Effects of prolonged calorie restriction on inflammation and immune function: a randomized controlled trial in non‐obese humans (40.4)

Calorie restriction (CR) is shown to improve inflammatory and immune responses and extend life in animals; however, the effect of prolonged CR in humans has not been studied. CALERIE is a multi‐center randomized controlled trial, which evaluated the impact of 2 y of 25% CR on key biological functions. As part of the CALERIE we determined the impact of CR on immune and INFL markers of 218 healthy adults aged 21‐50 y with BMI of 22‐ 29 kg/m 2 . Participants were allocated in a 2:1 ratio to 25% CR or ad‐libitum (AL) diets. Serum markers of inflammation (CRP, TNFα, IL‐6, IL‐8, ICAM‐1, MCP‐1), as well as WBC counts (total and subset), and antibody response to hepatitis A, tetanus/diphtheria, and pneumococcal vaccines were measured at baseline and after 1 and 2 y of CR. CR significantly reduced CRP and TNFα relative to AL at 24 mo. The estimated change from baseline to 24 mo was ‐0.65 vs. ‐0.023 μg/mL for CRP (p=0.012 for group effect), and ‐0.77 vs. ‐0.38 pg/mL for TNFα (p=0.025 for group effect). No significant effect was observed for other inflammatory markers. In addition, CR was associated with a small, but significantly lower number of WBC, lymphocytes, and monocytes. There was no significant effect of CR on DTH or response to vaccines. These results suggest that 2 y of CR may reduce key indicators of inflammation, but has only a small or negligible impact on cell mediated immunity. Grant Funding Source : Supported by NIH U01AG022132, U01AG020478, U01AG020487, and U01AG020480.