Background: Blood pressure tracks from childhood into adulthood, and early diet may have long-term effects on hypertension.
Objective: The study's aim was to investigate whether intakes of n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) during lactation and current intakes of macronutrients affect blood pressure in 2.5-y-old Danish children.
Design: Mothers (n =122) with low fish intakes were randomly assigned to receive supplementation with 4.5 g fish oil or olive oil/d during the first 4 mo of lactation. The trial also included 53 mothers with high fish intakes. One hundred five of these women's children attended a 2.5-y follow-up examination at which anthropometric data and blood pressure were obtained. Mothers then kept a 7-d dietary record of food consumed by their children. A full set of data from 73 children was analyzed for effects of fish oil supplementation and cross-sectional correlations with current diet.
Results: We found no significant effect of the mothers' fish oil intakes during the first 4 mo of lactation on the blood pressure of the children 2.5 y later. Greater protein intakes measured as a percentage of energy were associated cross-sectionally with significantly lower diastolic and systolic blood pressures in the children at age 2.5 y after control for outdoor temperature, age, sex, weight, and height (P = 0.028 and 0.035, respectively). Greater protein intakes measured as g/d were also associated with significantly lower systolic blood pressures (P = 0.008). A 1-SD increase in protein intake corresponded with a decrease of approximately 3 mm Hg in systolic blood pressure.
Conclusion: The blood pressure of young Danish children was not significantly affected by intakes of n-3 LC-PUFAs via breast milk, but greater protein intakes at 2.5 y were associated with lower blood pressure.