Fish oil supplementation, maternal genotype linked with childhood atopic dermatitis

Key takeaways:

• Results showed that fish oil supplementation was associated with metabolites linked to inflammation.
• This finding was only relevant in mothers with the COX1 rs1330344 TT genotype.

Fish oil supplementation during pregnancy was associated with children having a lower or higher risk for developing atopic dermatitis depending on the mother’s genotype, according to a study.

“Atopic dermatitis usually debuts during early childhood, and interventions during pregnancy are considered promising for primary prevention of AD,” Liang Chen, MSc, a PhD student at Copenhagen Prospective Studies on Asthma in Childhood at the University of Copenhagen, and colleagues wrote. “It has been suggested that omega-3 long-chain polyunsaturated fatty acids (n-3 LCPUFAs; ie, fish oil) are associated with reduced risk of atopic diseases by suppressing inflammatory processes, particularly through altering eicosanoids.”

Chen and colleagues conducted a prespecified secondary analysis of a randomized clinical trial that included 635 mother-child pairs from the Danish Copenhagen Prospective Studies on Asthma in Childhood 2010 birth cohort. These mothers were randomly assigned to receive either the fish oil (n = 321) or placebo (n = 314) daily until 1 week postpartum.

Results showed that supplementation with fish oil was associated with lower urinary thromboxane A2 (TXA2) metabolites in children aged 1 year (beta = –0.46; 95% CI, –0.8 to –0.13). This is significant because TXA2 pathway eicosanoids originate from the cyclooxygenase-1 (COX1) enzyme, which is associated with chronic inflammation in AD. Furthermore, prior studies have found that elevated levels of TXA2 in early life are associated with the development of AD later.

On the other hand, fish oil supplementation (HR = 1; 95% CI, 0.76-1.33) and maternal COX1 genotype (HR = 0.94; 95% CI, 0.74-1.19) individually were not associated with a risk for AD in children until age 10 years. However, there was an interaction between these variables, according to the study (P < .001).

Out of the three types of COX1 genotypes that a mother could have, the children born to mothers with the TT genotype that also took fish oil saw a reduced risk for AD vs. those in the same genotype category born to mothers who did not take the supplement (HR = 0.7; 95% CI, 0.5-0.98).

Children of those with the CT genotype saw no association in AD risk (HR = 1.29; 95% CI, 0.79-2.1) whereas children of mothers with the CC genotype experienced a significantly higher risk (HR = 5.77; 95% CI, 1.63-20.47).

According to the authors, these findings indicate that fish oil supplementation during pregnancy was associated with risk for childhood AD at age 10 years only for mothers with a certain genotype.

“These findings support the use of a personalized prevention strategy for reducing the burden of AD in childhood by only providing n-3 LCPUFA supplementation to pregnant mothers carrying the COX1 rs1330344 TT genotype,” the authors concluded.