Associations of whole blood n-3 and n-6 polyunsaturated fatty acids with blood pressure in children and adolescents -results from the IDEFICS/I.Family cohort

Background : Polyunsaturated n-3 and n-6 polyunsaturated fatty acids (PUFA) are precursors of biologically active metabolites that affect blood pressure (BP) regulation. This study investigated the association of n-3 and n-6 PUFA and BP in children and adolescents. Methods : In a subsample of 1267 children aged 2-9 years at baseline of the European IDEFICS (Identification and prevention of dietary-and lifestyle-induced health effects in children and infants) cohort whole blood fatty acids were measured by a validated gas chromatographic method. Systolic and diastolic BP was measured at baseline and after two and six years. Mixed-effects models were used to assess the associations between fatty acids at baseline and BP z-scores over time adjusting for relevant covariables. Models were further estimated stratified by sex and weight status. Results : The baseline level of arachidonic acid was positively associated with subsequent systolic BP (beta = 0.08, P = 0.002) and diastolic BP (beta = 0.07, P< 0.001). In thin/normal weight children, baseline alpha-linolenic (beta = -1.13, P = 0.003) and eicosapentaenoic acid (beta = -0.85, P = 0.003) levels were inversely related to baseline and also to subsequent systolic BP and alpha-linolenic acid to subsequent diastolic BP. In overweight/obese children, baseline eicosapentaenoic acid level was positively associated with baseline diastolic BP (beta = 0.54, P = 0.005). Conclusions : Low blood arachidonic acid levels in the whole sample and high n-3 PUFA levels in thin/normal weight children are associated with lower and therefore healthier BP. The beneficial effects of high n-3 PUFA on BP were not observed in overweight/obese children, suggesting that they may have been overlaid by the unfavorable effects of excess weight.