Breastfeeding for longer can boost children's IQ and language ability, new research has suggested.
Seven-year-olds who were breastfed until their first birthday were likely to score four points higher on a verbal IQ test than those who had been bottle-fed as babies, according to a US study published in JAMA Pediatrics.
Scientists uncovered a clear link between the duration of breastfeeding and intelligence test performance at age seven.
Verbal intelligence scores increased by 0.35 points for every extra month of breastfeeding, while non-verbal IQ scores rose by 0.29 points for every additional month a child was breastfed.
The improvement was most noticeable among children who were exclusively breastfed, who boosted their verbal IQ scores by nearly a point per month.
Seven-year-olds who were exclusively breastfed for the first six months after birth had an almost five point advantage over those who were bottle-fed.
The scientists, led by Dr Mandy Belfort of Boston Children's Hospital, wrote: "Our results support a causal relationship of breasfeeding 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."
Copyright Press Association 2013