Previous research has shown that high dietary intake of fruit and vegetables is associated with reduced risks of cancer and cardiovascular disease. Short-term intensive dietary interventions in selected populations increase fruit and vegetable intake, raise plasma antioxidant concentrations, and lower blood pressure, but longer-term effects of interventions in the general population are unknown. Andrew Neil and colleagues from the University of Oxford, UK, assessed the effect of a six-month intervention to increase fruit and vegetable consumption on plasma concentrations of antioxidant vitamins, daily fruit and vegetable intake, and blood pressure.
690 people from a UK primary-care health centre were randomly allocated to either the intervention groupin which participants were encouraged to increase their fruit and vegetable consumption to at least five servings a day (one portion being an 80 gramme serving)or to a control group where participants were not instructed to alter their dietary habits.
Fruit and vegetable intake increased by 1.4 servings in the intervention group compared with a very small (0.1 serving) increase in the control group. Blood pressure decreased in the group with increased fruit and vegetable consumption compared with the control group (systolic pressure decrease of 4 mm Hg, diastolic decrease of 1.5 mm Hg); concentrations of a-carotene, b-carotene, lutein, b-cryptoxanthin, and ascorbic acid increased by more in the intervention group than in the control group. There were no changes in either bodyweight or cholesterol concentrations between the two groups, suggesting that the reduction in blood pressure was a result of the effect of increased fruit and vegetab
Contact: Richard Lane