Flavonoid-rich fruit and vegetables improve microvascular reactivity and inflammatory status in men at risk of cardiovascular disease--FLAVURS: a randomized controlled trial.
BACKGROUND
Observed associations between increased fruit and vegetable (F&V) consumption, particularly those F&Vs that are rich in flavonoids, and vascular health improvements require confirmation in adequately powered randomized controlled trials.


OBJECTIVE
This study was designed to measure the dose-response relation between high-flavonoid (HF), low-flavonoid (LF), and habitual F&V intakes and vascular function and other cardiovascular disease (CVD) risk indicators.


METHODS
A single-blind, dose-dependent, parallel randomized controlled dietary intervention study was conducted. Male and female low-F&V consumers who had a ≥ 1.5-fold increased risk of CVD (n = 174) were randomly assigned to receive an HF F&V, an LF F&V, or a habitual diet, with HF and LF F&V amounts sequentially increasing by 2, 4, and 6 (+2, +4, and +6) portions/d every 6 wk over habitual intakes. Microvascular reactivity (laser Doppler imaging with iontophoresis), arterial stiffness [pulse wave velocity, pulse wave analysis (PWA)], 24-h ambulatory blood pressure, and biomarkers of nitric oxide (NO), vascular function, and inflammation were determined at baseline and at 6, 12, and 18 wk.


RESULTS
In men, the HF F&V diet increased endothelium-dependent microvascular reactivity (P = 0.017) with +2 portions/d (at 6 wk) and reduced C-reactive protein (P = 0.001), E-selectin (P = 0.0005), and vascular cell adhesion molecule (P = 0.0468) with +4 portions/d (at 12 wk). HF F&Vs increased plasma NO (P = 0.0243) with +4 portions/d (at 12 wk) in the group as a whole. An increase in F&Vs, regardless of flavonoid content in the groups as a whole, mitigated increases in vascular stiffness measured by PWA (P = 0.0065) and reductions in NO (P = 0.0299) in the control group.


CONCLUSIONS
These data support recommendations to increase F&V intake to ≥ 6 portions daily, with additional benefit from F&Vs that are rich in flavonoids, particularly in men with an increased risk of CVD.
Hugh Sinclair Unit of Human Nutrition (ALM, TWG, MFC, DSA, YJ, AV, JPES, OBK, KMT, A-MM, MHG, and JAL), and the Institute for Cardiovascular and Metabolic Research, Department of Food and Nutritional Sciences (ALM and JAL), University of Reading, Reading, Berkshire, United Kingdom.
Anna L
AL
Macready
Trevor W
TW
George
Mary F
MF
Chong
Dauren S
DS
Alimbetov
Yannan
Y
Jin
Alberto
A
Vidal
Jeremy P E
JP
Spencer
Orla B
OB
Kennedy
Kieran M
KM
Tuohy
Anne-Marie
AM
Minihane
Michael H
MH
Gordon
Julie A
JA
Lovegrove
D000328:Adult; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000276:immunology / Q000503:physiopathology / Q000517:prevention & control*; D015331:Cohort Studies; D016207:Cytokines / Q000037:antagonists & inhibitors / Q000097:blood; D004739:England / Q000453:epidemiology; D005260:Female; D005419:Flavonoids / Q000627:therapeutic use*; D005638:Fruit / Q000737:chemistry*; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000517:prevention & control; D008297:Male; D055806:Microvessels / Q000276:immunology / Q000502:physiology* / Q000503:physiopathology; D008875:Middle Aged; D012307:Risk Factors; D012727:Sex Characteristics; D016037:Single-Blind Method; D014655:Vascular Resistance; D059289:Vascular Stiffness; D014675:Vegetables / Q000737:chemistry*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D015415:Biomarkers; D016207:Cytokines; D005419:Flavonoids