Data on dietary intake, cardiometabolic biomarkers, and chronic disease incidence from the 3 large prospective cohort studies were pooled and analyzed. The analyses were adjusted for various factors, including demographics, lifestyle, health status, and medical history.

Dietary intake was estimated using validated semi-quantitative food frequency questionnaires, cardiometabolic biomarkers were assessed from blood samples, and chronic disease incidence was collected from self-administered questionnaires.

FVs with a high metabolic quality were identified by associations between individual FV intake and cardiometabolic biomarkers that were categorized by their biological mechanism:

Insulinemic/glycemic: C-peptide, HbA1c
Inflammatory: CRP, IL-6, TNF-alpha receptors 1 and 2
Endothelial function: intercellular adhesion molecule-1
Adipokines: adiponectin, leptin
Lipids: TC, HDL-cholesterol, LDL-cholesterol, TG, TC/HDL-c ratio

An individual FV received 1 point if a 1-serving-per-day increase in intake was significantly associated with improved concentrations or at least a 5% improved concentration of a cardiometabolic biomarker, even if the increase was not statistically significant. FVs with scores of at least 2 were considered to be of high metabolic quality.

Fruit and vegetable intake and risk of chronic disease Original paper