Zinc deficiency a global concern

Two billion people around the world have diets deficient in zinc – and studies at Oregon State University and elsewhere are raising concerns about the health implications this holds for infectious disease, immune function, DNA damage and cancer.

One new study has found DNA damage in humans caused by only minor zinc deficiency.

Zinc deficiency is quite common in the developing world. Even in the United States, about 12 percent of the population is probably at risk for zinc deficiency, and perhaps as many as 40 percent of the elderly, due to inadequate dietary intake and less absorption of this essential nutrient, experts say. Many or most people have never been tested for zinc status.

Studies have shown that zinc is essential to protecting against oxidative stress and helping DNA repair – meaning that in the face of zinc deficiency, the body's ability to repair genetic damage may be decreasing even as the amount of damage is going up.

Two studies recently published, in the Journal of Nutrition and the American Journal of Clinical Nutrition, found significant levels of DNA damage both with laboratory animals and in apparently healthy men who have low zinc intake. Zinc depletion caused strands of their DNA to break, and 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," Ho said. "An inadequate level of zinc intake clearly has consequences for cellular health."

Many zinc studies, Ho said, have focused on prostate cancer – the second leading cause of cancer deaths in American men – because the prostate gland has one of the highest concentrations of zinc in the body, for reasons that are not clearly known.

When prostate glands become cancerous, their level of zinc drops precipitously, and some studies have suggested that increasing zinc in the prostate may at least help prevent prostate cancer and could potentially be a therapeutic strategy. There are concerns about the relationship of zinc intake to esophageal, breast, and head and neck cancers. And the reduced zinc status that occurs with aging may also contribute to a higher incidence of infection and autoimmune diseases, researchers said in one study in the Journal of Nutrition.

Zinc is naturally found associated with proteins in such meats as beef and poultry, and in even higher levels in shellfish such as oysters. It's available in plants but poorly absorbed from them, raising additional concerns for vegetarians. And inadequate intake is so prevalent in the elderly, Ho said, that they should usually consider taking a multivitamin to ensure adequate levels.

Steve - we have a very simple way of testing zinc status. Come to our office for a taste test of our zinc sulfate solution. Detecting and addressing zinc deficiency is imperative for overall health, especially for men.