title: The effect of coffee consumption on blood pressure and the development of hypertension:  a systematic review and meta-analysis.
abstract: BACKGROUND
  Coffee is one of the most widely consumed beverages worldwide and is known to acutely raise blood pressure (BP), but the effects of chronic consumption on BP is unclear.
  
  
  OBJECTIVE
  To conduct a systematic review and meta-analysis of available randomized controlled trials (RCTs) and cohort studies to assess the effect of chronic coffee consumption on BP and the development of hypertension.
  
  
  METHODS
  Ovid, MEDLINE (from 1948), EMBASE (from 1988), and all of Web of Science and Scopus.
  
  
  METHODS
  RCTs and cohort studies of at least 1-week duration that assessed BP and/or the incidence of hypertension in coffee consumers compared with a control group that consumed less or no coffee.
  
  
  METHODS
  Two authors independently reviewed abstracts and full-text articles for inclusion. Data were abstracted using standardized forms. Risk of bias in the RCTs was examined using the method described in the Cochrane Handbook for Systematic Reviews of Interventions. Quality of the cohort studies were assessed using the Newcastle-Ottawa quality assessment scale for cohort studies.
  
  
  RESULTS
  Six hundred and ten articles were retrieved and a total of 15 (10 RCTs and five cohort studies) met inclusion criteria. Meta-analysis of RCTs demonstrated a pooled weighted difference in mean change in SBP of -0.55 mmHg [95% confidence interval (CI) -2.46 to 1.36) and DBP -0.45 mmHg (95% CI -1.52 to 0.61). Meta-analysis of the cohort studies demonstrated a pooled risk ratio for developing hypertension of 1.03 (95% CI 0.98-1.08).
  
  
  CONCLUSIONS
  Low-quality evidence did not show any statistically significant effect of coffee consumption on BP or the risk of hypertension. Given the quality of the currently available evidence, no recommendation can be made for or against coffee consumption as it relates to BP and hypertension.
authors.affiliation: Division of Preventive, Occupational, and Aerospace Medicine, College of Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Steffen
authors.forename: Carol
authors.initials: C
authors.lastname: Kuhle
authors.forename: Donald
authors.initials: D
authors.lastname: Hensrud
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: Erwin
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Murad
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D003069:Coffee; D004327:Drinking Behavior / Q000502:physiology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D012307:Risk Factors
chemical_list: D003069:Coffee