And to keep you up to date, we asked expert attendee Joyce Nettleton, D.Sc., to summarize ISSFAL presentations that addressed various topics, including brain, heart, and metabolic health.
Dr. Nettleton is a widely published expert on omega-3 science and seafood health-nutrition topics who issues regular research updates in the Fats of Life (consumer-oriented) and PUFA (scientist-oriented) e-newsletters.
Omega-3s and Mental Health: A Report from ISSFAL 2010
By Joyce A. Nettleton, D.Sc.
Folklore has long held that fish is brain food… a belief increasingly bolstered by scientific evidence.
The APA’s expert panel concluded that abundant intake of omega-3s from seafood (DHA and EPA) helps support mental health... and that the evidence warrants urgent research designed to better define omega-3s’ potential to prevent or treat specific mental problems.
Their positive position was based on what’s already known about key brain structures and functions—which rely heavily on omega-3 DHA—and an emerging body of evidence concerning omega-3s and mental conditions.
Our brains are mostly fat, and more than half of that heady stuff is omega-3 DHA.
We must have omega-3 DHA and EPA to survive or thrive, and can only obtain them in two ways:
Easily and abundantly from fish (especially fatty fish like sardines, tuna, and salmon).
Make small amount in our bodies from plant-form omega-3 ALA, in a very inefficient conversion process that’s hindered further by the flood of competing omega-6 fats, which Americans consume in unhealthful excess (ALA is most abundant in walnuts, flax or hemp seed, leafy greens, beans, and grass-fed livestock).
The APA panel also relied on the evidence existing then (in 2007). This included cell and animal studies, some preliminary clinical trials … and a larger number of epidemiological studies, in which scientists survey or follow groups of people, looking for any associations between health and diet.
Large, well-controlled clinical trials are the evidentiary gold standard, but because omega-3s are practically un-patentable products, therefore holding little profit potential, they rarely get funded by drug firms.
And costly clinical trials won’t get government funding without a persuasive body of lab and epidemiological evidence … a tipping point the APA panel thought we’d passed three years ago.
Here’s my summary of new and recent evidence concerning omega-3s and three major mental conditions (depression, suicide, and schizophrenia)… including papers presented at ISSFAL by the researchers themselves.
Some, but not all, studies have detected significant symptomatic improvements in people diagnosed with major depression who consumed modest amounts of omega-3s from fish (EPA and DHA)… with or without medication.
There is some evidence suggesting that omega-3 EPA may be more effective than omega-3 DHA or both together, but this possibility requires additional research.
Last summer, French researchers reported the results of a clinical trial involving 432 patients with depression, half of whom also had anxiety disorder. [Editor’s note: We covered this report in a prior issue of Vital Choices; see “Fish Oil Rivals Antidepressants in Clinical Trial”.]
The patients were given about 1 gram per day of EPA or placebo for 8 weeks (St-André E et al., 2010; Lesperance F et al. 2010).
At the end of the treatment there were no differences in assessment scores between the two groups.
However, when the analysis excluded patients with anxiety disorder, EPA was associated with a significant improvement in depressive symptoms.
And in a study of pregnant women diagnosed with anxiety and depression, researchers observed that having higher levels of anxiety, but not depression, was associated with lower blood levels of omega-3 and omega-6 fatty acids (Bartke N et al. 2010).
Women with lower blood levels of omega-3 and omega-6 fatty acids and anxiety or depression also had shorter gestation times, attributable in part to their low omega-3 and omega-6 status.
One of the most intriguing ISSFAL presentations noted that suicide deaths in the US military now outnumber the deaths from combat in current US engagements. The military suicide rate overall recently exceeded the civilian rate, for the first time since records have been kept.
A team of investigators that included renowned research psychiatrist Joseph Hibbeln, M.D.—from the National Institute on Alcohol Abuse and Alcoholism—proposed that low omega-3 status might increase the risk of depression and suicide in the US military. [Editor’s note: For more about Dr. Hibbeln’s work, see “‘Captain of the Happier Meal’ Gets a Salute”.]
To test this idea, they measured the long-chain omega-3s in the blood of 800 active duty suicide individuals and matched their leading characteristics to 800 controls (Hibbeln J et al., 2010).
The team’s analysis indicated that those with the highest levels of DHA were significantly less likely to die by suicide than those with the lowest levels.
An important contributing factor to suicide was the experience of seeing a soldier wounded or killed.
These observations suggest that low DHA status may be a risk factor for suicide, but might be overturned by dietary intervention… a possibility these investigators hope to test.
The ISSFAL presentations included a report of research in Tunisian schizophrenics, which supported the prior observation that individuals with schizophrenia have significantly lower levels of omega-6 ARA and omega-3 DHA in their red blood cells compared with non-schizophrenic individuals (Feki M et al. 2010).
Both of these fatty acids are essential to brain function, and blood levels fell as the severity of the symptoms increased… adding yet more evidence that deficits in long-chain omega-3 and omega-6 fatty acids occur in schizophrenic patients, and that disease severity increases as blood levels drop.
The Tunisian findings fit with a University of Cincinnati study, which showed that DHA levels in the orbito-frontal cortex brain region are lower in people with schizophrenia, compared with normal individuals (McNamara RK et al., 2007).
And evidence is growing that different psychiatric disorders may be related to DHA deficits in different regions of the brain.
For example, when researchers from the National Institute on Alcohol Abuse and Alcoholism measured omega-3 levels in the brain’s hippocampus region, they found no significant differences between mentally healthy people and patients with schizophrenia or bipolar disorder (Hamazaki H et al., 2010).
We may lack irrefutable proof that dietary omega-3s provide significant preventive or therapeutic benefits for the manor mental health conditions.
But the scientists at ISSFAL certainly recommend urgent research into the effects of dietary fats on mental health… especially omega-3s and America’s badly skewed omega-3/omega-6 intake balance.
Bartke N, Hoesli I, Urech C et al. Low levels of ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) in pregnancy: association with anxiety and depression. Poster. ISSFAL 2010, Maastricht, Netherlands. P 142.
Brenna JT, Diau GY. The influence of dietary docosahexaenoic acid and arachidonic acid on central nervous system polyunsaturated fatty acid composition. Prostaglandins Leukot Essent Fatty Acids 2007;77:247-250.
Cao D, Kevala K, Kim J, et al. Docosahexaenoic acid promotes hippocampal neuronal development and synaptic function. J Neurochem 2009;111:510-521.
Chang CY, Ke DS, Chen JY. Essential fatty acids and human brain. Acta Neurol Taiwan 2009:18:231-241.
Feki J, Sethom, Bouaziz N et al. Arachidonic and docosahexaenoic acids deficits are associated with negative symptoms of schizophrenia. Poster. ISSFAL 2010, Maastricht, Netherlands. P 128.
Gow RV, Sumich A, Rubia K et al. The relationship between measures of depression, anxiety and anger/disruptive behavior and omega-3/6 fatty acids in adolescents with and without ADHD. Abstract. ISSFAL 2010, Maastricht, Netherlands. P 115.
Hamazaki K, Choi KH, Kim HY. Phospholipid profile in the postmortem hippocampus of patients with schizophrenia and bipolar disorder. Poster. ISSFAL 2010, Maastricht, Netherlands. P 75.
Hibbeln JR, Lewis M, Johnson J et al. Low omega-3 fatty acid status and increased risk of suicide death among active duty U.S. military: a case control comparison. Poster. ISSFAL 2010, Maastricht, Netherlands. P 192.
Hibbeln JR. Depression, suicide and deficiencies of omega-3 essential fatty acids in modern diets. World Rev Nutr Diet. 2009;99:17-30. Epub 2009 Jan 9. Review. No abstract available.
Hibbeln JR. From homicide to happiness--a commentary on omega-3 fatty acids in human society. Cleave Award Lecture. Nutr Health. 2007;19(1-2):9-19.PMID: 18309762
Kim HY, Lee J, Cao D, Xiong ZM. Metabolism of docosahexaenoic acid in hippocampal development. Abstract. ISSFAL 2010, Maastricht, Netherlands. P 52.
Lesperance F et al. The efficacy of eicosapentaenoic acid for major depression: Results of the OMEGA-3D trial. 9th World Congress of Biological Psychiatry: Abstract FC-25-005. Presented July 1, 2009. Accessed at http://www.wfsbp-congress.org/fileadmin/user_upload/WFSBP_Final_Programme_090625.pdf
Levant B, Zarcone TJ, Fowler SC (a). Developmental effects of dietary n-3 fatty acids on activity and response to novelty. Physiol Behav 2010; [Epub ahead of print]
Levant B, Zarcone TJ, Fowler SC (b). Effects of dietary n-3 fatty acids and brain DHA content on activity and response to novelty in the developing rat. Abstract. ISSFAL 2010, Maastricht, Netherlands. P 114.
McNamara RK, Jandacek R, Rider T et al. Abnormalities in the fatty acid composition of the postmortem orbitofrontal cortex of schizophrenic patients: gender differences and partial normalization with antipsychotic medications. Schizophr Res 2007;91:37-50.
St. André E, Lesperance F, Frasure-Smith N, et al. Efficacy of essential fatty acid EPA in treatment of major depressive disorder: a large placebo control study. Poster. ISSFAL 2010, Maastricht, Netherlands. P 132.
Sublette ME, Hibbeln JR, Galfalvy H, Oquendo MA, Mann JJ. Omega-3 polyunsaturated essential fatty acid status as a predictor of future suicide risk. Am J Psychiatry. 2006 Jun;163(6):1100-2.