NEW ORLEANS — Every portion of fruits and vegetables eaten per day improves vascular endothelial function by an additional 6.2% in dose-dependent fashion.
This finding from a randomized controlled study provides a mechanistic explanation for the previously reported reduced rates of cardiovascular events in people who eat more fruits and vegetables in observational studies, Damian McCall, Ph.D., said at the annual scientific sessions of the American Heart Association.
The 118 participants in the randomized trial were overweight and mildly hypertensive (mean blood pressure, 143/83 mm Hg). After a month-long run-in period, during which they limited their fruit and vegetable consumption to one portion daily, they underwent a baseline evaluation of brachial artery vasodilation in response to acetylcholine infusion. Then they were randomized to 8 weeks of consumption of one, three, or six portions of fruits and vegetables per day, said Dr. McCall of Queen's University of Belfast (Northern Ireland).
Dr. McCall noted that the new findings from the randomized, controlled intake study are consistent with the results of a meta-analysis involving 221,000 men and women (J. Nutr. 2006;136:2588–93).
Similarly, investigators at St. George's University of London conducted a meta-analysis of eight studies with more than 257,000 participants that showed a 26% reduction in stroke risk among those consuming more than five portions per day (Lancet 2006;367:320–6).
Dr. McCall's study was sponsored by the U.K. Food Standards Agency.