The Depression-Fighting Power of Omega-3s: What 67 Clinical Trials Revealed

Fish oil is most known for its heart health benefits (hello, lower triglycerides), but EPA and DHA omega-3-rich fish oil also has a powerful effect on mood. Studies have shown that people living in countries with higher levels of fish intake1 had lower rates of depression.

With an estimated 5% of the world’s population2 suffering from depressive feelings, there’s an urgency to find treatments that can help prevent depression, ease related symptoms, or reverse it altogether. 

More and more clinical trials are also pointing to omega-3s as a science-backed solution for mood disorders (and we’re thrilled to see fish oil receive the attention it deserves). 

Here’s what this study found (including the exact amount of daily omega-3s you should aim for).

About this latest study

A total of 67 clinical trials were included in this review and meta-analysis—meaning omega-3 intake (from foods, supplements, or a combo) or lack thereof for the duration of the study was predetermined by the researchers. 

The participants in these studies were a mix of people who were free of depression at the start or who already had mood or cognitive disorders (like depression, Alzheimer’s disease, stress, or mild cognitive impairment). 

The study was able to evaluate both the preventive and treatment effects of omega-3 fatty acids.

Results revealed fish oil is beneficial for those with depression

After all these studies were analyzed, the data clearly (and significantly) showed that fish oil consumption helped people with depressive symptoms feel better. 

More specifically, for each 1-gram increase in omega-3 fatty acid supplements, there was a large improvement in the severity of depression. 

Though researchers aren’t yet clear on the specific ways in which EPA and DHA work to target mental well-being4, they speculate it could be due to their role in promoting healthy blood flow, preserving cell membranes, and interacting with mood-related molecules in the brain. 

Does it help prevent depression?

But omega-3 intake didn’t seem to help stop people with depression from developing it. 

While past population data show that higher fish intake and levels of circulating omega-3s5 in the blood are linked to lower depression rates—indicating there’s a correlation between the two—clinical trial data do not consistently show that increasing omega-3 intake is a surefire way to ward off depression6. 

So, how much fish oil do you need to see a benefit?  

Any less, you may not see a benefit (or as much as a benefit). And taking in more didn’t yield significantly better results in this case. 

How to increase your omega-3 intake

One way to up your omega-3 intake is to eat more fatty fish. The American Heart Association8 recommends eating one to two servings of oily fish (like salmon, mackerel, herring, and anchovies) a week as a minimum.

For a more potent—and consistent way—to boost your omega-3 intake, it’s a good idea to lean into a high-quality supplement (here are our favorites). Most fish oil supplements provide that desired dose of 1 to 1.5 grams of omega-3s. 

If you wanted to try to get that amount from food alone, you would end up eating one (whole) fish a day9. 

The takeaway

Omega-3s clearly play a role in mental health. More and more research is showing that higher amounts of daily EPA and DHA are beneficial for people with depression and other mood disorders. 

Getting the therapeutic amount of omega-3s (considered to be between 1 and 1.5 grams daily) for cognitive and heart health benefits is really hard to do through the diet alone, so incorporating a quality supplement is likely the best route to take.