Letter to the editor regarding "Omega-3 fats in pregnancy: could a targeted approach lead to better metabolic health for children?".

The purpose of our letter to the editor is to offer additional perspective regarding 4 statements that do not fully represent the totality of the available scientific evidence. The 4 statements are as follows: (1) "Multiple studies have shown that n-3 PUFA products frequently have less n-3 PUFA content than labelled"; (2) "Recently, krill oil supplementation was shown to induce insulin resistance, indicating that it is potentially harmful"; (3) "… fish oil products are frequently oxidized at the time of purchase"; and (4) "In rats, supplementation with oxidized fish oil during pregnancy induced persistent maternal insulin resistance and increased neonatal mortality rate." We respectfully request the authors' future publications consider the totality of the available scientific evidence.

Chemical Compositional Changes in Over-Oxidized Fish Oils.

A recent study has reported that the administration during gestation of a highly rancid hoki liver oil, obtained by oxidation through sustained exposure to oxygen gas and incident light for 30 days, causes newborn mortality in rats. This effect was attributed to lipid hydroperoxides formed in the omega-3 long-chain polyunsaturated fatty acid-rich oil, while other chemical changes in the damaged oil were overlooked. In the present study, the oxidation condition employed to damage the hoki liver oil was replicated, and the extreme rancidity was confirmed.