WEDNESDAY, Jan. 12, 2005 (HealthDayNews) -- Zinc supplements may help prevent oral and esophageal cancers in people at high risk for such cancers due to zinc deficiency, says a study by researchers at Thomas Jefferson University in Philadelphia.
They found that giving zinc orally to zinc-deficient rats reversed the development of precancerous conditions in the esophagus and on the tongue, and also reversed high expression of the enzyme cox-2. The study results suggest that zinc supplements may help prevent oral and esophageal cancers.
It was already known that a rise in the expression of cox-2 is connected with oral and esophageal cancers, which are associated with a lack of zinc in the diet. Zinc deficiency is especially prevalent in developing countries.
It's estimated that up to 2 billion people in developing nations are zinc-deficient, compared to up to 10 percent of Americans. Red meat and seafood provide the majority of zinc in the diet.
"Zinc treatment restores many systems affected by the lack of zinc. Zinc deficiency upregulates cox-2. Zinc replenishment restores it to near normal levels," study author Louise Fong, an assistant professor of microbiology and immunology, said in a prepared statement.
The study is published in the current issue of the Journal of the National Cancer Institute.
The U.S. National Library of Medicine has more about the importance of dietary zinc.