Dietary intake of fruits and vegetables improves microvascular function in hypertensive subjects in a dose-dependent manner.
BACKGROUND
Observational evidence has consistently linked increased fruit and vegetable consumption with reduced cardiovascular morbidity; however, there is little direct trial evidence to support the concept that fruit and vegetable consumption improves vascular function. This study assessed the dose-dependent effects of a fruit and vegetable intervention on arterial health in subjects with hypertension.


RESULTS
After a 4-week run-in period during which fruit and vegetable intake was limited to 1 portion per day, participants were randomized to consume either 1, 3, or 6 portions daily for the next 8 weeks. Endothelium-dependent and -independent arterial vasodilator responses were assessed by venous occlusion plethysmography in the brachial circulation before and after intervention. Compliance was monitored with serial contemporaneous 4-day food records and by measuring concentrations of circulating dietary biomarkers. A total of 117 volunteers completed the 12-week study. Participants in the 1-, 3-, and 6-portions/d groups reported consuming on average 1.1, 3.2, and 5.6 portions of fruit and vegetables, respectively, and serum concentrations of lutein and beta-cryptoxanthin increased across the groups in a dose-dependent manner. For each 1-portion increase in reported fruit and vegetable consumption, there was a 6.2% improvement in forearm blood flow responses to intra-arterial administration of the endothelium-dependent vasodilator acetylcholine (P=0.03). There was no association between increased fruit and vegetable consumption and vasodilator responses to sodium nitroprusside, an endothelium-independent vasodilator.


CONCLUSIONS
The present study illustrates that among hypertensive volunteers, increased fruit and vegetable consumption produces significant improvements in an established marker of endothelial function and cardiovascular prognosis.
Nutrition and Metabolism Group, Centre for Public Health, Lower Ground Floor, Pathology Bldg, Grosvenor Rd, Belfast, BT12 6BJ, United Kingdom. d.o.mccall@qub.ac.uk
Damian O
DO
McCall
Claire P
CP
McGartland
Michelle C
MC
McKinley
Chris C
CC
Patterson
Peter
P
Sharpe
David R
DR
McCance
Ian S
IS
Young
Jayne V
JV
Woodside
D000109:Acetylcholine / Q000008:administration & dosage; D000328:Adult; D000368:Aged; D001916:Brachial Artery / Q000502:physiology; D015930:Diet Records; D004435:Eating; D005260:Female; D005638:Fruit; D006801:Humans; D006973:Hypertension / Q000178:diet therapy* / Q000503:physiopathology; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D018977:Micronutrients / Q000008:administration & dosage; D008875:Middle Aged; D010991:Plethysmography; D011379:Prognosis; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000008:administration & dosage; D014675:Vegetables
D018977:Micronutrients; D014665:Vasodilator Agents; D000109:Acetylcholine