Infants with a genetic predisposition to autism can be protected from the disorder through breastfeeding, a new study suggests.
Researchers led by Kathleen Krol of the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, focused on the relationship between breastfeeding, genes and the ability to perceive emotions.
Krol and her team studied 98 infants, all of them seven months old and half of them with two copies of a "risk" variant of the gene CD38, to determine what effect breast-feeding has on babies' perception of emotions.
Recognizing other people's emotions is a key social skill that depends a great deal on information obtained from the area around the eyes of the other individual.
Diminished attention to the other person's eyes is associated with autism-spectrum disorders.
The study, published in the Proceedings of the National Academy of Sciences
, showed that babies who were breast-fed longer spent more time looking at images of "happy" eyes and shied away from "angry" eyes.
Matching this data with the children's genotype, researchers found that the effect of breast-feeding on visual preferences was significant only in the babies who carried the risk gene variation.
The study concluded that breast-feeding is associated with an enhanced sensitivity to emotions in babies, but the authors and other experts stressed that there is no evidence yet that breast-feeding ultimately affects a child's odds of developing autism or that it lessens the severity of autism symptoms.
Scientists from the Singapore National University and the University of Virginia participated in the research.