3 Sources: Foods and Supplements

The best way to get omega-3 fatty acids is by eating 3 ounces of fatty fish at least twice weekly for optimal EPA and DHA levels. Supplements containing EPA and DHA are also available. However, they are most likely sourced from fish.

The omega-3 fatty acid, ALA, is found in plant-based sources, as well as in supplement form. Specific types of algae and seaweed may contain some EPA and DHA.

Some plant-based sources of omega-3 fatty acids include:

• Flaxseeds
• Walnuts
• Chia seeds
• Hemp seeds
• Edamame (soybeans in the pod)
• Plant-based oils (flaxseed oil, canola oil, soybean oil)
• Fortified products (juices, soy beverages, plant-based milk, margarine, cereal, oatmeal)

Animal-based sources of omega-3 fatty acids include:

• Fish (salmon, mackerel, tuna, herring, sardines)
• Meat (beef, lamb, mutton, with higher concentrations in grass-fed varieties)
  
• Fortified foods (eggs, yogurt, milk)

Supplements are typically made from fish oil derived from oily fish, krill oil, cod liver oil, and algal oil (a vegan form).

A minimum intake of 1,000 mg of DHA and EPA omega-3 fatty acids is optimal for most people.

There is no best time to take omega-3s unless you experience digestive issues or take certain medications that might interfere with intake. If you are experiencing increased belching, you may want to consume omega-3s with your largest meal to potentially lessen these effects.

How Many Omega-3s Are Too Much?

Unless a healthcare provider indicates otherwise, no more than 5 g of EPA and DHA from supplements are recommended daily. The American Heart Association recommends the prescription use of EPA plus DHA or EPA-only of up to 4 g per day for people with elevated triglycerides. A healthcare provider should supervise this dosage.

Talk to your healthcare provider before taking omega-3 supplements if you take blood pressure medication or blood thinners like Jantoven (warfarin).

As mentioned before, one study found people who took more than 1,000 milligrams per day (mg/day) of omega-3s had an increased risk of atrial fibrillation (AFib), a common heart arrhythmia (when the heart beats irregularly or at an unhealthy speed). This research conflicts with prior research that suggests the intake of omega-3 reduces atrial fibrillation.

Speak with your healthcare provider if you have or are at risk for AFib and want to try omega-3s to discuss the correct dosage for you.

How Much Is Too Little?

Adults should consume 6 to 8 ounces of fish per week (based on a 2,000-calorie diet).If you do not eat fish, you need to get omega-3s from plants, but very little will be converted to EPA and DHA. Too little omega-3 fatty acids can result in a deficiency, although it's very rare in the United States.

Summary

Omega-3 fatty acids are essential nutrients that must be consumed from the diet or via supplementation. Omega-3s can be found in plant-based oils, flaxseed, fatty fish, and more. The optimal daily dosage depends on age, gender, and omega-3 levels. If you have difficulty eating enough omega-3s, particularly if you follow a vegan or vegetarian diet that has low DHA and EPA, ask your healthcare provider for supplement recommendations.