Low energy and carbohydrate intake associated with higher total antioxidant capacity in apparently healthy adults

The aim of this study was to investigate the associations between plasma total antioxidant capacity (TAC) and anthropometric, biochemical, clinical, and dietary measurements in young and apparently healthy individuals.

We evaluated 156 individuals (91 women and 65 men; ages 23.1 ± 3.5 y; body mass index 22 ± 2.9 kg/m(2)) for anthropometrics, biochemical markers, clinical, dietary, and some components of the antioxidant defense system, including the plasma TAC. Statistical analyses were performed to detect differences between individuals with TAC higher and lower than the mean value and to screen the associations between TAC and variables of interest. A linear regression model was fitted to identify TAC predictors.

Daily caloric intake and macronutrient consumption were lower in individuals who exhibited the highest TAC values (P < 0.05). Linear regression analysis showed that daily calories and carbohydrate intake was a possible negative TAC predictor (P < 0.05). Nevertheless, there was no difference in the values of oxidized low-density lipoprotein in the individuals separated by means of TAC. In contrast, individuals whose plasma TAC values were above the mean showed higher low-density lipoprotein cholesterol concentrations, total cholesterol/high-density lipoprotein cholesterol values, and selenium in nails (P < 0.05).

In physiological conditions, the caloric intake level seems to be an important factor to act in the modulation of plasma TAC, before establishing anthropometric impairments of body or metabolic composition, or both. Additionally, the plasma TAC increase may be able to act as a compensatory mechanism.