Although omega-3s—essential polyunsaturated fats the body can’t produce on its own—are best known for their cardiovascular and cognitive benefits, they’re also widely marketed as mood-boosting supplements. But how well does that claim hold up? Here’s what to know about omega-3s and mental health.
Some research suggests that omega-3s may improve mood—but only in certain circumstances, experts stressed.
There is little robust support, for example, for the idea that omega-3s can improve mental health concerns like anxiety, manic symptoms, low-grade depression, or generalized stress, said Aleta Storch, MS, RDN, LMHC, a dietitian and therapist based in Bellingham, WA. However, when it comes to major depressive disorder, there’s stronger evidence that omega-3 supplements may offer relief.
A 2023 observational study, for instance, found that people with mild or moderate depression who combined omega-3s with three different types of SSRI medications over two years experienced a significant decline in depressive symptoms. A 2021 review of 35 studies concluded that, compared with a placebo, omega-3s may offer small-to-modest benefits for depression.
Evidence suggests that eicosapentaenoic acid (EPA), the type of omega-3 naturally found in seafood, may offer more benefits than docosahexaenoic acid (DHA), which is found in plants, according to Pat F. Bass III, MD, MS, MPH, a Louisiana-based primary care physician. He pointed to a 2019 meta-analysis that found the greatest improvement when people with depression took supplements formulated with 60% or more EPA.
Still, the overall certainty of the evidence is low, Bass noted. “So we should avoid big promises,” he said.
Omega-3s affect the brain in several ways that could help explain their potential to lift depressive symptoms. One is their ability to lower inflammation in the brain (and throughout the body), since higher levels of inflammation have been linked to depression, Storch explained.
These fats may also help regulate feel-good chemicals like serotonin, dopamine, and norepinephrine, and influence the activity of brain-derived neurotrophic factor, a protein that promotes the growth of neurons, said Lina Begdache, PhD, RDN, CDN, CNS-S, FAND, an associate professor of health and wellness studies at Binghamton University in New York.
Omega-3s can even affect the brain’s structure. “They increase the actual flexibility of the membranes within neurons,” Storch said, allowing mood-regulating chemicals to move more easily throughout the brain.
If you’re simply feeling a little low, it may not be worth adding omega-3s to your supplement routine. “At this point, the evidence really doesn’t support the use of omega-3s as a treatment option for people with occasional or mild depressive symptoms, or anxiety,” Storch said.
That may not be the case, however, for people with more severe depression—particularly those who eat little to no omega-3 rich foods, like fatty fish, walnuts, flaxseeds, and certain plant oils, Bass said.
However, experts cautioned that omega-3s shouldn’t be relied on as a sole treatment for depression. “Benefits are typically moderate, incremental, and most effective when combined with established therapies,” Begdache said.
Before starting a supplement, experts recommend consulting a doctor to discuss whether it’s right for you. While omega-3s are generally safe, Bass said, higher doses may increase bleeding time and pose risks for people on blood thinners or antiplatelet medications.
