Meta-analysis supports zinc for childhood diarrhoea

Zinc supplements were calculated to reduce the duration of diarrhoea by about 15 per cent, and the probability of diarrhoea by about 18 per cent, reports the meta-analysis in the journal Pediatrics​. "Zinc supplementation reduces the duration and severity of acute and persistent diarrhoea,"​ wrote lead author Marek Lukacik from the Medical College of Georgia. "However, the mechanisms by which zinc exerts its anti-diarrhoeal effect have not been fully elucidated." ​ Diarrhoea is a common condition that causes an average of 2.4 million doctor's visits in the US each year. Children younger than the age of five and the elderly can develop severe health problems if their condition leads to dehydration. Lukacik, in collaboration with researchers from Wayne State University School of Medicine and Wayne State University in Detroit, identified 16 studies relating to acute diarrhoea, containing 15,231 children, and six studies of persistent diarrhoea, containing 2,968 children. The researchers only considered randomised, controlled trials that compared oral zinc supplements with placebo. Oral zinc supplements were associated with a 15.0 and 15.5 per cent reduction in the duration of acute and persistent diarrhoea, respectively, and a 17.9 and 18.0 per cent reduction in the probability of diarrhoea, respectively. Furthermore, zinc supplements were calculated to reduce the average stool frequency by 18.8 and 12.5 per cent for acute and persistent diarrhoea, respectively. However, the researcher noted that supplementation with zinc was associated with vomiting, with 11 acute diarrhoea trials and four persistent diarrhoea trials reporting an increase after supplementation, compared to placebo. When the zinc was supplemented in the zinc gluconate form the vomiting was more frequent than when the element was consumed in the sulphate or acetate forms, added Lukacik and co-workers. "On the basis of these findings, which now add to the large body of previously published clinical data and update previous meta-analyses and systematic reviews, zinc therapy is useful for treating both acute and persistent diarrhoea and for their prophylaxis,"​ concluded the researchers. Zinc is one of the most plentiful trace elements in the body, second only to iron. It mediates many physiological functions and is believed to be essential for maintaining a healthy immune system. Nutrition and diarrhoea ​ Nutritional solutions to infant diarrhoea have received increasing research. Recently, supplements of Lactobacillus rhamnosus​ GG probiotic bacteria were reported to protect against gastro-intestinal infection and diarrhoea in infants. The study, published in the open access journal BMC Microbiology, was conducted in animals and showed that 59 per cent of animal subjects did not develop rotaviral diarrhoea when the probiotic was administered before infection with rotavirus. In addition, researchers from Taiwan's China Medical University reported that the popular spice ginger has potential as a herbal supplement against bacteria-induced diarrhoea. The researchers considered the effects of ginger and its bioactive components for their ability to inhibit the binding of a toxin from the bacteria E. coli (heat-labile enterotoxin, LT) to specific receptors on cells in a mouse intestine (GM1 receptors) that initiate a cascade of events resulting in diarrhoea (Journal of Agricultural and Food Chemistry​, doi: 10.1021/jf071460f). Source: Pediatrics​ February 2008, Volume 121, Number 2, Pages 326-336, doi:10.1542/peds.2007-0921 "A Meta-analysis of the Effects of Oral Zinc in the Treatment of Acute and Persistent Diarrhea" ​Authors: M. Lukacik, R.L. Thomas, J.V. Aranda