A dietitian reveals 7 unexpected advantages of omega-3s

If you rarely eat fish or skip a fish oil supplement, you might be missing out on an essential nutrient: omega-3 fatty acids. These fats, abundant in fatty fish like salmon, are widely recognized for reducing inflammation, but their advantages extend far beyond that. Omega-3s influence mood, memory, joint health, and more.

Despite their importance, intake remains low. A 2020 review found that the average U.S. adult consumes only about half the recommended amount of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the two most active omega-3 forms.

Drawing on insights from registered dietitians Jennifer Pallian and Anne Murray, as well as my own experience, here are some lesser-known ways omega-3s support overall wellness.

1. Relieving Joint Discomfort

Joint stiffness or soreness at the end of the day may improve with higher omega-3 intake. These fats may reduce inflammation, protect cartilage, aid tissue repair, and lower inflammatory markers like interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-).

2. Promoting Heart and Vascular Health

Omega-3s support cardiovascular health by reducing inflammation, improving blood flow, and increasing HDL ("good cholesterol"). They may also lower triglycerides and decrease the risk of heart disease. A 2025 analysis of 29 studies showed that higher omega-3 blood levels are associated with a reduced risk of total and ischemic stroke.

3. Supporting Eye Health

These fatty acids are crucial for vision and eye function. Omega-3s can stabilize tear production, reduce surface damage, and potentially lower the risk of age-related macular degeneration (AMD). Higher DHA and EPA intake is linked to a 3239% lower risk of late-stage AMD.

4. Helping Maintain Blood Sugar Balance

Omega-3s may improve insulin sensitivity and help regulate blood glucose levels by reducing inflammation, which aids glucose uptake in cells. A review of 30 studies found that nearly 70% reported positive effects on blood sugar or insulin resistance, though benefits were generally modest.

5. Supporting Weight Management

While not a weight-loss cure, omega-3s may reduce belly fat, improve insulin sensitivity, lower inflammation, and influence hormones like leptin and adiponectin that regulate appetite and fat storage.

6. Boosting Immunity

Omega-3s help the immune system by enhancing cell communication and the bodys natural response to infections. Research is ongoing into their potential role in preventing infections, including COVID-19.

7. Essential for Brain Function

DHA is a critical structural component of neurons and cell membranes, supporting signaling and cognitive performance. Omega-3s may enhance memory, learning, focus, and possibly mental health, though results for depression, anxiety, ADHD, and bipolar disorder remain mixed.

Recommended Omega-3 Intake

No official RDA exists, but 250500 mg/day of combined DHA and EPA or two servings of fatty fish per week is generally recommended for healthy adults. Higher doses may be advised for heart disease or high blood pressure under medical supervision.

Signs of Deficiency

Low omega-3 levels may manifest as dry, scaly skin, chronic fatigue, irritability, joint pain, cold extremities, dry eyes, or hair thinning. Blood tests measuring EPA and DHA are the most accurate indicators.

Safety and Supplementation

Excessive omega-3 intake is rare through diet but can occur via supplements. The FDA suggests keeping total EPA and DHA supplements under 5 grams/day to avoid bleeding risks, immune suppression, or digestive issues.

Top Food Sources of Omega-3

• Salmon: 1,240 mg DHA, 590 mg EPA per 3 oz
• Herring: 940 mg DHA, 770 mg EPA per 3 oz
• Sardines: 740 mg DHA, 450 mg EPA per 3 oz
• Mackerel: 590 mg DHA, 430 mg EPA per 3 oz
• Rainbow trout: 440 mg DHA, 400 mg EPA per 3 oz

Plant sources like flaxseed, chia seeds, and walnuts contain ALA, which the body converts inefficiently into EPA and DHA.

Considerations for Supplements

Side effects may include fishy aftertaste, gastrointestinal issues, or minor skin reactions. Vegan options like algae-based DHA and EPA supplements provide an effective alternative to fish-derived products.

Summary

Omega-3 fatty acids are vital for joint, heart, brain, eye, and immune health. While food is the best source, supplements can help meet requirements when needed. Proper dosage and monitoring with a healthcare professional ensure safety and effectiveness.

Experts Consulted

Jennifer Pallian, RD, Food Scientist and Founder of Foodess
Anne Murray, MS, RDN, Founder of Nourished by Anne

Author's Analysis: Why Omega-3 Intake Remains a Public Health Concern

Despite widespread awareness of their benefits, omega-3 fatty acids continue to be underconsumed in the United States. Research shows that the average adult receives only about half of the recommended EPA and DHA levels, highlighting a clear gap between nutritional guidelines and everyday diets.

The evidence is compelling: omega-3s support joint comfort, cardiovascular health, eye function, blood sugar regulation, and brain performance. Clinical studies and meta-analyses confirm that higher intake correlates with reduced inflammation, improved lipid profiles, and lower risk of age-related conditions such as macular degeneration and stroke.

Food sources remain the most effective way to achieve adequate omega-3 levels, with fatty fish like salmon, herring, sardines, and mackerel providing the highest EPA and DHA content. For those unable to consume sufficient fish, algae-based or standard supplements can fill the gap safely when dosed appropriately.

In summary, omega-3 fatty acids are not merely supportive nutrients but essential for multiple systems in the body. Consistent intake, whether through diet or supplementation, is crucial for long-term health maintenance, and public health strategies should focus on bridging this nutritional shortfall.

Sources:

• 7 surprising benefits of omega-3s, according to a dietitian