7 surprising benefits of omega-3s, according to a dietitian
If you’re not eating fish at least twice a week — or taking a fish oil supplement — you might be missing out on a powerful nutrient: omega-3 fatty acids. Found mostly in fatty fish like salmon, omega-3s are best known for their anti-inflammatory effects. But that’s only part of the story. These essential fats influence everything from your mood and memory to joint pain.
Still, despite their importance, many people don’t get enough. A 2020 review estimated that the average intake of eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) — the two most active forms of omega-3 — in U.S. adults is only about half what many experts recommend.
I consulted two of my fellow registered dietitians and drew on my own experience as a nutrition writer to explore some lesser-known benefits of omega-3 fatty acids. From boosting brain power to supporting skin health, read on for surprising ways these fats may support your well-being — and how to make sure you’re getting enough.
1. They may ease joint pain
Joints feeling sore or creaky by the end of the day? Boosting your omega-3 intake might help. According to Vancouver-based dietitian Jennifer Pallian, these healthy fats may help reduce inflammation, ease pain and improve joint mobility in adults with osteoarthritis. They work at the cellular level — protecting cartilage, supporting tissue repair and lowering inflammatory markers like interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α).
2. They support heart and overall vascular health
One of the best-supported benefits of omega-3s is their positive impact on vascular health, including the risk of cardiovascular disease. “Omega-3s support heart health by decreasing inflammation, potentially raising ‘good cholesterol’ [aka HDL] and improving blood flow,” explains Austin-based dietitian Anne Murray.
Research also suggests that omega-3s may help lower high triglyceride levels and reduce the risk of dying from heart disease. They may even offer some protection against stroke. A 2025 analysis of 29 studies found that people with higher blood levels of omega-3s had a significantly lower risk of both total and ischemic stroke, though no link was found with hemorrhagic stroke.
3. They may support eye health and vision
Omega-3s are essential for eye health and development. According to Pallian, these healthy fats may ease symptoms of dry eye disease (DED) by stabilizing the tear film, increasing tear production and reducing surface damage. A 2023 review supports this, finding that high-dose, long-term omega-3 supplementation was effective in reducing dry eye symptoms in otherwise healthy adults.
Pallain also notes that omega-3s may lower the risk of age-related macular degeneration (AMD) — a leading cause of vision loss that affects more than 12% of U.S. adults aged 40 and older. One meta-analysis found that people who consumed the highest amounts of DHA and EPA had a significantly lower risk of developing late-stage AMD — 39% and 32% lower, respectively — compared to those with the lowest intake. While more research is needed, this protective effect is thought to stem from omega-3s’ ability to decrease inflammation, inhibit the growth of abnormal blood vessels and help preserve the health of your retinal cells.
4. They might help keep blood sugar levels steady
Some research suggests that omega-3s could help keep your blood sugar levels in check and improve your body’s ability to use insulin — the hormone responsible for shuttling glucose (aka sugar) from your bloodstream into your cells. According to Pallain, it’s thought that by reducing inflammation, omega-3s make it easier for your cells to take in glucose, which in turn helps lower blood sugar levels.
One large review of 30 studies found that nearly 70% reported at least one favorable metabolic outcome (e.g., lower fasting sugar or improved insulin resistance) with omega-3 supplementation in adults with or at risk for type 2 diabetes. However, many of those benefits were modest, so it’s best to take these results with a grain of salt.
5. They may support weight management
Omega-3s aren’t a magic bullet for weight loss. However, they might help give your metabolism a nudge in the right direction. Some research suggests that omega-3s may help reduce belly fat, improve insulin sensitivity and decrease chronic inflammation — all of which play a role in weight management. These healthy fats may also influence hormones like leptin and adiponectin, which help regulate appetite and fat storage.
6. They may help boost immunity
Omega-3s may give your immune system an added edge, helping your body respond to illness and infection more effectively. “Omega-3s can benefit immune function by improving inflammation and cell communication and supporting the body’s natural process in fighting infections,” says Murray.
Although research is still ongoing and more studies are needed, omega-3 fatty acids are also being explored for their potential to help prevent infections, like COVID-19.
7. They’re essential for brain health
From staying focused at work to maintaining a sharp memory, omega-3s play a key role in helping your brain function at its best. DHA, in particular, is essential — it’s a structural component of neurons and cell membranes, supporting cell signaling and membrane fluidity. Research suggests that increasing your omega-3 intake may boost blood flow to the brain, which can enhance memory, learning and overall cognitive performance.
There may also be mental health benefits. Some older studies suggest omega-3s could help reduce symptoms of depression and anxiety, especially when used alongside treatments like therapy or antidepressants. However, findings have been mixed. These fatty acids are also being explored for their potential in managing ADHD in kids and bipolar disorder, though current evidence remains inconclusive.
How much omega-3 do you need?
There’s no official recommended dietary allowance (RDA) for omega-3s. However, most experts agree that 250-500 milligrams (mg) per day of combined DHA and EPA — or at least two servings of fatty fish per week — is a good target for healthy adults.
People with certain health conditions may benefit from higher doses. For example, the American Heart Association recommends 1,000 mg of combined DHA and EPA daily for individuals with heart disease and up to 3,000 mg per day for those with high blood pressure. Since needs can vary, the best way to determine how much omega-3 to get through diet or supplements is to consult with your doctor, registered dietitian or another health care professional.
Signs of omega-3 deficiency
Wondering if you’re getting enough omega-3s in your diet? While there’s no gold standard for diagnosing omega-3 deficiency, low blood levels — measured via plasma, serum or red blood cells — can indicate inadequate intake.
If you’re not ready to get your blood drawn, the first signs to look out for are changes in your skin. Rough, scaly patches, increased breakouts and dermatitis can all signal low omega-3 intake. Other potential signs include:
- Chronic fatigue
- Increased irritability or anxiety
- Joint pain
- Heart problems
- Cold hands and feet
- Dry eyes or blurred vision
- Thinning hair or increased shedding
Keep in mind that these symptoms are not exclusive to omega-3 deficiency and may be signs of other health conditions or nutritional deficiencies. If you have concerns, be sure to talk to your health care provider for guidance.
Can you consume too much omega-3 from supplements?
“Just like any other nutrient, food or supplement, it’s possible to consume too much, but this mostly happens from over-supplementation, not dietary consumption,” says Murray.
While there’s no established Tolerable Upper Limit (aka the maximum amount you can take without serious side effects), the Food and Drug Administration recommends keeping combined EPA and DHA supplements below 5 grams per day. That’s because high doses can increase the risk of bleeding, suppress immune function and cause digestive issues like nausea and diarrhea.
The good news? It’s pretty hard to overdo it with food alone. Fatty fish like sardines, mackerel and salmon deliver a solid dose of omega-3s to help you meet your needs without tipping the balance. “Aim to get your omega-3s through food sources first,” says Murray. “Then you can test your levels and work with a practitioner to find the right dosage and supplement if needed.”
FAQs
Which foods are high in omega-3s?
Fatty fish are among the best sources of omega-3s because they’re rich in EPA and DHA. Here’s how much EPA and DHA you’ll find in a 3-ounce serving of different fish:
- Salmon: 1,240 mg DHA, 590 mg EPA
- Herring: 940 mg DHA, 770 mg EPA
- Canned sardines: 740 mg DHA, 450 mg EPA
- Mackerel: 590 mg DHA, 430 mg EPA
- Rainbow trout: 440 mg DHA, 400 mg EPA
Plant-based foods like flaxseed oil, chia seeds and walnuts also contain omega-3 fatty acids, but in the form of alpha-linolenic acid (ALA). Because ALA needs to be converted into EPA and DHA — the more active forms — it’s unclear how much ALA is required to deliver the same health benefits.
Is there a downside to taking omega-3 supplements?
Although omega-3s are generally safe and well-tolerated, they’re still not entirely risk-free. “Mild and commonly reported side effects include a fishy aftertaste, belching, indigestion, diarrhea, nausea, abdominal discomfort, constipation, rash and joint pain,” says Pallian. She notes that other potential negative side effects may occur with certain formulations, including changes in taste or liver problems. “Always consult with your health care provider before taking any supplements,” she says.
Are omega-3s helpful for weight loss?
While more research is needed, omega-3s may aid weight loss efforts by reducing chronic inflammation, improving insulin sensitivity and altering hunger hormone levels. Plus, foods high in omega-3s, like fish, tend to be more filling thanks to their combination of protein and fat, which digest more slowly and may help keep you from reaching for a snack just an hour or two after eating.
Are there vegan sources of omega-3 DHA and EPA?
Yes. In fact, the reason fish are a great source of DHA and EPA is that they eat certain types of marine algae that are naturally rich in these essential fats. The most effective way to obtain vegan DHA and EPA is by taking an algae-based omega-3 supplement. (Looking for a supplement? Future Kind Vegan Omega-3 won over Yahoo nutrition editor and registered dietitian Kelli McGrane.)
What’s the difference between DHA, EPA and ALA?
“DHA, EPA and ALA are all essential fatty acids, meaning our bodies need to obtain them through food for proper functioning,” explains Murray. While they’re all in the same family, the key difference lies in how the body processes them.
ALA, primarily found in plant sources, like flaxseeds, chia seeds and walnuts, needs to be converted into EPA or DHA to be effectively used by the body. “However, this conversion process is inefficient — much of the ALA is burned for energy, and only a small amount becomes usable EPA or DHA,” says Murray. For this reason, getting EPA and DHA directly from foods like fatty fish or from supplements is often a more reliable way to meet your omega-3 needs.
What happens if I take omega-3 fish oil every day?
Omega-3 supplements, including vegan and fish oil products, are generally considered safe for daily use. However, it’s essential to take only the recommended amount, as excessive intake can increase the risk of bleeding.
Meet our experts
- Jennifer Pallian, RD, food scientist and founder of Foodess
- Anne Murray, MS, RDN, founder of Nourished by Anne
Our health content is for informational purposes only and is not intended as professional medical advice. Consult a medical professional on questions about your health.
