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The effects of fish oil on mental health

Kevin Song

October 5, 2009




As a natural supplement, fish oil provides many of the essential nutrients needed to sustain good health. However, as an alternative medicine, the effects of fish oil on brain health have not been extensively recorded or studied until the past few years. While many fish oil supplements on the market generally cite personal experiences or the so-called “physicians” as proof of the benefits of fish oil on cognitive functions, they nevertheless omit respectable scientific researches in the field. Therefore, it is worthwhile to investigate what claims and supports the supplemental companies make about fish oil – whether fish oil does truly produce such miraculous effects as marketed. Furthermore, one needs to analyze the scientific researches on fish oil to critically examine the claims made by the internet market. On the whole, if scientific research indeed affirms the benefits of fish oil on mental health, then it may be worthwhile to recommend fish oil as a form of preventative measures against mental illnesses.

The Internet Market for Fish Oil

        Most fish oil supplements on the market come in the form of soft gel capsules. In regards to mental functions of fish oil, all supplemental companies make beneficial claims such as improving memory and elevating personality, mood, and mental disorders (Woynjarowski, 2006). While different products emphasize their own unique experiences such as higher purity or more doses, the overarching theme seems to embody the improvement of brain and heart health (Omega Q Plus, n.d.).

Majority of the products on the internet do not fully explain the mechanism by which fish oil helps to improve physical and mental health. In all cases, they attribute the importance of fish oil to 2 types of omega-3 fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexanoic acid), that “are ‘good fats’ and extremely vital to health” (See Change Nutraceuticals, 2009). But beyond the superficial explanations, companies do not indicate how the DHA and EPA exactly impact health.

FocusFactor (2009) Instead they tend to use verbose descriptions to attract potential customers. For instance, commercialized product FocusFactor (2009) advertises “proprietary neuro-boosters that help support your memory” but fails to explain how the boosters work. Similarly, substitute product Omega Q Plus (n.d.) integrates florid phrases such as “a new grade of ultra-rich, cardio quality fish oil,” “breakthrough form of Coenzyme Q10,” and “5 more superstar…cutting edge heart-health nutrients” to entice buyers. Moreover, companies rely on colorful graphics and charts to illustrate their point. For instance, the graph on the right shows no legend or any description explaining the data. For all purposes, it serves only to entertain the consumers and provides no solid evidence to support the product. After all, utilizing catchy, scientific phrases, the supplement companies confound people into buying their products. As marketing strategy goes, perhaps the majority of the public would not be able to comprehend the mechanism even if it were explained. So the companies find it useless to try.

Instead, companies offer a plethora of evidences ranging from success stories to physician approval to support their claims. Personal testimonies remain one of the most common forms of backings. See Change Nutraceuticals (2009) contains many success stories such as this one:

“I've used other omega-3 products in the past and did not notice a difference in myself. With your product, Omega-3 Life Support, I do! I am a 54-years-young registered nursing student and need all the extra clear thinking and good health I can get... thank you again for providing a pure product.”
Dianne, Age 54, Tallahassee, FL

Likewise, Esther Marie Versch posts on Omega Q Plus (n.d.): “After taking your regular CoQ10 my husband and I decided we wanted to try your Omega Q Plus! We don’t have to buy the fish oil—it's already in it! We feel we have more energy.” In the personal testimonies, people can relate to the success of others and thus are more willing to purchase the products. Also, some websites turn to endorsement of physicians for support. They often show pictures of nameless physicians such as the one on left without any descriptions of physicians’ backgrounds or training (FocusFactor, 2009). Moreover, websites such as Omega Q Plus (n.d.), in an effort to assert their claims, list physician, Stephen Sinatra, M.D., as one of the creators of the product. As far as the general public is concerned, if a doctor endorses the product, it must be useful. Yet, without a substantial investigation, it would be difficult to determine the credential of a particular doctor. In this, even listing physicians does not constitute as good support.

Furthermore, companies mention the results from clinical studies as a form of evidence. They do so through phrases such as “studies have shown” and “scientific evidence gathered” (Woynjarowski, 2006; FocusFactor, 2009). Nevertheless, a quick glance across the genre shows that rarely do the websites cite the references they are alluding to. Therefore, it becomes difficult to ascertain whether the companies have creditable proof. However, there are exceptions. Notably, Xtend-life (2009) provides detailed citations of clinical studies to support the benefits of fish oil. In this case, the scientific literature constitutes as a great source of evidence. Lastly, some companies rely on the bandwagon of mass consumerism for reinforcement. FocusFactor (2009) bluntly indicates on its website that it is “America’s #1 selling memory supplement over 4,150,738 sold!” The bandwagon approach appeals to the public in the same way as the personal testimonies. If millions of people buy FocusFactor, it must be working. Yet, as with previous strategies, the difficulties of confirming the data reduce the quality of evidence of the product.

Incidentally, the disclaimers on the websites further damage the authority of the products. To illustrate, See Change Nutraceuticals (2009) posts a statement in small font: “The products and the claims made about specific products on or through this site have not been evaluated by the United States Food and Drug Administration and are not approved to diagnose, treat, cure or prevent disease.” Ironically, even after accumulating the overwhelming amount of “supporting evidence,” the companies themselves, not to mention the FDA, have doubts whether their products would work.
        Indicative of the general poor quality of evidence and the lack of mechanism and grounding, I believe that the companies’ only goal is to maximize profit in the market. They worry less about providing sound evidence and guidance for the public to make an informed decision about the benefits of fish oil; instead the sellers focus more on attracting potential buyers through pretentious exaggerations. Thus, it is importance to verify the companies’ claims of fish oil benefits through scientific researches.
Clinical Studies on Fish Oil
        In regards to the potential benefits, a breadth of clinical studies have linked fish oil to cognitive health. Moriguchi and Salem (2003) tracked the spatial task performance of genetically mutated mice fed with vegetable oil-based versus fish oil-based formulas through a 7-week span and demonstrated that “Infants fed vegetable oil-based formulas may have poorer visual function, lower cognitive scores and acquire learning tasks more slowly in comparison with those breast fed or those fed formulas supplemented with DHA.” This is, the adverse effects of brain development due to DHA deficiency may be reversed by a supplemental diet of fish oil. In a separate but similar experiment, Dalton et al. (2009) randomly assigned “subjects (n=183) to an experimental (n=91) and control group (n=92), receiving either the fish-flour spread or a placebo spread for 6 months in a single-blind study.” In the end, they found that an omega-3 fatty acid supplemental diet led to an improvement of verbal learning ability and memory of children. Furthermore, Chung, Chen, and Su (2008) also supported the importance of a DHA diet. In their experimental design, Rats fed the omega-3 fatty acid-deficient diet showed significantly poorer reference and working memory, and fish oil supplementation partially rescued both memory performances. Furthermore, fish oil supplementation during brain development and adulthood in normal rats resulted in significant enhancement of both memories (Chung, Chen, & Su, 2008). Thus in three separate experiments, the results suggest that a fish oil diet is critical for the development and maintenance of learning memory performance.
        Scientific literature also discusses the positive contribution of fish oil to mood disorder such as depression. For instance, in their review paper, Parker et al. (2006) analyzed the conclusions drawn from 61 articles – “several epidemiological studies that suggested covariation between seafood consumption and rates of mood disorders, biological marker studies that indicated deficits in omega-3 fatty acids in people with depressive disorders, and several treatment studies that indicated therapeutic benefits from omega-3 supplementation.” Parker et al. (2006) concluded that “deficits in dietary-based omega-3 polyunsaturated fatty acids may make an etiological contribution to mood disorders” and that future studies that focus on supplementation with omega-3 fatty acids may provide the greatest benefit.
        In the end, scientific researchers have correlated fish oil supplements with memory development, maintenance, and positive mental functions. However, at this time, ongoing researches are conducted to identify the biological pathway by which omega-3 fatty acid works through. One plausible hypothesis suggests that “fatty acids contribute to the healthy formation of the brain’s never cell membranes and membrane fluidity” (Parker et al., 2006). In this way, fish oil helps to maintain brain functions. Furthermore, as the supplemental and medical value goes, future work are directed toward determining which omega-3 fatty acid (DHA or EHA) is likely to have the greatest benefit and at what dose (Parker et al., 2006).
        As researches have suggested, fish oil has an overwhelming correlation to mental health. Indicative of this, in the supplementary market, fish oil constitutes a great source of profit for companies who compete against each other for potential customers. They support their product through various evidences such as personal testimony, consumer bandwagon, and physician endorsements. However, rarely do companies actually generate credible data to sustain their arguments. While they have not made unreasonable claims about their products, the evidences produced by the companies prove to be poor in quality. In the scientific community, an enormous compilation of evidence has pointed to the benefits of fish oil for both physical and mental health. For future investigations, scientists are focusing on exploring the intriguing prospect of using fish oil as an alternative medicine as such the treatment of depression symptoms. But for now, taken as a supplement, fish oil may indeed prove to be beneficial for one’s mental and physical health.


Chung, W., Chen, J., & Su, H. (2008). Fish oil supplementation of control and (n-3) fatty acid-deficient male rats enhances reference and working memory performance and increases brain regional docosahexaenoic acid levels. J Nutr. 138(6). Retrieved from

Dalton, A., Wolmarans, P., Witthuhn, R., van Stuijvenberg, M., Swanevelder S., & Smuts C. (2009). A randomised control trial in schoolchildren showed improvement in cognitive function after consuming a bread spread, containing fish flour from a marine source. Prostaglandins Leukot Essent Fatty Acids. 80(2-3). Retrieved from

FocusFactor. (2009). Retrieved from

Moriguchi, T., & Salem, N. Jr. (2003). Recovery of brain docosahexaenoate leads to recovery of spatial task performance. J Neurochem. 87(2). Retrieved from

Omega Q Plus. (n.d.) Retrieved from

Parker, G., Gibson, N., Brotchie, H., Heruc, G., Rees, A., & Hadzi-Pavlovic, D. (2006). Omega-3 fatty acids and mood disorders. Am J Psychiatry. (163)10. Retrieved from

See Change Nutraceuticals. (2009). Retrieved from

Woynjarowski, Dave (2006). Truth about Fish Oil. Retrieved from

Xtend-life. (2009). Retrieved from





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