Fruit and vegetable intake and the association with glucose parameters: a cross-sectional analysis of the Let's Prevent Diabetes Study

Eur J Clin Nutr. 2013 Jan;67(1):12-7. doi: 10.1038/ejcn.2012.174. Epub 2012 Nov 7.


Background: Dietary recommendations for the prevention of type 2 diabetes mellitus include the message to consume 400 g fruit and vegetables per day. Measurement of habitual diet is inherently difficult, yet errors due to self-report can be eliminated by the use of nutritional biomarkers. The aim of this study was to determine plasma vitamin C concentrations as a biomarker for fruit and vegetable intake in individuals identified at high risk of diabetes. Fruit and vegetables may confer benefit via their antioxidant capacity, thus we also measured urinary F₂-isoprostanes as a marker for oxidative stress.

Subjects/methods: Participants recruited from a high-risk population as part of a diabetes prevention trial provided fasting blood samples and a spot urine sample for the quantification of plasma vitamin C and F₂-isoprostanes, respectively. We compared glycaemic parameters by the increments of the standard deviation of plasma vitamin C using multiple regression models.

Results: Mean plasma vitamin C of participants was 39.3 μmol/l (s.d. 21.8). In the unadjusted model, 1 s.d. plasma vitamin C was significantly and inversely associated with HbA1c, fasting and 2 h blood glucose (P ≤ 0.0001). Relationships remained significant after adjustment for demographic variables and confounding factors. No significant association was observed between plasma vitamin C and urinary F₂-isoprostanes.

Conclusion: The data adds to the evidence that small lifestyle changes may influence glucose regulation. The role that fruit and vegetables independently have should be investigated further.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Ascorbic Acid / blood
  • Biomarkers / blood
  • Biomarkers / urine
  • Blood Glucose
  • Cohort Studies
  • Cross-Sectional Studies
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / epidemiology
  • Diabetes Mellitus, Type 2 / prevention & control*
  • Diabetes Mellitus, Type 2 / urine
  • England / epidemiology
  • F2-Isoprostanes / urine
  • Female
  • Fruit*
  • Glycated Hemoglobin A / analysis
  • Humans
  • Male
  • Middle Aged
  • Oxidative Stress
  • Risk
  • Sex Characteristics
  • Vegetables*


  • Biomarkers
  • Blood Glucose
  • F2-Isoprostanes
  • Glycated Hemoglobin A
  • hemoglobin A1c protein, human
  • Ascorbic Acid

Associated data

  • ISRCTN/ISRCTN80605705