title: Beneficial effect of a polyphenol-rich diet on cardiovascular risk: a randomised control trial.
abstract: There is previous epidemiological evidence that intake of polyphenol-rich foods has been associated with reduced cardiovascular disease risk. We aimed to investigate the effect of increasing dietary polyphenol intake on microvascular function in hypertensive participants.
  
  
  
  All participants completed a 4-week run-in phase, consuming <2 portions of fruit and vegetables (F&V) daily and avoiding berries and dark chocolate. Subjects were then randomised to continue with the low-polyphenol diet for 8 weeks or to consume a high-polyphenol diet of six portions F&V (including one portion of berries/day and 50 g of dark chocolate). Endothelium-dependent (acetylcholine, ACh) and endothelium-independent (sodium nitroprusside) vasodilator responses were assessed by venous occlusion plethysmography. Compliance with the intervention was measured using food diaries and biochemical markers.
  
  
  
  Final analysis of the primary endpoint was conducted on 92 participants. Between-group comparison of change in maximum % response to ACh revealed a significant improvement in the high-polyphenol group (p=0.02). There was a significantly larger increase in vitamin C, carotenoids and epicatechin in the high-polyphenol group (between-group difference p<0.001; p<0.001; p=0.008, respectively).
  
  
  
  This study has shown that increasing the polyphenol content of the diet via consumption of F&V, berries and dark chocolate results in a significant improvement in an established marker of cardiovascular risk in hypertensive participants.
  
  
  
  NCT01319786.
authors.affiliation: Centre for Public Health, Queen's University Belfast, Belfast, UK Cardiology Department, Belfast Health and Social Care Trust, Belfast, UK.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Noad
authors.affiliation: Centre for Public Health, Queen's University Belfast, Belfast, UK.
authors.forename: Ciara
authors.initials: C
authors.lastname: Rooney
authors.affiliation: Cardiology Department, Belfast Health and Social Care Trust, Belfast, UK.
authors.forename: Damian
authors.initials: D
authors.lastname: McCall
authors.affiliation: Centre for Public Health, Queen's University Belfast, Belfast, UK Cardiology Department, Belfast Health and Social Care Trust, Belfast, UK.
authors.forename: Ian S
authors.initials: IS
authors.lastname: Young
authors.affiliation: Cardiology Department, Belfast Health and Social Care Trust, Belfast, UK.
authors.forename: David
authors.initials: D
authors.lastname: McCance
authors.affiliation: Centre for Public Health, Queen's University Belfast, Belfast, UK UKCRC Centre of Excellence for Public Health, Queen's University Belfast, Belfast, UK.
authors.forename: Michelle C
authors.initials: MC
authors.lastname: McKinley
authors.affiliation: Centre for Public Health, Queen's University Belfast, Belfast, UK UKCRC Centre of Excellence for Public Health, Queen's University Belfast, Belfast, UK.
authors.forename: Jayne V
authors.initials: JV
authors.lastname: Woodside
authors.affiliation: Centre for Public Health, Queen's University Belfast, Belfast, UK Cardiology Department, Belfast Health and Social Care Trust, Belfast, UK.
authors.forename: Pascal P
authors.initials: PP
authors.lastname: McKeown
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D000069956:Chocolate; D000072001:Diet, Healthy; D038441:Diet, Mediterranean; D005260:Female; D005638:Fruit; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000175:diagnosis / Q000178:diet therapy* / Q000503:physiopathology; D008297:Male; D008833:Microcirculation; D055806:Microvessels / Q000503:physiopathology*; D008875:Middle Aged; D009660:Northern Ireland; D010349:Patient Compliance; D059808:Polyphenols / Q000008:administration & dosage* / Q000097:blood; D064167:Recommended Dietary Allowances; D016037:Single-Blind Method; D013997:Time Factors; D016896:Treatment Outcome; D014664:Vasodilation; D014675:Vegetables
chemical_list: D015415:Biomarkers; D059808:Polyphenols