Some 40% of America's elderly are impacted.

• Position: Zinc Deficiency

Zinc helps control infections by gently tapping the brakes on the immune response in a way that prevents out-of-control inflammation that can be damaging and even deadly, according to research published in the journal Celt Reports. Scientists determined in human cell culture and animal studies that a protein lures zinc into key cells that are first-responders against infection. The zinc then interacts with a process that is vital to the fight against infection and, by doing so, helps balance the immune response.

This study revealed for the first time that zinc homes in on this pathway and helps shut it down, effectively ensuring that the immune response does not spiral out of control. If there is not enough zinc available at the time of infection, the consequences include excessive inflammation.

In this research, zinc's activity was studied in the context of sepsis, a devastating systemic response to infection that is a common cause of death in intensive-care unit patients, but scientists say these findings also might help explain why taking zinc tablets at the start of a common cold appears to help stem the effects of the illness.

"We do believe that, to some extent, these findings are going to be applicable to other important areas of disease beyond sepsis," says Daren...