In a related editorial, the author commented that the results appear to be “highly promising” but cautioned that the dose of fatty acids used in the trial was around 15-20 times higher than the average US intake from foods. The author added that “It is imperative to ensure that this dose had no adverse effects on behaviour, cognition or other long-term outcomes,” and that further work should determine whether lower doses were effective.
A pre-specified subgroup analysis indicated that the reduction in wheeze and asthma was greatest in children born to women whose blood concentrations of the two major n-3 long-chain polyunsaturated fatty acids in the fish oil supplements (eicosapentaenoic acid and docosahexaenoic acid) were in the lowest third of the trial population at randomisation (17.5% v 34.1%; hazard ratio 0.46 (0.25 to 0.83); P=0.011).