“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.