Zinc Salts in Treating Gastric Reflux

Frank Han | frank.han@yale.edu December 1, 2010

Zinc Salts in Treating Gastric Reflux

Groundbreaking research at the Yale School of Medicine has shown that zinc salts can be used to quickly and effectively treat painful gastric acid-reflux diseases. Published in the American Journal of Gastroenterology, this study was conducted by John Geibel, Professor of Surgery and of Cellular and Molecular Physiology. By collecting data of whole stomach acid secretion in rats as well as gastric pH measurements of healthy human volunteers, Geibel and his lab were able to show that the administration of zinc tablets can quickly raise intragastric pH levels from 1 to >3, presenting a potentially novel therapy to inhibit excess gastric acid secretion.

Gastric acid-related diseases have a lifetime prevalence of 25% in the United States and affects over 5% of the world’s population. Normally gastric acid, which is secreted by parietal cells lining the stomach, prevents bacterial overgrowth and helps digestion by facilitating the absorption of iron, calcium, and vitamin B12. However, if the complex sets of regulatory feedback loops that control the secretion of gastric acid are disrupted, then uncontrolled release of gastric acid can result in painful acid reflux, gastric acid-related diseases, and even death.

For the past thirty years, the standard treatment for these gastric acid-related diseases has been the administration of proton pump inhibitors (PPI), such as omeprazole. This class of drug works by directly blocking the H+/K+ ATPase pumps of the parietal cells, thus blocking acid secretion. However, these drugs have been shown to have various negative attributes and side effects. Not only do they potentially interfere with cholesterol-lowering statin drugs but also often take up to 24-36 hours to fully relieve the symptoms. Furthermore, new studies have linked the long-term administration of PPIs with increased risk of hip damage. Geibel stated that since over 60% of patients using PPIs are unsatisfied, his lab tried to find a natural product that could treat these gastric acid-related diseases through alternative pathways.

To address these problems of delayed delivery time and harmful long-term side effects, Geibel’s lab searched for an organic product that could offer immediate relief for acid reflux. “Zinc salts, which are an essential component of our diet that do not need to be metabolized like PPIs do, were the perfect candidate,” said Geibel. Because Zn2+ can ride various ion transports on the cell membranes, these salts are proposed to flood the transporters and create a positive ion flux that cancels out the electrochemical gradient responsible for powering the H+/K+ ATPase, thereby stopping acid secretion in a matter of minutes.

To test this hypothesis, intracellular pH was measured in both human and rat gastric glands following the administration of secretagogues. Indeed, the rate of acid secretion was decreased by 90% from the parietal cells. In another set of studies, whole stomach acid secretion was monitored in rats to show that the zinc salts were effective without having to pass through the bloodstream. A final clinical study monitored the gastric pH of healthy human volunteers while they received a placebo, zinc salt, or a zinc salt and proton pump inhibitor (PPI). Not only were no side effects reported, but also the zinc salts were shown to work for up to four hours in keeping gastric acidity levels down.

This potential treatment for gastric acid-related diseases using zinc salts still needs to undergo Phase II and III of drug testing before it can be made publicly available. Dr. Geibel is nevertheless hopeful that at least a chewable tablet containing zinc will soon be provided over the counter to supplement PPIs.