A brief primer on Fish oil before going into the research. Fish oil is an omega-3 fatty acid(a polyunsaturated fat), which is essential for optimal health. It's two main components are EPA and DHA (both fatty acids), DHA acts to provides a fluidity to cell membranes and is integral to cell communication(in the brain). EPA on the other hand has more of a role in reducing inflammation and cardiovascular health. There are other sources of Omega-3, such as flax seed/oil, however, flax contains no EPA or DHA. The human body does have a series of enzymes called fatty acid desaturases which convert Flax (Alpha linolenic acid) into EPA/DHA, although the conversion is very inefficient, making fish oil supplementation ostensible necessary.
Fish oil has been researched for it's possible role in treating core autism symptoms. This concept was derived from the benefits fish oil provides and the unique cluster of issues ASD presents. The evidence:
- It has been reported by Vencassel et al and Bell et al that those on the spectrum have lower levels of polyunsaturated fats. This would indicate that supplementation with fish oil may have benefits and correct deficiency. (PMID: 11487301)
- However, other studies have failed to replicate this finding.PMID: 25798215
- Several open label studies went on to suggest a role for fish oil in reducing hyperactivity and improving language.
This initial basic research combined with the clinical effects of fish oil supplementation spurred numerous controlled trials.
- Amminger et al published a small study using 13 children with ASD and 1.5grams of fish oil. There was a trend for improving hyperactivity, it however did not reach clinical significance. The number of subjects was low as was the duration, only 6 weeks.
- Bent et al conducted a similar study only the testing period was extended to 27 weeks. Again there was a trend for improving hyperactivity, with no other measure improving.
- A Cochrane review in 2011, found no benefits for fish oil supplementation in ASD. The review did note that hyperactivity may be improved via supplementation
A brand new randomized placebo controlled study has been conducted just this month regarding ASD and fish oil supplementation.The findings are in line with the above, there appears to be marginal benefits with no improvement in core symptoms such as language, repetitive behaviour etc.
- The study found "no significant difference between groups on the 0- to 24-week change in PDDBI autism composite scores (p = 0.5)" along with a worsening score (regression) in some categories. There was no improvement noted in adaptive function or language as well. The authors conclude "This study does not support high dose supplementation of omega-3 fatty acids in young children with ASD."PMID: 25798215"
These findings mirror my clinical findings anecdotally, fish oil does not appear to improve core issues in ASD. With that said, it has a plethora of benefits for immune function, cardiovascular health and perhaps hyperactivity which should make it a staple supplement for most.