An observational study funded by the National Institute of Aging and the Agricultural Research Service (ARS) found a large percentage of nursing home residents have a low zinc levels (in their blood). The researchers determined that residents with normal blood zinc levels had a 50 percent reduction in the incidence of pneumonia, compared to those who were deficient.
Simin Nikbin Meydani, the director of the Nutritional Immunology Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Boston, Massachusetts, led the study. ARS is the chief intramural scientific research agency of USDA.
HNRCA researchers have conducted other studies on these same nursing home residents, comprised of approximately 600 senior residing in 33 Boston area nursing homes. Their preceding research evaluated their immune response and respiratory infection rates, comparing those who consumed 200 international units (IU) of vitamin E daily for one year. They found the residents receiving vitamin E were 20 percent less likely to get upper respiratory infections, such as colds, compared to those who didn’t receive it and took a placebo instead.
The secondary analysis of data from that study found a very high percentage of the nursing home residents had very residents had low blood zinc concentrations at baseline and after one year of follow-up. During the trial, everyone was given supplements providing them with half of the recommended dietary allowance of essential vitamins and minerals, including zinc.
Those with normal zinc status were not only less likely to develop pneumonia, they also had fewer new prescriptions for antibiotics, a shorter duration of pneumonia, and fewer days of antibiotic use compared with residents who had low zinc levels. In addition, death occurred less often in the participants with normal blood zinc levels.
The study suggests that supplementation of zinc-deficient elderly may result in reduced risk of pneumonia. The authors recommend that additional controlled clinical trials are needed to test efficacy of zinc supplementation as a low-cost intervention to reduce and prevent death caused by pneumonia among at risk groups, such as nursing home residents with low zinc levels.
American Journal of Clinical Nutrition