Most of the fish oil/IQ links I know tend to either be poor quality studies, show no effect, or show a fade-out... For example,
> Supplementation of a mother’s diet during late pregnancy and 3 months postpartum with long-chained fatty acids has also been demonstrated to improve cognitive performance in human children (Helland et al. 2003). http://www.pediatricsdigest.mobi/content/111/1/e39.full
> CONCLUSION. This study suggests that maternal concentration of n-3 very-long-chain polyunsaturated fatty acids during pregnancy might be of importance for later cognitive function, such as sequential processing, although we observed no significant effect of n-3 fatty acid intervention on global IQs. Neonatal fatty acid status had no influence on BMI at 7 years of age.
(One may not be surprised inasmuch as most efforts to boost IQ in kids
like the Abecedarian project show fadeout.)
> Supplementation of a mother’s diet during late pregnancy and 3 months postpartum with long-chained fatty acids has also been demonstrated to improve cognitive performance in human children (Helland et al. 2003). http://www.pediatricsdigest.mobi/content/111/1/e39.full
But to follow up: Helland et al 2008 http://pediatrics.aappublications.org/content/122/2/e472.sho...
> CONCLUSION. This study suggests that maternal concentration of n-3 very-long-chain polyunsaturated fatty acids during pregnancy might be of importance for later cognitive function, such as sequential processing, although we observed no significant effect of n-3 fatty acid intervention on global IQs. Neonatal fatty acid status had no influence on BMI at 7 years of age.
(One may not be surprised inasmuch as most efforts to boost IQ in kids like the Abecedarian project show fadeout.)