What Happens to Your Mood When You Take Omega-3s Regularly

Although omega-3s—essential polyunsaturated fats that the body cannot produce itself—are best known for their cardiovascular and cognitive benefits, they are also widely marketed as mood-enhancing supplements. But to what extent does this statement hold water? Here’s what you need to know about omega-3s and mental health.

Some research suggests that omega-3s can improve mood, but only in certain circumstances, experts point out.

For example, there is little strong support for the idea that omega-3s can improve mental health problems such as anxiety, manic symptoms, mild depression, or generalized stress, said Aleta Storch, MS, RDN, LMHC, a registered dietitian and therapist based in Bellingham, Washington. However, when it comes to major depressive disorder, there is stronger evidence that omega-3 supplements may provide relief.

A 2023 observational study, for example, found that people with mild or moderate depression who combined omega-3s with three different types of SSRI medications for two years experienced a significant decrease in their depressive symptoms. A 2021 review of 35 studies concluded that, compared to a placebo, omega-3s may provide small to modest benefits against depression.

Evidence suggests that eicosapentaenoic acid (EPA), the type of omega-3 naturally found in seafood, may provide more benefits than docosahexaenoic acid (DHA), 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. “We should therefore avoid big promises,” he said.

Omega-3s affect the brain in several ways, which could explain their potential to relieve depressive symptoms. One is their ability to reduce 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 neuron growth, said Lina Begdache, PhD, RDN, CDN, CNS-S, FAND, associate professor of health and wellness studies at Binghamton University in New York.

Omega-3s can even affect brain structure. “They increase the actual flexibility of neuron membranes,” Storch said, allowing mood-regulating chemicals to move more easily throughout the brain.

If you’re just feeling a little down, it may not be worth adding omega-3 to your supplement routine. “At this point, the evidence really does not support the use of omega-3s as a treatment option for people with occasional or mild depressive symptoms or anxiety,” Storch said.

This may not be the case, however, for people with more severe depression, especially those who consume little or no omega-3-rich foods, such as fatty fish, nuts, flaxseeds and certain vegetable oils, Bass said.

However, experts have warned that omega-3s should not be considered the only treatment for depression. “The benefits are generally moderate, gradual, and most effective when combined with established therapies,” Begdache said.

Before starting any supplement, experts recommend consulting a doctor to find out if it’s right for you. Although omega-3s are generally safe, Bass said, higher doses can increase bleeding time and pose risks for people taking blood thinners or antiplatelet medications.