Bipolar Disorder and Diet Part I: Omega-3 Fatty Acids

(bi)polar bears

True (type I) Bipolar Disorder (which used to be called manic-depression) affects about 1% of the population, but milder forms exist that affect an additional 5% of Americans. These include Bipolar Disorder type II, as well as more subtle bipolar spectrum mood disorders. These are very serious conditions that can cause significant distress and impairment for individuals and their families. People are often told that bipolar disorders are the result of a “chemical imbalance” that must be corrected with medications . . . but what causes this chemical imbalance?

The truth is we do not know. What we do know is that the tendency to develop bipolar disorder (and its moody cousins along the bipolar spectrum) is partly genetic and partly environmental (lifestyle). We can’t do anything right now about the genetic vulnerability, but if we understood which lifestyle factors increased our risk for these mood disorders, we could potentially reduce the incidence and/or the severity of these conditions.

Mood stabilizing medications are incredibly important tools in the treatment of bipolar disorders, but they are imperfect tools—they do not work for everyone, and come with risk of side effects. What if there were dietary changes that could reduce the need for medication in some people? After all, the chemicals in our brains come from food, so it stands to reason that what we eat could have a powerful impact on our brain chemistry, and therefore influence our mood and behavior.

Omega 3 fatty acid supplements improve bipolar depression

Omega-3 fatty acids (ALA, EPA, and DHA) and the omega-6 fatty acid LA are considered essential because they are critical components of all cells, and they are the only fats our bodies can’t make from scratch. Put simply, omega-6s promote inflammation and omega-3s reduce inflammation. We need both omega-3 and omega-6 in our diets, but we need them to be in proper balance. For example, if we get an infection, we need both forces available—first, inflammatory forces to fight off the invading bacteria, then anti-inflammatory forces to clean up the scene and begin the process of healing. The delicate balance between these two forces is vital to the health of our immune system.

Unfortunately, the typical “Western” diet is seriously lopsided, and the shift in our diets from animal-based fats to plant-based fats is the biggest reason why we are off-kilter. The two most important omega-3 fatty acids, EPA and DHA, do not exist in plant foods, and modern animal foods contain less of them than they used to due to the way they are produced. In addition, we have been told for decades that plant fats are healthier for us than animal fats, so there has been a huge increase in the amount of vegetable oil in our diets, and these are very high in omega-6 fatty acids.

Scientists estimate that our hunter-gatherer ancestors ate a diet that contained roughly equal amounts of omega-3 and omega-6 fatty acids, but that most of us civilized folk currently take in at least 15 times more omega-6 than omega-3. This imbalance is unhealthy, especially for the brain, which requires high concentrations of omega-3s:

  • Omega-3s give brain cell membranes the flexibility they need in order to function properly. Brain cells communicate with each other by exchanging chemical neurotransmitters (such as serotonin and dopamine), and in order to do this, their membranes need to be soft and pliable.
  • Omega-3s reduce the activity of brain cell signaling chemicals, such as protein kinase C (manic symptoms have been associated with hyperactivity of this compound).
  • Omega-3s provide anti-inflammatory protection to brain cells. Mood disorders are strongly associated with inflammation in the brain (on a microscopic level).

There have been lots of studies of omega-3 fatty acids in mood disorders. A recent review of the best available clinical studies found that adding daily omega-3 fatty acid supplements to mood stabilizing medications for 12 to 16 weeks significantly improved symptoms of depression in people with bipolar disorder (evidence for improvement in manic symptoms was insufficient). Among the omega-3s, EPA was found to be superior to DHA, and ALA (flax oil) was ineffective. Therefore, the current science supports the use of 1000 mg per day of an omega-3 supplement that is as high in EPA as possible.

You can also improve your omega-3/omega-6 balance by:

  1. Minimizing your use of vegetable oils, which are all high in omega-6. Those that are especially high include: safflower, grapeseed, sunflower, cottonseed, corn, walnut, and soybean oils. Choices that are lower in omega-6 include coconut oil, olive oil, cocoa butter, and palm oil.
  2. Increasing your use of healthy animal fats, which contain omega-3s and are lower in omega-6. The best sources are wild fish and naturally-raised animals (grass or pasture-fed), if available and affordable. However, even most commercially-produced animal meats contain much less omega-6 than vegetable oils do.

For more information about omega-3 and omega-6 fatty acids and the foods that contain them, please see the Fats page.

Word to the wise: studies of omega-3 supplements in bipolar disorder were conducted in people who were also taking mood stabilizing medications. We do not know if simply taking omega-3 fatty acids without medications would be helpful enough, or would work quickly enough, especially in severe cases of bipolar depression, therefore this would not be a smart strategy in an emergency.

Learn more

To learn more about diet and bipolar disorder, I recommend my post: "Bipolar Disorder and Diet Part II: Low Carbohydrate Diets." You can also test your knowledge about Omega-3s by taking my fun quizzes: "What's Your Omega-3 IQ? A Fun Quiz for a Healthier Brain!" and "Put Your Omega-3 Supplement to the Test."


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Deckelbaum RJ, Torrejons C. The omega-3 fatty acid nutritional landscape: health benefits and sources. J Nutr. 2012;142:587S-591S.

Hegarty BD, Parker GB. Marine omega-3 fatty acids and mood disorders–linking the sea and the soul. Food for Thought I. Acta Psychiatr Scand. 2011;124(1):42-51.

Kouba M, Mourot J. A review of nutritional effects on fat composition of animal products with special emphasis on n-3 polyunsaturated fatty acids. Biochimie 2011;93:13-17.

Kris-Etherton PM et al. Polyunsaturated fatty acids in the food chain in the United States. Am J Clin Nutr 2000;71(suppl):179S-188S.

Layé, S. Polyunsaturated fatty acids, neuroinflammation and well being. Prostaglandins Leukot Essent Fatty Acids. 2010;82:295-303.

Martins JG. EPA but not DHA appears to be responsible for the efficacy of omega-3 long chain polyunsaturated fatty acid supplementation in depression: evidence from a meta-analysis of randomized controlled trials. J Am Coll Nutr. 2009;28(5):525-542.

Montgomery P, Richardson AJ. Omega-3 fatty acids for bipolar disorder. Cochrane Database Syst Rev. 2008 Apr 16;(2):CD005169.

Sarris J et al. Omega-3 for bipolar disorder: meta-analyses of use in mania and bipolar depression. J Clin Psychiatry. 2012;73(1):81-86.

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