Eat More Fruits and Vegetables

Eating more fruit and vegetables improves vascular health in dose-dependent manner, a recently reported trial shows

Dr. Damian McCall (academic clinical lecturer in the nutrition and metabolism group at Queen's University in Belfast, Northern Ireland) presented his data at the American Heart Association meeting. He said that previous observational evidence suggested coronary disease risk is reduced by 4% per daily portion of fruit and vegetables, and stroke risk is lowered by 26* for people consuming more than five portions daily.

Dr. McCall and his team used a different approach, with vascular endothelial function (the endothelium are the cells that line our arteries) as the outcome measurement of the effects of the amounts of fruits and vegetables.
118 participants who had hypertension and were overweight (average body mass index was 29), were asked to limit fruit and vegetable consumption to one portion daily for four weeks, and were then randomly assigned to consume one, three or six servings of fruit and vegetables daily for another eight weeks.

Subjects received weekly home deliveries of their chosen foods, along with instructions on how a portion is defined in simple household measures. Compliance was good, as assess by food diaries and serum micronutrient levels. Endothelial function was assessed at randomization and at eight weeks by forearm blood flow in response to a local infusion of acetylcholine. (This challenges the endothelial cells to contract).

There was a statistically significant trend toward better endothelial function with more servings of fruit and vegetables. This equated to a 6.2% improvement in forearm blood flow for each daily portion consumed.

For me, these findings only confirm the benefits of fruits and vegetables. It's interesting that we can now quantify benefit by challenging the arteries to contract and measure blood flow. We also know the benefits of these products for cancer reduction, blood pressure reduction, lowering of cholesterol and improvement in diabetes. Similarly, an increase in fruits and vegetables displaces calories from other foods which are more calorie dense, so they can be used as a way to lose weight. (Being more satiated from these low calorie foods, than other high calorie foods.)