Children who are breastfed for longer have better receptive language at the age of three and are more intelligent by the age of seven, a new study indicates.

While breastfeeding has been linked to numerous health benefits in children, including a reduced risk of asthma, diabetes and obesity, less is known about its potential advantages when it comes to cognitive development.

US scientists decided to investigate this further. They looked at the link between breastfeeding and cognition in children aged three and seven. When it came to breastfeeding, the duration was taken into account, as was exclusivity, i.e. was the child fed just breast milk or a combination of breast and formula milk.

The study found that at the age of three, those who had been breastfed for longer had better receptive language. This refers to the comprehension of language - listening and understanding what is being said to you.

It also found that children who were breastfed for longer displayed better verbal and non-verbal intelligence at the age of seven.

"In summary, our results support a causal relationship of breastfeeding in infancy with receptive language at age three and with verbal and non-verbal IQ at school age.

" These findings support national and international recommendations to promote exclusive breastfeeding through age six months and continuation of breastfeeding through at least age one year," the team from Boston Children's Hospital said.

Details of these findings are published in the journal, JAMA Pediatrics.