As many as two billion people around the world have diets deficient in zinc, and experts are concerned about the health implications for the prevention of infectious disease, DNA damage and cancer.
Two studies recently published in the Journal of Nutrition and the American Journal of Clinical Nutrition found significant levels of DNA damage both in laboratory animals and healthy men with low zinc intake.
Zinc depletion caused strands of their DNA to break. Increasing the intake of zinc reversed the damage back to normal levels.
"In one clinical study with men, we were able to see increases in DNA damage from zinc deficiency even before existing tests, like decreased plasma zinc levels, could spot the zinc deficiency," said Oregon State University professor Emily Ho, an expert on dietary zinc, in a statement. "An inadequate level of zinc intake clearly has consequences for cellular health."
While zinc deficiency is common in the developing world, it also affects 12 percent of the population in the United States -- as much as 40 percent of the elderly. This is mostly because of a combination of inadequate dietary intake and reduced absorption.
The problem? Most people have never been tested for their zinc levels, and existing tests to do so are inaccurate at best.
Studies have shown that zinc is essential in protecting against oxidative stress and helping DNA repair. Without it, the body's ability to repair genetic damage decreases.
Zinc also comes into play with prostate cancer, the second leading cause of cancer deaths in American men. For reasons that are not clearly known, the prostate gland has one of the highest concentrations of zinc in the body, and a prostate gland's level of zinc drops drastically when it become cancerous.
Lower levels of zinc have also been tied to the higher incidence of infection among the elderly.
So where can you find zinc? Besides a multivitamin, zinc is naturally found in proteins (beef, poultry, shellfish) and plants, but it's harder to absorb it from the latter, a concern for vegetarians.
On the other hand, don't take more than 50 milligrams a day. Zinc may be an essential micronutrient, but it can interfere with the absorption of other important nutrients if taken in excess.
This post was originally published on Smartplanet.com