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.