How long you breastfeed your child could dictate how bright he will be in later life, claim researchers from Denmark.
A number of studies have suggested a possible link between breastfeeding and cognitive and intellectual development in early and middle childhood. However, few examined the association in older children and adolescents, and those that did have been called into question.
The Danish investigators used two separate groups of young adults assessed by two different intelligence tests - to make sure their results were valid.
Indeed, their results confirmed a strong link between duration of breastfeeding and intellectual performance as adults.
'The nutrients in breast milk, behavioural factors, and factors associated with the choice of feeding method may all contribute to the positive association,' say the authors (JAMA, 2002; 287: 2365-71).