A recent study presented at the 2024 congress of EULAR has explored the potential association between maternal fish consumption or dietary mercury exposure during pregnancy and the risk of juvenile idiopathic arthritis.
The study utilized data from the Norwegian Mother, Father, and Child Cohort Study, which recruited pregnant women between 1999 and 2008. Juvenile idiopathic arthritis (JIA) cases were identified through linkage to the national patient registry. Maternal fish consumption was assessed using a food frequency questionnaire covering the first half of pregnancy, with high fish consumption defined as exceeding the 90th percentile for various fish categories. Dietary mercury exposure was estimated based on the fish consumption data, with high mercury intake classified as more than 20 μg per week.
The study sample included 73,819 mother-child pairs and 218 cases of JIA in the children. The results showed a positive association between JIA and high consumption of lean and semi-oily fish compared to low consumption. However, no clear associations were found between JIA and high consumption of oily fish, total fish, or high mercury intake.
"We found increased odds of JIA when the maternal intake exceeded 252 grams of lean or semi-oily fish per week compared with low intake. However, the magnitude of our effect estimates was substantially smaller than the Swedish study from 2019, and we found no association between total fish consumption or estimated dietary mercury exposure and JIA," noted study investigator Vilde Øverlien Dåstøl.
Dåstøl emphasized that while the data indicates an association, causation cannot be definitively inferred. The researcher cautioned against advising pregnant women to avoid consuming fish solely based on this study, considering other research highlighting the positive impacts of a marine diet.
The study's findings contributed to the ongoing research into the complex interplay of genetic and environmental factors in the development of JIA. Further research is needed to better understand the potential role of maternal diet in the risk of this rare autoimmune disease in children.
Conflict of interest disclosures were not made available at the time of publishing.