New Evidence Fruit and Vegetable Intake Reduces Hypertension

[Guest guest]

New Evidence Fruit and Vegetable Intake Reduces Hypertension

Lancet

05/28/2002

By Harvey McConnell

New evidence that increasing average intake of fruit and vegetables to five

servings a day reduces blood pressure and cuts the risk of cardiovascular

disease has been shown by British researchers.

Dr Neil and colleagues from the Division of Public Health and Primary

Health Care, Institute of Health Sciences, University of Oxford, Oxford,

England, said their findings coincide with those of the Dietary Approaches

to Stop Hypertension (DASH) trial, in which an increase in dietary fruit and

vegetables for eight weeks reduced systolic blood pressure by 2.8 mm Hg and

diastolic pressure by 1.1 mm Hg more than a control diet.

On the other hand, they note that DASH differed fundamentallyin design,

since it was a controlled feeding trial with meals prepared according to a

common protocol in research kitchens.

The researchers 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, among 690

men and women between 25 and 64 years of age, drawn from primary care

patient lists.

Patients were assigned to either the intervention group, in which

participants were encouraged to increase their fruit and vegetable

consumption to at least five servings a day (one portion being an 80 gram

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.

Dr Neil and colleagues found that systolic and diastolic blood pressure

decreased more in the intervention group than in the control group. In

addition, concentrations of alpha-carotene, beta-carotene, lutein,

beta-cryptoxanthin, and ascorbic acid increased by more in the intervention

group than in the control group.

The researchers note that the falls in blood pressure observed in the study

would be expected to produce small clinical effects, but would substantially

reduce cardiovascular disease at the population level. A reduction of two mm

Hg in diastolic blood pressure results in a decrease of about 17 percent in

the incidence of high blood pressure, six percent in the risk of coronary

heart disease, and 15 percent in the risk of stroke and transient ischaemic

attack, they say.