NEW YORK, Nov 30 (Reuters Health) - Children under age 5 who have severe diarrhea tend to recover more quickly if given zinc supplements, according to an analysis of studies conducted in developing countries.

The findings, published in the December issue of the American Journal of Clinical Nutrition, may be used to help children in such countries, where diarrhea is a serious health problem and causes millions of deaths each year. Those who survive often suffer from malnutrition.

The results may also apply to any child who experiences severe diarrhea, according to Dr. Robert E. Black, a professor at Johns Hopkins School of Public Health in Baltimore, Maryland, and colleagues.

"Perhaps the use of this effective and inexpensive nutrient supplement would be helpful in efforts to reduce the now common treatment of diarrhea with unnecessary antibiotics and other drugs," the authors suggest.

It is not clear, however, whether such supplements would benefit children in developed countries, who may not have nutrient deficiencies. The children in the study tended to benefit more if they had a zinc deficiency--a condition that can reduce immune function--before treatment started.

"The effect of zinc appears to be by correction of a deficiency in the child because of poor diet," Black told Reuters Health. "Since US children have better zinc intakes than developing country children, they may have less effect. On the other hand, US children often consume less than the recommended amounts of zinc."

The analysis found that doubling the recommended amount of zinc reduced the duration of acute and persistent diarrhea. For children up to 1 year, the recommended dietary allowance (RDA) is 1 milligram (mg) a day and increases to 10 mg a day until children reach adolescence.

According to the report, zinc supplemented children with acute diarrhea--defined as at least three episodes a day--had a 15% lower risk of continuing diarrhea on a given day. Children with persistent diarrhea (lasting at least 7 days) who were supplemented with zinc were 24% less likely to have continuing diarrhea than children who were not supplemented with zinc.

The effect was most pronounced in children with persistent diarrhea who were male and younger than 12 months.

The study included 10 trials conducted in India, Indonesia, Bangladesh, Peru, and Pakistan, which looked at the benefit of zinc supplements in children under 5 years old.

"The results ... indicate that zinc, given during acute or persistent diarrhea, can have substantial clinical benefit and suggest that this adjunctive therapy could reduce the risks of dehydration and death from diarrhea," Black and colleagues write.

"Attention should now focus on the best means of providing zinc during diarrhea or on other ways to improve the zinc (intake) of children in developing countries," the researchers conclude.

(From Reuters)