Australian researchers found that babies mainly breastfed for at least six months went on to score significantly higher in academic tests at the age of ten, especially boys.

Researchers from the Telethon Institute for Child Health Research in Perth, the Curtin Health Renovation Research Institute, Centre for Developmental Health, and the National Drug Research Institute, Curtin University of Technology, also in Perth, published their findings online ahead of print in the journal Pediatrics on 20 December.

Co-author Dr Wendy Oddy, an Associate Professor at the Telethon Institute for Child Health Research, told the media that their study adds to the body of evidence on the benefits of breastfeeding for longer.

She said there are several ways that breastfeeding may boost academic achievement.

“We know that there are vital nutrients in breast milk that support brain development, particularly in terms of long-chain fatty acids,” she said, adding that other studies have already shown breastfeeding accelerates development in boys:”Males are also known to be more vulnerable to adversity during critical periods of development than females, therefore the neuro-protective effect of estrodiols, the female hormones, in breast milk, would have greater benefits for boys,” she explained.

Oddy said evidence also suggests that breastfeeding improves the relationship between mother and child, helping bonding, and also indirectly, cognitive growth.

“A number of studies have found that male babies are more dependent on maternal attention to help develop their cognitive and language skills,” she added.

With their study, Oddy and colleagues were particularly interested in seeing if there were any links between longer periods of breastfeeding and academic outcomes in middle childhood: they hypothesized they would find a t link.

They reviewed the records of the Western Australian Pregnancy Cohort (Raine) Study which has been following the growth and development of over 2,800 children born in Western Australia between 1989 and 1991.

For their analysis they used data on 1,038 eligible boys and girls at age 10 years. This included standardized scores of mathematics, reading, writing and spelling ability.

After adjusting the figures to take out any effects from potential confounders, including maternal factors, family income and “early stimulation at home through reading”, they found that boys were more likely to have attained higher academic scores in mathematics, reading, spelling and writing if they had been mainly breastfed during their first six months of life or longer.

For girls the benefits only showed in reading.

Oddy and colleagues concluded that: “Predominant breastfeeding for 6 months or longer was positively associated with academic achievement in children at 10 years of age.”

“However, the effectiveness of breastfeeding differed according to gender; the benefits were only evident for boys,” they added.