Flinders University gastroenterologist Professor Graeme Young is leading a new global project to determine the best way to use zinc – and increase its effectiveness – in the fight against childhood deaths from diarrhoea.
The University has received a $1.5 million grant from the Bill & Melinda Gates Foundation to find the optimum zinc strategy to alleviate diarrhoea and malnutrition in developing countries, and to test Professor Young’s theory that a fibre called resistant starch increases zinc absorption in the body.
Diarrhoea is the world’s second biggest killer of children under five, causing more deaths than measles, HIV/AIDS and malaria combined in this group. It is responsible for the death of about 800,000 children every year and leads to malnutrition in millions of others.
Acute attacks of diarrhoea occur as a result of increased fluid secretion in the intestine, however, Professor Young said zinc therapy “plugs” the leaky intestine common in children in the developing world by strengthening “intercellular junctions” and improving immunity. Zinc also acts to block the secretory process causing the diarrhoea.
While zinc is currently recommended as a medical therapy for an acute attack of diarrhoea, Professor Young said the challenge facing the team he leads – including world experts based in North America, Asia, Africa and Europe – was not just to further improve the medical therapy but to determine how a public health strategy incorporating resistant starch in the diet might prevent diarrhoea from the outset.
“Zinc tablets are currently given in response to an acute attack of diarrhoea but only a minority follow the recommended course of tablets and there may be other complementary ways to ensure we better correct nutritional deficits in zinc and so better deal with the problem,” Professor Young said.
“There needs to be more research to see how these different approaches to improving zinc status of vulnerable children should be implemented as part of a global health strategy to keep them healthy and prevent acute attacks of diarrhoea,” he said.
“Many children in developing countries already have marginal zinc deficiency so they’re more susceptible to repeated attacks of diarrhoea, which in turn tips them over into an acute deficiency state, putting them at risk of infection, malnutrition, poor mental development and stunted growth. Therefore further improving zinc status could be expected to improve these outcomes.”
As part of the study, Professor Young is hosting an international conference from September 10-12 in Seattle where more than 30 world experts will examine in detail the role of zinc in treating diarrhoea.
In the second phase of the project, which has just commenced, Professor Young’s colleagues from Christian Medical College in Vellore and Washington University in St Louis are studying different types of resistant starch in India and Malawi to see which most effectively increases zinc “bioavailability”, or absorption.
“Resistant starch behaves like dietary fibre, meaning it ferments and releases short chain fatty acids which are very important for the health of the bowel,” Professor Young said.
“We now have evidence that these chemical changes lead to improved solubility of zinc in animals so the next step is to work out whether the same applies for humans.
“However this is a highly complex task because unlike most other mineral and vitamin nutrients, it is difficult to determine zinc status in the body. Marginal zinc deficiency can go undetected without there being any obvious indicators, yet it renders children vulnerable to many infections.
“If we can work out how to increase zinc absorption, and the best way to deliver it, then we could very well give millions of children a greater chance at life.”