What Happens to Your Body When You Take Omega-3s Every Day

Most people don't come close to getting the omega-3s they need to stay healthy. Could a supplement help?
By Karen Ansel, M.S., RDN
Published on March 19, 2023

Fat isn't something many people are trying to eat more of. But there is one kind of fat that almost everyone needs to eat more often, namely omega-3 fats. Best known for heart and brain health, omega-3s do lots of great things for your body, like keeping your immune system strong and supporting visual, hormonal and reproductive health.

Yet, most people fall way short. According to the National Institutes of Health, on average, adults consume only 90 to 110 of the daily 250 milligrams of omega-3s that have been shown to protect against death from heart disease. Of course, you could easily get this from a couple of servings of fatty fish each week. But for most, that's nothappening, per the USDA's Economic Research Service. Why? "Most people avoid seafood because they don't like the taste, texture or smell," says Valerie Agyeman, RD, a nutritionist and host of the Flourish Heights Podcast. Others don't know how to prepare it.

If you're not a fish eater, or you could just use a little bump, here's how to decide if an omega-3 supplement is right for you.

What Are Omega-3 Fatty Acids?

Omega-3s are a small—yet powerful—family of polyunsaturated fats. They're found in plants, mainly in the form of alpha-linolenic acid (ALA), and in seafood as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). People usually get plenty of ALA from plant foods like walnuts, chia seeds, soybeans, flaxseed and soybean oil. DHA and EPA are harder to come by because they're only found in fish, shellfish and marine algae.

Omega-3 Supplements

Omega-3 supplements typically supply EPA and DHA from:

Fish oil from anchovies or sardines. But they may also be made from other fatty fish like salmon, tuna or pollock.
Krill oil comes from tiny crustaceans called krill. It also contains astaxanthin, an antioxidant that may support eye health, per a 2020 article published in Marine Drugs.
Cod liver oil, as the name implies, is obtained from cod fish liver.
Algae oil is derived from marine microalgae, making it the only vegan DHA and EPA source.

What Happens When You Take Omega-3s Every Day

Found in every cell in your body, omega-3s work hard to keep you healthy, per the NIH. Here are some of the main health benefits of omega-3s.

May Reduce Your Heart Attack Risk

In addition to lowering blood pressure and triglycerides, omega-3s may also prevent blood clots that can lead to heart attacks. They are so helpful that a 2021 Mayo Clinic Proceedings meta-analysis of 40 clinical trials found that people who took DHA/EPA supplements were 13% less likely to have a heart attack, and those who did were 35% less likely to die.

May Improve Your Brain Function

Your brain is roughly 60% fat, and 10% to 20% of that fat is DHA, per a 2016 article in Nutrients. There, it fortifies the delicate membranes that protect your brain cells, making it critical for short- and long-term cognitive health. "Observational studies suggest that people whose diets are higher in omega-3 fats have a lower risk of cognitive decline," says Monica Reinagel, M.S., LDN, CNS, a licensed nutritionist and host of the Nutrition Diva Podcast. "And there's limited data to suggest that omega-3 supplementation might also have some beneficial effects."

May Protect You Against Depression

Studies on omega-3s' ability to fight depression are encouraging but somewhat inconsistent. However, some research, such as a 2019 review in Translational Psychiatry, has found that a dosage of up to 1 gram of omega-3s per day can improve depression symptoms. However, more research is needed to understand how omega-3s can help manage depression.

Could Support Your Vision

There's good news if you are one of the 14% of people with dry eyes. According to a 2019 meta-analysis published in Nutrients, research reveals that DHA may tame the inflammation that causes dryness and boost tear production for better lubrication. "There's also limited research that omega-3 supplementation may slow the progression of age-related macular degeneration," says Agyeman. "But more research is needed."

Promote a Healthy Pregnancy

"EPA and DHA from fish are critical for a mother's brain and heart health," says Agyeman. "They also support a baby's normal brain development, which rapidly accelerates during the last trimester." According to a 2018 Cochrane Library review of 70 studies, consuming omega-3s from food or supplements may reduce a woman's risk of preterm labor and delivering a low-birthweight baby.

What to Look for in an Omega-3 Supplement

Dosage

As of March 2023, the United States doesn't have an official omega-3 recommendation. According to the Food and Drug Administration, taking up to 5,000 mg daily is safe.

Form

Soft gels are the most popular form of omega-3 supplement. They come in different sizes, so if you aren't a fan of large pills, you can take several small ones instead. To prevent "fish burps," look for enteric-coated capsules. "If swallowing pills isn't your thing, try fish oil liquids or emulsions," says Elana Natker, RD, director of consumer and health practitioner communications at the Global Organization for EPA & DHA Omega-3s. "Many emulsions are flavored to mask the fish taste, and there are also gummies or soft chews that have a pleasant flavor."

Concentration

Since EPA and DHA have slightly different benefits, look for a supplement that contains both. The average omega-3 supplement contains roughly 120 mg of DHA and 180 mg of EPA, although this varies from brand to brand.

Purity

Fish oil supplements contain lower levels of mercury, PCBs, dioxins and other environmental contaminants than fresh fish, says Natker. "Plus, manufacturers purify the oil to reduce the level of environmental contaminants," she says. If you want extra assurance, look for products with third-party certification tested for contaminants.

Freshness

In addition to checking the "best by" date on the package, follow your nose. "Fish oil supplements will naturally smell a bit like fish," says Natker. "But if it has a bad odor or smells rancid, you should probably toss it."

Frequently Asked Questions

1. When do you need to take omega-3s?

Any time works, but taking your supplement with a fat-containing meal helps boost omega-3 absorption even more, says Natker.

2. How much omega-3s do you need?

Even though the United States doesn't have an omega-3 recommendation, the European Food Safety Authority recommends consuming 250 mg of EPA plus DHA daily (350 to 450 mg if you are pregnant or nursing).

3. How do you know if you need to take omega-3s?

You may not need a supplement if you eat two weekly servings of fatty fish. However, if you have heart disease, are pregnant or are vegan, talk to your doctor.

4. Who should avoid taking omega-3s?

"Omega-3 fatty acids reduce the tendency of blood to form clots, and in some cases, this is desirable," says Reinagel. "But for someone at risk of excessive bleeding, it might be harmful." Speak to your doctor if you take blood thinners or plan to have surgery or a dental procedure.

The Bottom Line

An omega-3 supplement may make sense if you don't eat a couple of servings of fish per week, but it won't provide other nutrients in fish like lean protein, potassium, B vitamins and selenium. So think fish first, supplements second.

https://www.eatingwell.com/article/8035578/omega-3-supplements-benefits/