A research team with members from Tufts and Boston Universities published a report linking low zinc levels to higher rates of pneumonia in nursing home patients.
The study, released earlier this fall and led by Dr. Simin Meydani, was conducted at the Jean Mayer Human Nutrition Research Center on Aging (HNRCA), an institution created and supported by a partnership between Tufts and the United States Department of Agriculture. The HNRCA is located on Tufts' Health Sciences campus in Boston.
Between 1998 and 2001, researchers randomly selected residents from 33 Boston area nursing homes and gave them either multivitamin supplements or a placebo every day for a year. They then tested the residents' blood levels, looking for various vitamins and minerals.
While the team was initially looking for a correlation between vitamin E and fewer upper respiratory tract infections such as pneumonia, the results were startling: Zinc proved to be more effective at preventing the infections than vitamin E.
And the effects of zinc did not stop there. Residents with normal levels of zinc needed less prescriptions for new antibiotics, did not have to use them for as long, and had a lower mortality rate from all causes compared to those who had deficient zinc levels.
"In a way it was a surprise," said Dr. David Klurfeld, the national project leader for human nutrition at the Department of Agriculture.
Another unexpected result of the study was that a significant amount of nursing home residents did not get the required daily amount of zinc.
"My colleagues and I were surprised to find that 30 percent of the elderly in the Boston area have low ... zinc levels," Meydani said in an e-mail. "This is what you would expect to see in countries where malnutrition is prevalent."
Zinc can be found in foods such as shellfish, nuts and some types of meat. While it may not be difficult for a young or middle-aged person to eat these foods, they may be too hard, stringy or tough for an elderly person to chew.
Meydani said that the results, while unexpected, make sense. "Zinc is essential for the function of the immune system, and zinc deficiency impairs the immune response," she said. "Immune response is of course important for resistance to pneumonia."
The study is expected to have a major impact on health care for the elderly.
Susan Bowerman, the assistant director of the UCLA Center for Human Nutrition and a writer for the Los Angeles Times, said the study highlights the necessity of encouraging the elderly to use dietary supplements.
"I think it brings to light the fact that older people - who have [a] marginal intake of many nutrients, often due to lack of finances, poor appetite, ... etc. - could benefit from [that]," Bowerman said in an e-mail.
She added that few people realize the importance of zinc and its effects on the immune system, and as a result, do not consume enough each day.
According to Meydani, the study needs to be conducted once more with zinc as the primary focus before the results can be accepted.
"We hope that the strong association we have observed in this study will convince the funding agencies to provide support for [an additional study]," she said.
Should the new study confirm a link between zinc and pneumonia, Meydani believes it would lead to a change in the daily zinc consumption recommended for the elderly.
"This would be a very inexpensive way to prevent the elderly from getting pneumonia and could save millions of dollars in health care costs," she said.
The study done by Meydani and her team is just one of many conducted at the HNRCA over the course of its 30-year association with the Department of Agriculture.
According to the HNRCA's Web site, eight studies are currently underway, three of which are vitamin-related.
According to Klurfeld, Tufts has been very supportive of the HNRCA. "There is no better place in the world for a nutrition and aging center," he said.
Klurfeld also commended Meydani, who received a Ph.D. in nutrition from Iowa State University and a DVM from the University of Tehran, Iran. "She's one of the leading researchers in the world on diet and immunity, and we're very happy to have her," he said.
Meydani, in addition to her research, is an immunology professor at the Sackler School of Graduate Biomedical Sciences. She is also the associate director of the HRNCA.
Other members of Meydani's team included Dr. Gerard Dallal, Paul Jacques, Junaidah Barnett, David Hamer and Basil Fine.
