Calorie restriction (CR) enhances T cell mediated immune response in overweight men and women

It is well‐known that dietary energy restriction prolongs life‐span and enhances immune responsiveness in a wide range of laboratory animals. However, information on the applicability of these results to humans is limited. In this study we examined the effects of CR on T cell mediated function in humans. Forty‐six overweight (BMI= 27.9 ± 1.5 Kg/m 2 ) men and women aged 35 to 40 years (35 ± 5) were randomly assigned to a 30% or 10% (control) calorie restricted groups. Delayed type hypersensitivity skin test (DTH), lymphocyte proliferation, prostaglandin E 2 and cytokine productions were determined at baseline and after six months of CR. DTH responses, as well as Con A and PHA stimulated lymphocyte proliferation were significantly increased in both CR groups compared to baseline (p<0.05). However, proliferative response to anti‐CD3 was increased significantly only in the 30% CR group. LPS stimulated PGE 2 production was reduced in both groups, but reached statistical significance only in the 30% CR group (33% decrease, p<0.05). These results, for the first time, show that 6 months of CR in humans improves T cell mediated function. This effect of CR is, at least in part, due to decrease in PGE 2 production, which has been shown to suppress T cell function. Supported by NGA‐3U01‐AG20478 (NIA) and USDA contract #58‐1950‐9‐001.