Evidence of infant blood pressure programming by maternal nutrition during pregnancy: a prospective randomized controlled intervention study
The underlying denominators of cardiovascular diseases, including obesity and hypertension, have extended to the pediatric population1, 2, warranting an understanding of how early environmental exposures exert their effects on these chronic diseases.
Nutrition in early life (even at the fetal stage) has been documented in several epidemiological and experimental studies as having an impact on cardiovascular diseases risk in later life and on the related risk factors in fetal life3-8.
The purpose of this intervention study was to evaluate the impact of maternal nutrition during pregnancy on infant blood pressure.
In Turku (Finland), 256 pregnant women were randomized into one control or one of two intervention study groups9 with the aim to modify their dietary fatty acid composition in conjunction with a balanced diet, using tools such as dietary counselling supported by the provision of appropriate food products. The control group received standard dietary counselling in well-women clinics and a placebo; the two dietary intervention groups (with probiotics or with placebo) received detailed dietary counseling by a dietician aimed at achieving a healthy diet complying with current recommendations10, 11, 12. Each mother-infant group was followed from pregnancy through to infant age 6 months, with specific focus on the infant’s blood pressure.
Food and Nutrient Intake During Pregnancy
The women in the dietary intervention groups consumed significantly less butter but more margarine and vegetable oil during the follow-up compared with the controls. These changes in food intake were reflected in the intake of nutrients: the intakes of monounsaturated and polyunsaturated fatty acids were higher and the intake of saturated fatty acids was lower in the intervention groups than in the control group, both as absolute quantities and as proportions of energy intake,. The intake of protein as a proportion of energy intake and intake of calcium was also lower, whereas the intakes of fiber, vitamin D, vitamin E, and riboflavin were higher in the dietary intervention groups compared with the controls.
Impact of Maternal Dietary Intake During
Pregnancy on Infant Blood Pressure
For an in-depth evaluation of the associations between dietary intakes during pregnancy and infant blood pressure, the mean intakes of energy, foods, and nutrients during pregnancy were divided into quartiles, and their associations with infants’ blood pressure were studied.
Maternal dietary intake demonstrated a statistically significant nonlinear association with infants’ blood pressure. Most associations showed a Ushaped dose dependency; the highest and lowest quartiles of nutrient intakes during pregnancy resulted in higher blood pressure at age 6 months compared with the middle quartiles. Maternal carbohydrate intake during pregnancy had the strongest impact on infant systolic and diastolic blood pressures. The intake of monounsaturated fatty acids also had a significant effect on diastolic blood pressure. In addition, a trend toward a U-shaped relationship between total energy intake and vitamin B12 intake and infant systolic blood pressure was observed, and a similar tendency emerged between maternal fibre intake and infant diastolic blood pressure. A reverse U-shaped trend was observed between maternal fruit intake and infant systolic blood pressure.
Modeling of Infant Blood Pressure by Maternal Nutrition
Infants’ systolic or diastolic blood pressure was not associated with infants’ birth weight or with the duration of gestation. Instead, blood pressure was lower in infants breastfed at 6 months compared with those who were not. Likewise, infant length at 6 months correlated positively with blood pressure. Maternal carbohydrate intake was found to best explain infant blood pressure at age 6 months in the multivariate analyses for systolic pressure and diastolic pressure. The U-shaped doseresponse remained even after this adjustment for breastfeeding and infant length at age 6 months.
Dietary factors affect blood pressure directly through intake of nutrients, including sodium and fat, as well as indirectly by means of weight gain13, 14. A low saturated, high unsaturated fatty acids diet, along with high consumption of fruits and vegetables, is generally considered conducive to reducing the risk of hypertension15. The results of the present study extend these notions into fetal life through maternal nutrition, further supporting the likely impact of unknown dietary compounds for health16. Considering the possibility of programming blood pressure from childhood to adulthood17-20, our findings may suggest a novel opportunity for dietary counseling.
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