31 March 2015 - MedicalXpress - Understanding fish oil benefits during pregnancy

Supplementing polyunsaturated fatty acids during pregnancy and early development has shown to be potentially beneficial in preventing allergic, cardiovascular and metabolic disorders in children.

Professor Susan Prescott says while researchers know diet can affect many biochemical and physiological properties of cells and organs, the exact molecular mechanism that explains fish oil's health power is not well understood.

For this reason, she and her team examined the epigenetic mechanism of DNA methylation, an enzyme process that helps dictate gene expression by acting as a signalling tool to cells to silence certain genes.

To do so, they compared 36 mother-infant pairs who had taken fish oil supplements from 20 weeks of pregnancy until delivery and 34 who had not, isolating DNA from CD4+ T-cells and screening for methylation status across the whole genome at individual sites (CpG sites).

Methylation of cytosine at CpG sites can turn the gene off, so differences in activity in the test group would suggest this is the key mechanism behind fish oil health benefits.

"Basically we did not see any major differences when we compared the two groups,"

Prof Prescott says.

"For this reason we concluded that, while fish oil does appear to have beneficial effects on immune function, this does not appear to be mediated by major epigenetic changes at least in this population.

"It points to other mechanisms underpinning the beneficial effects of maternal fish oil intake on the offspring."

Prof Prescott says future research should examine how maternal fish oil intake influences the gut microbiome of their progeny and other anti-inflammatory pathways.