Association between maternal intake of n-6 to n-3 fatty acid ratio during pregnancy and infant neurodevelopment at 6 months of age: results of the MOCEH cohort study.

Key Findings:

There is some evidence that the n-6/n-3 PUFAs is associated with neurodevelopment in infants and in the child’s subsequent cognitive development. The present study aimed to determine the association between dietary intake of LC-PUFAs and their ratios in pregnant Korean women with their infants’ neurodevelopment at 6 months of age. Both the maternal dietary n-6/n-3 PUFAs and LA/ALA during pregnancy were negatively associated with both the MDI and PDI at 6 months of age, but maternal intakes of total n-6, n-3, LA, and ALA were not associated with these development parameters. These results indicate that an adequate and balanced intake of n-6 and n-3 PUFAs, or LA and ALA, from a well-balanced diet, may be more important than the intake of these individual fatty acids, for optimal infant’s neurodevelopment. Recent experimental studies reported that maternal n-6/n-3 PUFAs and LA/ALA imbalances induced impaired neocortical neurogenesis in offspring and anxiety-related behavior in adulthood. A balanced intake of n-6 and n-3 fatty acids has important health benefits, particularly during pregnancy. Here, maternal LC-PUFAs intake, particularly n-6/n-3 PUFAs and LA/ALA, during pregnancy was negatively associated with neurobehavioral outcomes in infants at 6 months of age. Therefore, an adequate and balanced intake of n-6 and n-3 fatty acids or LA and ALA, from a well-balanced diet, should be recommended for pregnant women, to promote optimal infant’s neurodevelopment.

ABSTRACT

Long-chain polyunsaturated fatty acids (LC-PUFAs) are essential for infant neurodevelopment. The nutritional adequacy of dietary LC-PUFAs depends not only on the LC-PUFAs intake but also on the n-6 to n-3 fatty acid ratio (n-6/n-3 PUFAs). This study aimed to identify the association between the maternal dietary n-6/n-3 PUFAs and motor and cognitive development of infants at 6 months of age. We used data from 960 participants in the Mothers and Children’s Environmental Health (MOCEH) study, which is a multi-center prospective cohort study. Dietary intake of pregnant women was assessed by a one-day 24-h recall method. Food consumption of infants was estimated based on the volume of breast milk and weaning foods. The duration of each feed was used to estimate the likely volume of milk consumed. Dietary intake of infants at 6 months was also assessed by a 24-h recall method. Cognitive and motor development of infants at 6 months of age was assessed by the Korean Bayley scales of infant development edition II (BSID-II) including the mental developmental index (MDI) and the psychomotor developmental index (PDI). Maternal intakes of n-6/n-3 PUFAs and linoleic acid (LA)-to-α-linolenic acid (ALA) ratio (LA/ALA) were 9.7 ± 6.3 and 11.12 ± 6.9, respectively. Multiple regression analysis, after adjusting for covariates, showed that n-6/n-3 PUFAs was negatively associated with both the MDI (β = -0.1674, P = 0.0291) and PDI (β = -0.1947, P = 0.0380) at 6 months of age. These inverse associations were also observed between LA/ALA and both the MDI and PDI (MDI; β = -0.1567; P = 0.0310, PDI; β = -0.1855; P = 0.0367). Multiple logistic regression analysis, with the covariates, showed that infants whose mother’s LA/ALA were ranked in the 2^nd, 3^rd, and 4^th quartile were at approximately twice the risk with more than twice the risk of delayed performance on the PDI compared to the lowest quartile (1^st vs. 2^nd; OR = 2.965; 95% CI = 1.376 - 6.390, 1^st vs. 3^rd; OR = 3.047; 95% CI = 1.374 - 6.756 and 1^st vs. 4^th; OR = 2.551; 95% CI = 1.160 - 5.607). Both the maternal dietary n-6/n-3 PUFAs and LA/ALA intake were significantly associated with the mental and psychomotor development of infants at 6 months of age. Thus, maintaining low n-6/n-3 PUFAs and LA/ALA is encouraged for women during pregnancy.