Diarrhoea 'stunts mental ability'

By Richard Black
BBC Science Correspondent

The research took place in a shanty town

Repeated bouts of diarrhoea in infancy significantly impairs mental performance later in life, researchers have found.

A team from the University of Virginia followed hundreds of children in a Brazilian shanty town for 14 years.

Those afflicted by diarrhoea showed signs of stunted mental development by the age of 10.

The findings were announced at a meeting of the American Society for Tropical Medicine and Hygiene.

It is well-known that frequent diarrhoea affects growth and physical fitness - but the link with mental performance is not so established.

Lead researcher Dr Richard Guerrant said: "Children are experiencing as many as five, six, eight or more dehydrating, malnourishing diarrhoeal illnesses.

"And the best single predictor of how a child is doing in the third grade in school is how much diarrhoea they had during their first two years of life."

Why diarrhoea has this effect isn't clear but Dr Guerrant believes the childrens' bodies aren't absorbing certain nutrients vital to brain development while they are ill with diarrhoea.

What these nutrients might be and whether food supplementation could help are subjects for ongoing research.

But certainly it is a serious issue and not only for individual children.

Diarrhoeal disease in infancy can reduce people's economic productivity as adults by more than 10%.