Green vegetables can give essential iron to a child

The researchers tracked the progress of children from Lima in Peru, from birth up to the age of nine.

They found that by age nine children with severely stunted growth as two-year-olds scored 10 points lower in mental ability tests than their peers.

Monitored

Lead researcher Douglas Berkman said: "(This) indicates that the detrimental effects of malnutrition linger through childhood."

Some 33% of children in developing countries suffer from moderate or severe growth problems, rising to more than 50% in the lesser-developed countries.

Dr Berkman, a medical student at the University of Medicine and Dentistry of New Jersey, conducted the research while studying for his MA at the John Hopkins Bloomberg School of Public Health.

His team initially used data on 239 children from birth to age two from an earlier nutritional study conducted from 1989 to 1991.

This monitored children for growth development and the number of times they had a diarrhoea-related disease or parasite infection.

Dr Berkman and his colleagues, caught up on the progress of 143 (69%) of the original participants in 1999 - one in three of these were stunted during the first two years of life.

The children, now aged nine, were then tested for intelligence.

They were examined using a well-known test for measuring cognitive ability called the Wechsler intelligence scale for children revised (WISC-R)

"Malnutrition is potentially a risk for children anywhere including the UK

Dr Frankie Robinson, BNF

They also looked closely at diarrhoea - both a cause and an effect of malnutrition.

Diarrhoea is triggered by the presence of Giardia lambia bug leading to an intestinal disease.

Early intervention

Children infected with the bug, one or more times a year, scored four points less on the intelligence test than those who had one episode or less of the infection.

The tests were adjusted for socio-economic status and schooling and the researchers warn it would be a mistake to attribute all lack of intelligence in children to growth defects.

But they did recommend early intervention to prevent the effects of stunted growth.

Researcher Robert Gilman, said: "There is a high prevalence of stunted growth in children living in less developed countries.

"Our results can be used in designing intervention programmes seeking to prevent the adverse effects of stunting later in life."

And they say the study emphasises the importance of nutrition among children under three.

'Risk'

In a comment accompanying the article, which appears in Friday's edition of The Lancet, Sally Grantham McGregor from the Institute for Child Health, London, UK, said "urgent attention" should be given to the needs of children in developing countries.

Dr Frankie Robinson, of the British Nutrition Association (BNF), said malnutrition among children is not commonplace in the UK but that should not provoke complacency.

"Malnutrition is potentially a risk for children anywhere including the UK.

"In this country it can affect children in families on a low income."

The lack of Omega 3 fatty acids - found particularly in oily fish and breast milk - can account for a lack of nutrition leading to lower mental capacity, she added.

She urged parents with any concerns about feeding infants to seek advice from their health visited or contact a state registered dietician if there are particular problems.

Lack of iron - found in red meat, breakfast cereals and green leafy vegetables - can also lead to malnutrition problems.