Are they any good?

In 2006, Equazen, a company that sells fish oil supplements donated to Durham city council enough pills to feed 3000 children for one year. Their aim was to assess if the supplements would enhance the performance of students and make a difference to the their GCSE scores. In the Guardian, Ben Goldacre pointed out that from the limited number of studies done on the efficacy of these pills, it was not clear whether the supplements are beneficial, have no effect or cause harm. He also suggested that, if the company is carrying out research on such a large scale, it might as well conduct it in a way that allows it to be considered as a proper ‘trial’ by having an equal number of students who were not given the pill (control group). The company paid no heed and nor did the city council persuade them. They went ahead with their plans and gave the children enough pills for the academic year 2007-08. A year later, the GCSE results were announced and instead of a better performance by the students, a decline in GCSE scores was observed (growth in the number of students gaining A* – C grades in 2006-07 was 5.5% and in 2007-08 it was only 3.5%). Eventually, the company made some dubious statements that received a lot of attention from the press and thus achieved their aim of advertising their product. Even then, Goldacre defended his case and stuck to his claims. Now in 2010, a double-blind study has been published in the journal, Review in Developmental Disabilities that investigates the efficacy of these supplements on normal school students.

It is well known that Omega-3 & Omega-6 fatty acids are essential for human health and because they cannot be made by the body, they have to be obtained from the diet. Here ‘essential’ implies that a certain amount is necessary for normal growth but not that more will only be beneficial. Yet, the industry markets this product as something that will increase ‘brain power’. Is that really the case?

The problem with answering this question is that there cannot be one certain answer for all human population. These supplements have different effects on people in different age groups or on people with or without mental disorders. Their role in cognition and development has been investigated in a number of studies. A prevalence of fatty acid deficiency symptoms was seen in children exhibiting hyperactive behaviour, attention deficit hyperactivity disorder (ADHD) and autism. In another study, it was shown that cognitive development of infants improved significantly when mothers were taking these supplements during pregnancy and lactation. Despite some positive results, their role in learning and behaviour still remains unclear as most studies lead to mixed or inconclusive results.

Yet, from previous studies we can be fairly sure that it is likely that the effect of these supplements is more pronounced in children with developmental disorders and therefore, their results may not be applicable to mainstream school children. The 2010 study set out to answer exactly this question. The 16-week long study was done in 450 school children aged 8-9 years. Eligibility criteria included having an IQ > 70. The thorough study included a number of cognitive tests that measured working memory, reading and spelling ability, and behaviour ratings that were obtained from feedback given by parents and teachers.

Results indicated a significant increase in the fatty acid concentration in the blood after the 16 week period in the active group compared to the placebo group. But cognitive tests and behaviour ratings showed no significant differences. The study concluded that even though this study has shown no benefits to students, it may not mean that there are no benefits at all. More work is necessary to further our understanding of the effects of these fatty acids in combination with vitamins and other micro-nutrients.

Most importantly though it goes on to show that Goldacre was right in being skeptical. Equazen could have saved the million pounds it spent on the pills for the students in Durham as it led to no benefits, and now we have proof.

Kirby, A., Woodward, A., Jackson, S., Wang, Y., & Crawford, M. (2010). A double-blind, placebo-controlled study investigating the effects of omega-3 supplementation in children aged 8–10 years from a mainstream school population Research in Developmental Disabilities, 31 (3), 718-730 DOI: 10.1016/j.ridd.2010.01.014