BackgroundEpidemiological evidence linking blood pressure (BP) and body weight-lowering effects with fruit and vegetable consumption mostly relies on self-reported dietary assessment prone to misreport and under- or overestimation of relationships. We characterized objective 24-hr urinary metabolites and a derived metabolite score associated with fruit and vegetable intake and assessed their associations with BP and body mass index (BMI), with validation across cohorts. MethodsWe used untargeted proton nuclear magnetic resonance spectroscopy (1H NMR) of two timed repeated 24-hr urine collections from free-living participants from the US (n=2,032) and the UK (n=449) of the cross-sectional International Study of Macro-/Micronutrients and Blood Pressure (INTERMAP). We evaluated correlations between fruit and vegetable intake assessed by 24-hr dietary recalls with 7,100 1H NMR features, adjusted for confounders and multiple testing. We related identified metabolites and a metabolite score with BP and BMI using extensively adjusted multiple linear regression models. ResultsWe characterized eleven 1H NMR-derived 24-hr urinary metabolites related to fruit and vegetable intake, reproducible across multiple 24-hr urine collections of both cohorts. Proline betaine, citrate, N-methylproline, scyllo-inositol, 2-hydroxy-2-(4-methyl cyclohex-3-en-1-yl) propoxyglucuronide, and proline were associated with fruit intake, specifically with Rutaceae intake, while S-methyl-L-cysteine sulfoxide and S-methyl-L-cysteine sulfoxide metabolite were associated with Brassicacea intake. The metabolite score, explaining 39.8% of fruit and vegetable intake, was inversely associated with systolic BP (-1.65 mmHg; 95% confidence interval (CI): -2.68,-0.62, P<0.002) and BMI (-1.21 kg/m2; 95% CI: -1.62,-0.78, P<0.0001). These associations were to a large extent explained by urinary citrate excretion. ConclusionWe identified 1H NMR-derived urinary metabolites associated with fruit and vegetable consumption, consistent and reproducible between urine collections and across populations. A higher fruit and vegetable-related metabolite score showed associations with lower systolic BP and BMI, mainly mediated by citrate, but would need confirmation in further studies. Study registrationThis study was registered at the clinicaltrials.gov registration (https://clinicaltrials.gov/study/NCT00005271?term=NCT00005271&rank=1) as NCT00005271.
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