Nutrients May Enhance Immune Function in the Elderly

Source: Tufts University
February 25, 2002 (Reviewed: February 23, 2004)

Many older adults have to deal with a host of medical issues that put them at risk for malnutrition, a condition that makes them more susceptible to infection. As the number of people over age 65 continues to grow, strategies to reduce this risk are under investigation. A recent article in Clinical Infectious Diseases summarizes current research into nutritional intervention as a way of boosting immune status and preventing infections in the elderly.

Age-related immune dysfunction

Infection is a common problem among older Americans, who are 2 to 10 times more likely to die of infection than younger adults. An age-related decline in immune function probably contributes to that risk, as cells become less able to stimulate an adaptive immune response. Scientists are not yet sure to what degree nutrient deficiencies contribute to that deterioration, in part because there is not yet agreement on what levels of intake will insure adequate absorption. They are, however, taking a close look at how certain nutrients - including vitamin E and trace minerals zinc and selenium - affect infection rate in medically frail older adults.

What may help

Several studies have shown that both zinc and selenium supplements may enhance immune function and reduce the risk of infection. There is some evidence that zinc, in combination with adequate protein and calories, can reduce the incidence of pressure ulcers in institutionalized adults. The author notes that zinc is often the nutrient of choice to promote wound healing, but zinc supplementation may be best suited to those who are malnourished, and likely zinc deficient.

Vitamin E, a potent antioxidant, has also been linked to improved immune response. Few studies, though, have demonstrated the ability of vitamin E to affect clinical end points, such as fewer infections or less antibiotic use, in elderly patients. How much vitamin E is needed to see an effect is still an issue. Researchers have been able to show improved immune response at doses ranging from 200 mg to 800 mg per day. Current U.S. dietary intake recommendations for vitamin E, however, fall far below this level.

Advice to clinicians

The author acknowledges that is it difficult to make specific recommendations concerning the benefit of vitamin and mineral supplements due to the diversity of study findings. He concludes, though, that there are enough data to support the use of a daily multivitamin that includes zinc (20 mg), selenium (100 micrograms), and vitamin E (200 mg). In his opinion, supplements that provide these nutrients may reduce the rate of infections, along with the use of antibiotics, in older adults.

Nutrition supplements serve little purpose unless the underlying cause of malnutrition - be it chronic illness, poorly fitting dentures, depression, or medication-induced anorexia - is identified and treated. A new website sponsored by the American Academy of Family Physicians and the American Dietetic Association addresses this issue (see link "The Nutrition Screening Initiative" below). The site's key document, The Role of Nutrition in Chronic Disease Care (see link below) outlines the nutritional management of chronic illnesses - including cancer, congestive heart failure, pneumonia, and dementia - that can put seniors at risk for malnutrition.

Source

• Nutritional strategies to boost immunity and prevent infection in elderly individuals. KP. High, Clinical Infectious Diseases, 2001, vol. 33, pp. 1892--1900

Related Links
The Role of Nutrition in Chronic Disease Care
Weight Loss a 'Slippery Slope' for Seniors
To quickly access additional accurate information on this and other nutrition-related topics, visit Tufts University's Nutrition Navigator

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