Every portion of fruits and vegetables eaten per day improves vascular endothelial function by an additional 6.2 percent in dose-dependent fashion.
This finding from a randomized, controlled study provides a mechanistic explanation for the previously reported lower rates of cardiovascular events in people who eat more fruits and vegetables, observational studies 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.
“During this period, subjects received weekly home delivery of self-chosen fruits and vegetables and written instructions as to how portions are defined,” said Queen’s University of Belfast (Northern Ireland).
Food diaries indicated that compliance with the assigned regiments was good, which was objectively confirmed by periodic measurement of serum levels of lutein and other micronutrients associated with fruits and vegetables.
Noted that the new findings from the randomized, controlled intake study are consistent with the results of a meta-analysis of nine observational studies totaling more than 221,000 patients with more than 5,000 coronary heart disease events. The investigators concluded that the risk of coronary disease dropped by 4 percent for each additional daily portion of fruits and vegetables.
Similarly, British investigators conducted a meta-analysis of eight studies with more than 257,000 participants that showed a 26 percent reduction in stroke risk among those consuming more than five portions per day.
On the basis of such evidence, the American Heart Association has issued a scientific statement calling for the consumption of 8-10 portions of fruits and vegetables, including potatoes, per day. British Hypertension Society guidelines call for the consumption of at least five portions per day.