Low Zinc Meant Higher Mortality In Recent Study

Zinc, an essential element, exists in nearly every cell of the body and is critical to proper immune function. The importance of its role in providing immune support is not yet fully understood, though a new observational study sheds more light on its significance, especially in the elderly.

The recent study assessed the relationship of zinc to health in 578 residents, mean age 84, across 33 nursing homes in Boston. Compared with residents who had low zinc levels, people with normal levels had fewer cases of pneumonia, required fewer antibiotic prescriptions for it, and when they did get pneumonia, they had it for fewer days. Additionally, patients with normal zinc levels had a 39 percent lower all-cause mortality rate than those with low zinc levels.

You might think an obvious solution would be to give zinc supplements to everyone with low serum zinc levels. But it’s not really so simple, explains Simin N. Meydani, DVM, PhD, of the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston, one of the study authors. Key questions need to be answered first, Meydani told me. First, she says, there is the need to explore what’s an appropriate level of zinc for the elderly. Excess zinc disrupts the balance of other minerals including copper and iron and, ironically, it also may have an adverse reaction — weakening the immune response in some people. As with almost all natural and synthetic compounds, there are optimal individual doses. Meydani says that Tufts researchers are now planning a study of nursing home residents to investigate what serum levels of zinc are most beneficial.

In the meantime, though, there is enough evidence from this and previous studies to underscore the importance of maintaining adequate zinc levels. You can obtain zinc from dietary sources, in particular oysters, as well as red meat, poultry, beans and dairy. However, some medications such as antacids interfere with zinc metabolism, as do certain infections or chronic inflammation so, as always, consult your physician.