Fish oil for a healthy brain?

Human head from side, showing the brain in activity.

The benefits of fish oil for cardiovascular health are common knowledge, but the fact that fish oil is also very beneficial for brain health is not that well known. Roughly eight per-cent of the brain mass is made up of the Omega-3 fatty acids, Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), the two main constituents of fish oil. The brain gets its benefits mostly from DHA, and to a lesser degree from EPA. DHA is the main component making up the cerebral cortex portion of the brain; the area dealing with emotion, attention, memory among other things. DHA and EPA also play a major role in a number of other tasks including function of neurons in the brain, protection against oxidative damage, production of new brain cells and protection against inflammation. Recent discoveries have shown that the balance of these fatty acids in the brain aids in establishing if a brain cell will be protected from inflammation and damage or succumb to disease.1

According to large epidemiology studies, people suffering from depression tend to have lower levels of DHA and EPA in the blood.2, 3 Furthermore, an autopsy study conducted on brains of people known to have suffered from depression showed lower amounts of Omega’-3s than who were not depressed.4  In fact people with greater amounts of Omega-3s tend to have larger brains.

Bipolar disorder is a puzzling condition in which patients swing between periods of deep depression and euphoria along with disproportionate activity or mania. In some people the mood swings are rapid while in others they are slower and still others there is no manic elements at all. People who take greater quantities of seafood, hence Omega-3s, appear to be protected from bipolar symptoms.5 Additionally autopsy studies of people with bipolar disorder showed shortage of DHA in brain cells and elevations in inflammatory elements, which would have been curbed had DHA levels been normal.6

New data hints that aggressive and criminal behaviour is closely associated with low levels of Omega-3s in the blood which is also allied with diminished levels of honesty, humanity and self-discipline. It is believed that this may be due to the changes in serotonin yields, the chemical responsible for controlling aggression, hostility and impulsive behaviours.7 Studies show that autistic children treated with EPA and DHA supplements showed improvement in tantrums, and self-injurious behaviour compared to those given placebo.8 Other data shows that Omega-3 supplements could yield promising results in treating aggression and hostility without any negative side effects.

Numerous studies show a strong association between reduced intake of Omega-3s and lessening of brain synapses, memory, and learning abilities. Furthermore, individuals with diminished levels of Omega-3s might be more susceptible to cognitive issues such as ADHD, dyslexia and cognitive decline.9


  1. De Vriese SR, Christophe AB, Maes M. In humans, the seasonal variation in poly-unsaturated fatty acids is related to the seasonal variation in violent suicide and serotonergic markers of violent suicide. Prostaglandins Leukot Essent Fatty Acids. 2004 Jul;71(1):13-8.
  2. Peet M, Murphy B, Shay J, Horrobin D. Depletion of omega-3 fatty acid levels in red blood cell membranes of depressive patients. Biol Psychiatry. 1998 Mar 1;43(5):315-9.
  3. Maes M, Christophe A, Delanghe J, Altamura C, Neels H, Meltzer HY. Lowered omega3 polyunsaturated fatty acids in serum phospholipids and cholesteryl esters of depressed patients. Psychiatry Res. 1999 Mar 22;85(3):275-91.
  4. McNamara RK, Hahn CG, Jandacek R, et al. Selective deficits in the omega-3 fatty acid docosahexaenoic acid in the postmortem orbitofrontal cortex of patients with major depressive disorder. Biol Psychiatry. 2007 Jul 1;62(1):17-24.
  5. Noaghiul S, Hibbeln JR. Cross-national comparisons of seafood consumption and rates of bipolar disorders. Am J Psychiatry. 2003 Dec;160(12):2222-7.
  6. McNamara RK, Jandacek R, Rider T, et al. Deficits in docosahexaenoic acid and associated elevations in the metabolism of arachidonic acid and saturated fatty acids in the postmortem orbitofrontal cortex of patients with bipolar disorder. Psychiatry Res. 2008 Sep 30;160(3):285-99.
  7. Mincke E, Cosyns P, Christophe AB, De Vriese S, Maes M. Lower omega-3 polyunsaturated fatty acids and lower docosahexaenoic acid in men with pedophilia. Neuro Endocrinol Lett. 2006 Dec;27(6):719-23.
  8. Amminger GP, Berger GE, Schafer MR, Klier C, Friedrich MH, Feucht M. Omega-3 fatty acids supplementation in children with autism: a double-blind randomized, placebo-controlled pilot study. Biol Psychiatry. 2007 Feb 15;61(4):551-3.
  9. Laasonen M, Hokkanen L, Leppamaki S, Tani P, Erkkila AT. Project DyAdd: Fatty acids and cognition in adults with dyslexia, ADHD, or both. Prostaglandins Leukot Essent Fatty Acids. 2009 Jul;81(1):79-88.
Categorized as Blog

By Andy

Hi, my name is Dr. Andy Williams and I am a biologist with a keen interest in diet and nutrition. This site was set up to help me explore the research, facts and fiction about Krill Oil. Please feel free to contact me if you have any comments, questions or suggestions.

Leave a comment

Your email address will not be published. Required fields are marked *

6 + twelve =