Effect of docosahexaenoic acid supplementation on inflammatory cytokine levels in infants at high genetic risk for type 1 diabetes

Objective: Type 1 diabetes (T1D) results from the inflammatory destruction of pancreatic β-cells. In this study, we investigated the effect of docosahexaenoic acid (DHA) supplementation on stimulated inflammatory cytokine production in white blood cells (WBC) from infants with a high genetic risk for T1D. Research design and methods: This was a multicenter, two-arm, randomized, double-blind pilot trial of DHA supplementation, beginning either in the last trimester of pregnancy (41 infants) or in the first 5 months after birth (57 infants). Levels of DHA in infant and maternal red blood cell (RBC) membranes and in breast milk were analyzed by gas chromatography/mass spectrometry. Inflammatory cytokines were assayed from whole blood culture supernatants using the Luminex multiplex assay after stimulation with high dose lipopolysaccharide (LPS), 1 μg/mL. Results: The levels of RBC DHA were increased by 61-100% in treated compared to control infants at ages 6-36 months. There were no statistically significant reductions in production of the inflammatory cytokines, IL-1β, TNFα, or IL-12p40 at any of the six timepoints measured. The inflammatory marker, high-sensitivity C-reactive protein (hsCRP), was significantly lower in breast-fed DHA-treated infants compared to all formula-fed infants at the age of 12 months. Three infants (two received DHA) were removed from the study as a result of developing ≥two persistently positive biochemical islet autoantibodies. Conclusions: This pilot trial showed that supplementation of infant diets with DHA is safe and fulfilled the pre-study goal of increasing infant RBC DHA levels by at least 20%. Inflammatory cytokine production was not consistently reduced.