Effect of Modest Caloric Restriction on Oxidative Stress in Women, a Randomized Trial

OBJECTIVES It is not established to what extent caloric intake must be reduced to lower oxidative stress in humans. The aim of this study was to determine the effect of short-term, moderate caloric restriction on markers of oxidative stress and inflammation in overweight and obese premenopausal women. MATERIALS/METHODS Randomized trial comparison of 25% caloric restriction (CR) or control diet in 40 overweight or obese women (body mass index 32±5.8 kg/m(2)) observed for 28 days and followed for the next 90 days. Weight, anthropometry, validated markers of oxidative stress (F(2)-isoprostane) and inflammation (C-reactive protein), adipokines, hormones, lipids, interleukins, and blood pressure were assessed at baseline, during the intervention, and at follow-up. RESULTS Baseline median F(2)-isoprostane concentration (57.0, IQR = 40.5-79.5) in the CR group was 1.75-fold above average range for normal weight women (32.5 pg/ml). After starting of the caloric restriction diet, F(2)-isoprostane levels fell rapidly in the CR group, reaching statistical difference from the control group by day 5 (median 33.5, IQR = 26.0-48.0, P<0.001) and remained suppressed while continuing on the caloric restriction diet. Three months after resuming a habitual diet, concentrations of F(2)-isoprostane returned to baseline elevated levels in ∼80% of the women. CONCLUSIONS Oxidative stress can be rapidly reduced and sustained through a modest reduction in caloric intake suggesting potential health benefits in overweight and obese women. TRIAL REGISTRATION Clinicaltrials.gov NCT00808275.