Efeitos da dieta, atividade física e estresse psicológico nos danos oxidativos de mulheres jovens

Abstract

The consumption of antioxidant-rich foods, especially fruits and vegetables, have been associated with a lower incidence of chronic diseases. However, it is known that diet has a lot of active compounds and none antioxidant compound and/or food alone may reflect the total antioxidant power of diet. Therefore, to estimate the total intake of dietary antioxidants is important to evaluate its beneficial health effects. In this context, the aim of this study was to estimate the dietary total antioxidant capacity (DTAC) and its relationship with the plasmatic total antioxidant capacity (PTAC) and markers of damage to biomolecules in healthy women. It was conducted a study with 141 women aged 18 to 35 years. Smokers and those using continuous medication (except oral contraceptives) and/or antioxidant supplementation were excluded. To determine the DTAC, it was applied a 24-hour recall. The PTAC was determined by commercial kit. Oxidative damage to lipids were evaluated by determination of thiobarbituric acid reactive substances (TBARS) and damage to proteins by quantifying protein carbonyls groups (CP). Comet assay was used to assess DNA damage. Furthermore, we evaluated the intake of nutrients in the diet. Potential confounders factors, such as physical activity and psychological stress, were also evaluated. The DTAC of volunteers ranged from 9.62 to 2226.64 mg VCE/day and the foods that most contributed to increase the DTAC were mate, coffee, tea, orange juice, bananas, apples, beans, grape juice and broccoli. These foods are rich in polyphenols and/ or vitamin C, which were positively correlated with DTAC and the PTAC, showing the importance of these antioxidants in the human diet. It was identified three major nutrient patterns labeled as Antioxidant, B Complex and Protein/Fat. The PTAC of the population ranged from 0.78 at 2.26 mmol Trolox/L and there was a positive correlation between levels of PTAC and DTAC, suggesting that DTAC may be a good tool to assess the antioxidant status of the population. Women who were engaged in physical activity 3 or more times per week had a significantly higher DTAC compared to those who did not exercise. Moreover, the DTAC was negatively associated with levels of oxidative lipid damage and the DNA damage index was positively associated with plasma cortisol levels. The data obtained in this study contribute to a better understanding of the relationship between DTAC and biomarkers of oxidative damage.