Third Trimester Vegetable Intake May Boost Kids' Cognition

Medscape

09-06-2025

Children whose mothers consumed greater amounts of polyphenols in the last trimester of pregnancy scored significantly higher on several cognitive measures at 8 years of age than children of mothers with lower polyphenol intakes in the last trimester, according to data from a new study presented at the annual meeting of the American Society for Nutrition.
'Polyphenols are nonnutritive phytochemicals present in fruits and vegetables and are linked to improved cognitive health in adults,' said presenting author Chelsey Fiecke, PhD, a postdoctoral fellow at Arkansas Children's Nutrition Center and University of Arkansas for Medical Sciences, Little Rock, Arkansas, in an interview.
Chelsey Fiecke, PhD
Although prenatal fruit and vegetable intake has been linked to improvements in children's cognitive development, studies are needed to target critical prenatal and postnatal polyphenol exposure windows, said Fiecke.
Notably, data on associations between prenatal polyphenol intake at different points during pregnancy and cognitive development in school-age children are lacking, the researchers noted.
To examine these associations, Fiecke and colleagues enrolled 124 mother-child pairs at a single center. Participants were enrolled during pregnancy, and follow-up visits occurred when the children were 5 and 8 years old.
Prenatal polyphenol intake was estimated on the basis of 3-day food records. Cognitive development for 62 children was based on the Wechsler Abbreviated Scale of Intelligence-II at 8 years of age. For 85 children, the researchers used the Wide Range Achievement Test 4 to assess reading, spelling, and math skills at ages 5 and 8 years.
The researchers used linear mixed models for data available at both follow-up visits and generalized models when data were limited. They controlled for factors including maternal IQ, gestational age, and prenatal consumption of carotenoids, docosahexaenoic acid, choline, and vitamin A.
Overall, the participants' average prenatal polyphenol intake was 815 mg/d. In the first trimester, greater maternal polyphenol intake was negatively associated with verbal IQ, perceptual reasoning IQ, and full-scale IQ ( P = .057, P = .020, and P = .011, respectively) in their children.
Polyphenol intake during the second trimester was not significantly associated with any cognitive outcomes of offspring. However, during the third trimester, maternal polyphenol intake was positively associated with children's scores for reading, spelling, and verbal IQ ( P = .035, P = .052, and P = .067, respectively).
Greater polyphenol intake was also associated with higher scores on the Similarities subtest (a verbal reasoning component of verbal IQ; P = .029).
The suggestion of critical exposure windows for prenatal polyphenol intakes for optimal cognitive development was an especially interesting finding, Fiecke told Medscape Medical News . 'It suggests that polyphenols may have similar functionality to other nutrients that play roles in brain and cognitive development, such as docosahexaenoic,' she said.
The results of the study need to be expanded to more diverse longitudinal cohorts, said Fiecke. In addition, research is needed to identify the extent of in utero transfer of polyphenols and to better understand how polyphenols might support optimal cognitive development during other critical exposure windows, such as the early postnatal period, she said.
One Piece of the Food Puzzle
'It is well known that maternal nutrition during pregnancy has effects on both the mother and unborn child, with results implicating nutrition in overall neonatal health and newborn weight,' said Catherine Haut, DNP, CPNP-AC/PC, in an interview.
The current study highlights one substance found in fruits and vegetables, polyphenol, which is also found in other substances consumed by pregnant women, notably coffee, tea, and chocolate, said Haut, director of Nursing Research and Evidence Based Practice at Nemours Children's Health, Wilmington, Delaware Valley, who was not involved in the study.
The effect of healthy nutrition in the last trimester of pregnancy on infant brain development and subsequent childhood cognition is not unexpected, Haut told Medscape Medical News . 'However, it would be of interest to follow children's nutritional intake of polyphenol over the same period with and without considering maternal intake,' she said. 'Maternal nutrition will most likely reflect what is then fed to their children,' she added.
Takeaways and Research Gaps
The study findings support the current daily nutrition guidelines for all age groups to include appropriate portions of fruits and vegetables, said Haut.
The current study was limited by the focus on a single state and location, despite the longitudinal results, and the sample size was small relative to the number of children in the United States, she noted.
Looking ahead to a future study, 'it would be helpful to include more diverse populations and to inquire about daily fruit and vegetable intake in children starting at 6 months of age for infants, when solid food is typically introduced,' Haut added.