Dietary fatty acid composition during pregnancy and the risk of asthma in the offspring

BACKGROUND: Fatty acids (FA) modulate the immune system, and it has been proposed that they affect the incidence of IgE-mediated allergic diseases. We explored the association of maternal dietary FA composition during pregnancy with the risk of asthma in the offspring. METHODS: We analyzed data from the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) Nutrition Study. Maternal dietary intake during pregnancy (8th month) was assessed by a validated 181-item food frequency questionnaire. The occurrence of asthma was assessed at the age of 5 yr with a questionnaire modified from the International Study of Asthma and Allergies in Childhood (ISAAC). Cox proportional hazards regression was used for the statistical analyses. RESULTS: Low maternal intakes of α-linolenic acid (18:3n-3) [lowest quarter vs. mid-half HR 1.67 (95% CI 1.12-2.48)] and total n-3-polyunsaturated fatty acids (PUFA) [HR 1.66 (95% CI 1.11-2.48)] during pregnancy were associated with an increased risk of asthma in the offspring, while a low intake of arachidonic acid (20:4n-6) [HR 0.52 (95% CI 0.32-0.84)] and high intake of total saturated fatty acids [highest quarter vs. mid-half HR 0.55 (95% CI 0.34-0.90)] and palmitic acid (16:0) [HR 0.51 (95% CI 0.31-0.83)] were associated with a decreased risk of asthma. The ratios of n-6 to n-3-PUFA and 18:2n-6 to 18:3n-3, and the maternal intake of oils, fish and fish products, showed no association with the risk of asthma. The associations found were independent of several perinatal and clinical confounders. CONCLUSION: Maternal intake of FA during pregnancy was associated with childhood asthma. Maternal α-linolenic acid, total n-3 PUFA and palmitic acid intake may decrease, while arachidonic acid intake may increase the risk of asthma in the offspring.