Applied nutritional investigationFruit and vegetable intake and related nutrients are associated with oxidative stress markers in middle-aged men

ObjectiveThe aim of this cross-sectional study was to assess the potential relationships between fruit and vegetable (FV) intake and oxidative stress markers in middle-aged men, with an emphasis on vitamin C, fiber, and magnesium content.MethodsThe study was conducted with 296 healthy men, age 50.5 ± 5.0 y, and body mass index (BMI) of 25.8 ± 3.5 kg/m2. Dietary intake, anthropometry, blood pressure, lifestyle features, and blood and urine biochemical data were assessed with validated procedures. The oxidative stress markers selected were plasma oxidized low-density lipoprotein (ox-LDL), urinary 8-iso-prostaglandin F2 α (8-iso-PGF2 α) and 8-hydroxy-2′-deoxyguanosine (8-OHdG).ResultsThe men included in the highest tertile of FV intake (≥341.1 g/d) displayed lower concentrations of ox-LDL, 8-iso-PGF2 α and 8-OHdG (P for trend < 0.05), regardless of confounding factors. Concentrations of ox-LDL were negatively associated with fiber from the FV intake (P for trend < 0.05) regardless of confounding factors. ox-LDL and 8-OHdG concentrations tended to be lower in the higher tertile of magnesium (P for trend = 0.06) and vitamin C from FV intake (P for trend = 0.05), respectively. Additionally, concentrations of 8-iso-PGF2 α were lower in men in the highest tertile of fiber (≥6.5 g/d; P for trend = 0.034), vitamin C (≥98.0 mg/d; P for trend = 0.007), and magnesium (≥48.9 mg/d; P for trend = 0.018) from the FV-group intake.ConclusionsGreater FV intake was independently associated with reduced ox-LDL, 8-OHdG, and 8-iso-PGF2 α in middle-aged men. Fiber, vitamin C, and magnesium from FV seem to contribute to this beneficial relationship.