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Woman comforting mother who has depression and low omega-3 levels

How Omega-3 Fights Depression

Japanese scientists recently discovered that people with higher blood levels of omega-3s had a 43% lower risk of depression. Other studies show that fish oil supplements improve effectiveness of anti-depression drugs.

Scientifically reviewed by: Julia Dosik, MPH, in August 2023. Written by: Leslie Stanton.

In a brand new study, scientists in Japan have documented a strong correlation between low blood levels of omega-3 fatty acids and higher symptoms of depression.1

This study is important since depression is a growing worldwide health problem.1

Drugs to treat depression are only partially effective and produce side effects.

A growing body of consistent findings reveals a close link between depressive symptoms and chronic inflammation.2-4

What this means is that compounds like omega-3s, with proven anti-inflammatory effects, may also alleviate depression—and that’s what new studies are finding!

New Study from Japan

New Study from Japan  

A Japanese study published in 2016 evaluated the connection between blood levels of omega-3 fatty acids (EPA/DHA) and clinical depression scores.

This was a large rigorous “cross-sectional” study of 2,123 subjects (1,050 men and 1,073 women) aged 40 years or older. The researchers used a standard 20-question scale of depressive symptoms, which has previously been validated to show that scores of 16 or higher represent people with relevant depressive symptoms. Blood specimens were then drawn for analysis of various types of fatty acids.1

The first finding showed that people with the lowest levels of omega-3 fats were at the highest risk of depression, and vice versa.

What the scientists found was that those in the group with higher blood levels of omega-3s had a 43% lower risk of depression.1

In order to examine this relationship more closely, the subjects were divided into specific groups based on their blood levels of the omega-3 fats EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid).

Researchers found that subjects with the lowest level of EPA experienced more depressive symptoms. Subjects in the highest EPA range showed a 36% lower risk of depression.1

When the researchers looked at DHA levels alone, they found that those with the highest levels of DHA had a 42% lower risk for depression when compared to those with low levels of DHA.1

The implications of this latest study are profound. They strongly suggest that supplementation with fish oil rich in omega-3 fats, particularly EPA and DHA, should be considered by most people at risk for depressive illness.

And that probably means just about anyone over 40 years old should be supplementing with omega-3s, especially due to what is known about rising levels of inflammation with age and their impact not only on mental health but also on cardiovascular and metabolic health as well.5

What You Need to Know
Omega-3 Fatty Acids and Depression

Omega-3 Fatty Acids and Depression

  • Many older adults suffer from depressive symptoms and major depression.
  • It is now recognized that chronic inflammation is an important contributor to depression risk.
  • Omega-3 fats are well-known for their powerful anti-inflammatory properties.
  • A new study demonstrates close links between low omega-3 blood levels and risk for depressive symptoms, helping to further strengthen the inflammation-depression link.
  • Earlier studies have already shown that the administration of omega-3 in conjunction with antidepressant treatment is superior to antidepressant treatment alone.
  • Omega-3 supplementation should be a major part of any serious age-decelerating regimen, because of the widespread benefits of its anti-inflammatory properties.

Related Studies

There are already a number of small studies demonstrating the protective effects of fish oil/omega-3 supplementation on depression.

One study showed that, in patients with known major depressive disorder, the combination of the antidepressant drug citalopram (Celexa®) with an omega-3 supplement was superior to the drug alone in relieving depressive symptoms.6

The supplement dose was two 1 gram capsules containing a total of 900 mg EPA and 200 mg DHA taken twice daily. Total EPA/DHA intake was 2,200 mg daily, which would be considered a good daily dose of EPA/DHA by today’s standards.

Those taking the omega-3 supplement plus citalopram showed significantly greater improvement in their scores on a standard depression rating scale, beginning at four weeks after initiation of therapy, compared to those on the drug alone.6

Two studies conducted in people on hemodialysis for end-stage kidney disease (who are at high risk for depression)7 demonstrated the value of omega-3s and highlighted the connection with inflammation. One study showed that a daily omega-3 supplement totaling 360 mg EPA and 240 mg DHA, three times daily, produced significant reductions in markers of inflammation, while significantly reducing scores on a standard depression index after four months of therapy.8 The second study showed that the same omega-3 dosing produced a highly significant reduction in depression index scores, while producing a significant improvement in quality-of-life scores.9

In still another study, patients taking interferon-alpha as treatment for chronic hepatitis C infection had significantly lower episodes of depression induced by the drug when they used a daily EPA supplement, compared with those taking placebo. Depression occurred in 10% of EPA-supplemented patients compared to 30% of placebo recipients. The onset of depression was delayed significantly in those on the EPA supplement.2

As we learn more and more about the role of inflammation in producing so many age-related disorders, including cardiovascular disease, diabetes, cancer, and depression, the value of taking a daily supplement of omega-3 fatty acids becomes increasingly clear.


Depressive symptoms are widespread among older adults.

Ongoing human research has confirmed that depression has roots in chronic inflammatory processes.

A new human study has confirmed that people with higher omega-3 blood levels have significantly lower risk of depression, supporting earlier studies demonstrating both reductions in inflammatory markers and in depressive symptoms with omega-3 supplementation.

Omega-3 supplementation should be considered for anyone suffering depressive symptoms. It may take several months for beneficial effects to be realized.

If you have any questions on the scientific content of this article, please call a Life Extension® Wellness Specialist at 1-866-864-3027.


  1. Horikawa C, Otsuka R, Kato Y, et al. Cross-sectional association between serum concentrations of n-3 long-chain PUFA and depressive symptoms: results in Japanese community dwellers. Br J Nutr. 2016;115(4):672-80.
  2. Su KP, Lai HC, Yang HT, et al. Omega-3 fatty acids in the prevention of interferon-alpha-induced depression: results from a randomized, controlled trial. Biol Psychiatry. 2014;76(7):559-66.
  3. Grosso G, Pajak A, Marventano S, et al. Role of omega-3 fatty acids in the treatment of depressive disorders: A comprehensive meta-analysis of randomized clinical trials. PLoS ONE. 2014;9(5):e96905.
  4. Grosso G, Galvano F, Marventano S, et al. Omega-3 fatty acids and depression: scientific evidence and biological mechanisms. Oxid Med Cell Longev. 2014;2014:313570.
  5. Zulyniak MA, Roke K, Gerling C, et al. Fish oil regulates blood fatty acid composition and oxylipin levels in healthy humans: A comparison of young and older men. Mol Nutr Food Res. 2016;60(3):631-41.
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  7. Kimmel PL, Peterson RA. Depression in patients with end-stage renal disease treated with dialysis: has the time to treat arrived? Clin J Am Soc Nephrol. 2006 May;1(3):349-52.
  8. Gharekhani A, Khatami MR, Dashti-Khavidaki S, et al. The effect of omega-3 fatty acids on depressive symptoms and inflammatory markers in maintenance hemodialysis patients: a randomized, placebo-controlled clinical trial. Eur J Clin Pharmacol. 2014;70(6):655-65.
  9. Dashti-Khavidaki S, Gharekhani A, Khatami MR, et al. Effects of omega-3 fatty acids on depression and quality of life in maintenance hemodialysis patients. Am J Ther. 2014;21(4):275-87.