Fish oil contains omega-3 fatty acids that may help manage symptoms of mental health conditions such as bipolar disorder.

Bipolar disorder has several possible causes. One is the way your immune system may cause brain inflammation.

Researchers believe that fish oil activates anti-inflammatory mechanisms. This can lead to improvements in both physical and mental health.

Including fish in your diet several times per week is one way to get valuable omega-3 fatty acids. Another way is to try a fish oil supplement containing DHA and EPA.

Bipolar disorder is a complex mental health condition that features extreme changes in mood. According to the National Institute of Mental Health (NIMH), bipolar disorder affects around 4.4% of US adults.

The mood shifts of bipolar disorder aren’t your fault or something you can “try harder” to change. There are genetic, biological, and environmental factors that impact the way your brain regulates mood.

But there’s a range of effective treatments for bipolar disorder. The combined approach of medication and therapy is often successful.

Including omega-3 supplements as part of your treatment might also help. If you want to try fish oil, it’s recommended that you discuss it with your doctor first.

There’s evidence that suggests the omega-3 fatty acids found in fish oil may help with mood disorders and other mental health conditions.

  • A 2015 study found that fish consumption might help prevent depression.
  • A 2017 study examined the link between inflammation and major depressive disorder (MDD) and bipolar disorder. Researchers found that omega-3 fatty acids may work alone (monotherapy) or with other treatments (adjunct therapy) to help people living with MDD and bipolar disorder.
  • A 2015 case study of a young girl with bipolar disorder found that 2 years of omega-3 supplementation resulted in significant and sustained improvement in manic, psychosis, and depressive symptoms.
  • A 2020 trial found that DHA supplementation resulted in improved cognitive performance in emotion inhibition — having difficulty expressing spontaneous emotion — in people with bipolar disorder.

Results are mixed, though. A 2020 study with adolescents found that fish oil wasn’t any better than a placebo for easing depressive symptoms. But it was safe, well-tolerated, and rated higher by mental health professionals for improving global symptoms.

Omega-3 fatty acids like docosahexaenoic (DHA) and eicosapentaenoic acids (EPA) originate in phytoplankton. The fish that feed on phytoplankton provide dietary or supplemental sources of these fatty acids.

DHA and EPA affect the brain in several different ways. They’re involved in functions related to:

  • neuroinflammation
  • neurotransmission
  • neurogenesis

There’s evidence that omega-3 fatty acids may help regulate the neuroinflammation that can contribute to bipolar disorder.

A 2016 review of 17 clinical studies found low levels of omega-3 fatty acids in symptomatic bipolar disorder. The review also found that omega-3 fatty acid supplementation was successful in treating depression or mania in five out of five trials.

Omega-3 fatty acids may also play a part in neurotransmission receptor function. A 2015 study involving rats found that fish oil supplements impacted hippocampal receptors and had an antidepressant-like effect.

Omega-3 fatty acids also help new neurons form by changing cell membrane fluidity so that serotonin can work more effectively. Serotonin is a neurotransmitter that can stimulate the growth of new neurons.

Omega-3 fatty acids play an important role in the development, functioning, and even aging of the human brain. A deficiency increases the chance of various mental health conditions such as:

Insufficient omega-3 fatty acids can also contribute to neurodevelopmental differences such as attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD).

The best source of omega-3 fatty acids is fish. Unlike a fish oil supplement, fish contains other beneficial ingredients such as protein and vitamins.

You can still benefit from a fish oil supplement though if it has both DHA and EPA.

It’s OK to take fish oil at any time of the day since the effects aren’t immediate. It can take weeks before you notice the benefits of fish oil supplementation.

If you take fish oil with a meal containing fat, this can increase the effectiveness and bioavailability of the omega-3 fatty acids.

Fish oil may slow blood clotting. Consider consulting with a healthcare or mental health professional before taking fish oil supplements if you take anticoagulant medication, or if you have an upcoming surgery.

People with seafood allergies may not be able to take fish oil supplements.

There’s conflicting information about long-chain omega-3s and prostate cancer. Research shows an elevated chance with higher omega-3 blood levels, but a reduced chance with frequent dietary consumption of seafood, and no link with dietary omega-3 intake.

Fish oil may have side effects, although they’re usually mild. These can include:

  • diarrhea
  • heartburn
  • headache
  • nausea
  • unpleasant taste
  • bad breath
  • unpleasant odor in sweat

It’s also possible that fish oil may worsen acne for some people.

Fish oil contains omega-3 fatty acids, which can help your brain in several ways. Low levels of omega-3 fatty acids are associated with certain mental health conditions.

Fish oil can decrease inflammation, which researchers believe may be a key part of bipolar disorder.

Adding fish to your diet is one way to increase your omega-3 fatty acid intake. A fish oil supplement is another option, but it’s important to discuss this with your doctor first, particularly if you take anticoagulant medication.

Psych Central has a bipolar disorder resource hub you can visit for more information about managing bipolar disorder.