Vitamin C and fibre consumption from fruits and vegetables improves oxidative stress markers in healthy young adults

Abstract

The aim of the present cross-sectional study was to assess the potential relationships between fruit and vegetable (FV) consumption and some oxidative stress markers in young adults, with particular emphasis on fibre and vitamin C intake. The study enrolled 246 healthy subjects (eighty-eight men and 158 women), with a mean age of 22 (SD 3) years and a mean BMI of 21·9 (SD 2·8) kg/m2. Dietary intake, anthropometry, blood pressure, lifestyle features and blood biochemical data were assessed with validated procedures. Those subjects in the highest tertile (T) of FV consumption ($705 g/d) had statistically lower oxidised LDL (ox-LDL) concentrations as well as higher plasma total antioxidant capacity (TAC) and glutathione peroxidase (GPx) activity (P for trend,0·05), after adjusting for sex, age, energy intake, physical activity, smoking, BMI, vitamin supplement use and other confounding factors. Moreover, plasma ox-LDL concentrations showed a decreasing trend and TAC an increasing trend across tertiles of fibre (T3: $14 g/d) and vitamin C (T3: $150 mg/d) from FV intake, while GPx activity was positively associated with vitamin C intake (P for trend,0·05). In conclusion, greater FV consumption was independently associated with reduced ox-LDL as well as increased TAC and GPx activity in healthy young adults, with dietary fibre and vitamin C from FV clearly being implicated in this beneficial relationship.