Print Email Facebook Twitter Contribution of caffeine to the homocysteine-raising effect of coffee: A randomized controlled trial in humans Title Contribution of caffeine to the homocysteine-raising effect of coffee: A randomized controlled trial in humans Author Verhoef, P. Pasman, W.J. van Vliet, T. Urgert, R. Katan, M.B. Centraal Instituut voor Voedingsonderzoek TNO TNO Voeding Publication year 2002 Abstract Background: A high plasma total homocysteine concentration is associated with increased risk of cardiovascular disease. Consumption of unfiltered or filtered coffee raises total homocysteine concentrations in healthy volunteers. The responsible compound, however, is unknown. Objective: The objective was to determine whether caffeine explains the homocysteine-raising effect of coffee. Design: Forty-eight subjects aged 19-65 y completed this randomized crossover study with 3 treatments, each lasting 2 wk. Subjects consumed 6 capsules providing 870 mg caffeine/d (test treatment), 0.9 L paper-filtered coffee providing ≈870 mg caffeine/d, or 6 placebo capsules. Blood samples were drawn fasting and 4 h after consumption of 0.45 L coffee or 3 capsules. Results: The mean fasting plasma homocysteine concentration after the placebo treatment was 9.6 ± 3.1 μmol/L. The caffeine and coffee treatments increased fasting homocysteine by 0.4 μmol/L (95% CI: 0.1, 0.7; P = 0.04), or 5%, and by 0.9 μmol/L (95% CI: 0.6, 1.2; P = 0.0001), or 11%, respectively, compared with placebo. The increase in homocysteine concentrations 4 h after consumption of 0.45 L coffee relative to consumption of 3 placebo capsules was 19% (P = 0.0001). Caffeine treatment had a much weaker acute effect on homocysteine (4%; P = 0.09). Effects of caffeine were stronger in women than in men, but the effects of coffee did not differ significantly between men and women. Conclusions: Caffeine is partly responsible for the homocysteineraising effect of coffee. Coffee, but not caffeine, affects homocysteine metabolism within hours after intake, although the effect is still substantial after an overnight fast. Chemicals/CAS: Caffeine, 58-08-2; Homocysteine, 454-28-4; Placebos; Vitamin B 12, 68-19-9; Vitamin B 6, 8059-24-3 Subject B vitaminsCaffeineCrossover experimentHomocysteinePaper-filtered coffeeCaffeineHomocysteineAdultAgedAmino acid metabolismClinical articleClinical trialCoffeeControlled clinical trialControlled studyCrossover procedureDiet restrictionDietary intakeFemaleHumanMaleRandomized controlled trialSex differenceAdultAgedCaffeineCoffeeCross-Over StudiesFastingFemaleHomocysteineHumansMaleMiddle AgedPlacebosSex CharacteristicsVitamin B 12Vitamin B 6 To reference this document use: http://resolver.tudelft.nl/uuid:6aa35f4b-faf9-470d-88e3-9c77b49d3b94 TNO identifier 236810 ISSN 0002-9165 Source American Journal of Clinical Nutrition, 76 (6), 1244-1248 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.