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Mothers who followed the Mediterranean diet while pregnant improved their children’s cognitive, social and emotional development at age 2 compared with children whose mothers did not follow the diet, according to a new randomized clinical trial.
“Despite previous evidence suggesting (an) association between adverse lifestyle (patterns) and poorer child neurodevelopment, no previous studies had evaluated whether lifestyle interventions improved neurodevelopment,” said study coauthor Dr. Francesca Crovetto, a postdoctoral researcher at the BCNatal Fetal Medicine Research Center at the Universitat de Barcelona in Spain, via email.
“At year 2 the children’s brains are harvesting some of the benefits that they received in their adequate nutrition during their intrauterine life,” said Dr. Miguel Martínez-González, a professor of preventive medicine and public health at the University of Navarra in Pamplona, Spain, in an email. He was not involved in the study.
“No other dietary model possesses such an impressive accrual of scientific evidence as the traditional Mediterranean diet,” said Martínez-González, who is also an adjunct professor of nutrition at the Harvard T.H. Chan School of Public Health in Boston.
The Mediterranean diet, which features simple, plant-based cooking, has been shown in studies to reduce the risk for diabetes, high cholesterol, dementia, memory loss, depression, stronger bones, a healthier heart and longer life.
Children of mothers who took a stress-reduction class during pregnancy also scored higher in social and emotional well-being as toddlers compared with children of mothers who did not receive the training, according to the study published Tuesday in JAMA Network Open.
“Stress is not just a feeling, it is a feeling that echoes through our endocrine and nervous and immune systems,” said Dr. David Katz, a specialist in preventive and lifestyle medicine who founded the nonprofit True Health Initiative, a global coalition of experts dedicated to evidence-based lifestyle medicine. He was not involved in the study.
“There are changes in hormone levels with stress, and we should not be surprised to learn that variations in maternal hormones have implications for fetal and neonatal development and health,” Katz said.
“I would hope this study gives people a deep appreciation for what an incredible opportunity there is to use lifestyle as medicine during pregnancy to give our newborns the best possible start in life.”
Following the children of prior study
The study followed children born to 1,221 high-risk mothers who were part of The Improving Mothers for a Better Prenatal Care Trial Barcelona, a randomized clinical trial conducted between February 2017 and March 2020. All of the women in the study had been identified as carrying a fetus with a high risk of being born small for their gestational age, a leading cause of infant death.
One group of women was randomized to follow a Mediterranean diet and given free olive oil and walnuts, and met monthly with trained nutritionists who provided recipes, shopping lists and a weekly meal plan.
Another group of high-risk women was assigned to eight weeks of pregnancy yoga, meditation and mindfulness group sessions and home-based interventions, which all focused on the relationship between the mother and the developing baby. A third group of women was given standard prenatal care.
The initial results of the study were published in December 2021. Nearly 22% of women who received only prenatal care gave birth to babies of low weight, the research team found. The number of low-weight births dropped to 15.6% of the women who attended stress-reduction classes and 14% of the women who ate a Mediterranean diet.
Maternal Mediterranean diet nourishes fetus
Approximately two years after the women gave birth, researchers visited 626 children, or representing about half of the original study group, and administered the Bayley Scales of Infant and Toddler Development, a well-known measure of cognitive, social and emotional infant development.
On the cognitive test, there was a 5-point favorable difference between children whose mothers ate a Mediterranean diet and those in the control group who did not, Katz said.
“Overwhelmingly, fetal nutrients are a byproduct of maternal diet,” he added. “Maternal dietary pattern and quality will thus influence fetal exposures to diverse nutrients and will even influence taste preferences early in life.”
Both stress reduction and the Mediterranean diet increased scores of social and emotional development, but only the Mediterranean diet intervention was statistically significant — meaning the outcome was greater than chance.
“For me, the most important result and most generalizable for the population of pregnant women is the improvement in the average overall cognitive composite score in the Mediterranean diet group,” Martínez-González said in an email.
“The first arm (Mediterranean diet) addressed a more physical and direct aspect: the dietary pattern and the supply of interesting nutrients that are known to be beneficial. They are likely to be important for the development of the child’s brain,” he added.
However, there was an improvement in only one of the elements of the cognitive score in the stress-reduction group compared with controls, Martínez-González said.
“The promotion of meditation-mindfulness needs more evidence. It is likely that it may be beneficial, but further studies are needed.”