Maternal fish oil supplementation during lactation is associated with reduced height at 13 years of age and higher blood pressure in boys only

Abstract

Dietary long-chain n-3 PUFA (n-3 LCPUFA) in infancy may have long-term effects on lifestyle disease risk. The present follow-up study investigated whether maternal fish oil (FO) supplementation during lactation affected growth and blood pressure in adolescents and whether the effects differed between boys and girls. Mother-infant pairs (n 103) completed a randomised controlled trial with FO (1.5 g/d n-3 LCPUFA) or olive oil (OO) supplements during the first 4 months of lactation; forty-seven mother-infant pairs with high fish intake were followed-up for 4 months as the reference group. We also followed-up 100 children with assessment of growth, blood pressure, diet by FFQ and physical activity by 7-d accelerometry at 13.5 (SD 0.4) years of age. Dried whole-blood fatty acid composition was analysed in a subgroup (n 49). At 13 years of age, whole-blood n-3 LCPUFA, diet, physical activity and body composition did not differ between the three groups. The children from the FO group were 3.4 (95% CI 0.2, 6.6) cm shorter (P = 0.035) than those from the OO group, and tended to have less advanced puberty (P= 0.068), which explained the difference in height. There was a sex-specific effect on diastolic blood pressure (P-sex x group = 0.020), which was driven by a 3.9 (95% CI 0.2, 7.5) mmHg higher diastolic blood pressure in the FO compared with the OO group among boys only (P= 0.041). Our results indicate that early n-3 LCPUFA intake may reduce height in early adolescence due to a delay in pubertal maturation and increase blood pressure specifically in boys, thereby tending to counteract existing sex differences.