Effect of Fruit and Vegetable Consumption on Immune Function in the Elderly: a Randomised Controlled Trial

The immune system undergoes a range of changes as individuals become elderly. These may manifest as an increasing susceptibility to infection or a tendency to develop autoimmune or malignant disease. Multiple underlying factors contribute to this phenomenon of immunological aging, and in this study the investigators will examine the possibility that inadequate diet may be one such contributing factor. Fruit and vegetable intake, which can be low in the elderly, is associated with reduced chronic disease risk. This proposal will test the hypothesis that increased fruit and vegetable intake may positively affect clinically relevant measures of immune function. One hundred healthy volunteers aged 65-85 years following a low fruit and vegetable diet (<=2 portions/d) will be recruited and randomised to continue following their normal diet, or to consume at least 5 portions of fruit and vegetables daily for 16 weeks. Immune function and biochemical markers of nutritional status will be assessed before and after the intervention period.