title: Association between plasma vitamin C concentrations and blood pressure in the European prospective investigation into cancer-Norfolk population-based study.
abstract: The effect of fruit and vegetable consumption and blood pressure is unclear. A population-based cross-sectional study was conducted in 20 926 men and women aged 40 to 79 years participating in the European Prospective Investigation Into Cancer-Norfolk who completed a health questionnaire and attended a clinic from 1993 to 1997. The relationship between plasma vitamin C concentrations, as an indicator of fruit and vegetable intake, and systolic BP was examined. The magnitude of their association was assessed using dichotomized values of high (≥140 mm Hg) and low (<140 mm Hg) systolic blood pressure. A total of 20 926 participants (46% men; mean [SD] 58.5 years [9.2 years]) were included after excluding participants with any missing data for variables of interest. People with high vitamin C concentrations had lower clinic blood pressure. The likelihood of having high blood pressure was 22% lower (odds ratio: 0.78 [95% CI: 0.71 to 0.86]) for those who were in the top quartiles of plasma vitamin C levels compared with the bottom quartiles after adjusting for age, sex, body mass index, cholesterol, prevalent medical conditions, smoking, physical activity, alcohol consumption, social class, education, use of vitamin C-containing supplement, and antihypertensive medication. Sex-specific analysis, as well as repeated analysis after exclusion of people who used vitamin C-containing supplements or who were taking antihypertensive medication, did not alter the results. There appears to be a strong association between vitamin C concentrations, an indicator of fruit and vegetable consumption, and a lower level of blood pressure. This may provide further evidence for health benefits of dietary patterns with higher fruit and vegetable consumption.
authors.affiliation: Norwich Medical School, Chancellors Drive, University of East Anglia, Norwich NR4 7TJ, UK. phyo.k.myint@uea.ac.uk
authors.forename: Phyo K
authors.initials: PK
authors.lastname: Myint
authors.forename: Robert N
authors.initials: RN
authors.lastname: Luben
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Wareham
authors.forename: Kay-Tee
authors.initials: KT
authors.lastname: Khaw
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001205:Ascorbic Acid / Q000097:blood*; D001794:Blood Pressure; D003430:Cross-Sectional Studies; D005060:Europe; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000503:physiopathology / Q000517:prevention & control; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009369:Neoplasms / Q000517:prevention & control; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D006113:United Kingdom
chemical_list: D001205:Ascorbic Acid