Those who have high blood pressure or hypertension might want to consider increasing plant foods such as fruits and veggies and decreasing meat products in their diet.

A new study, published in the December, 2005 issue of the American Journal of Clinical Nutrition, found high intake of plant foods such as vegetables and fruit lowered risk of high blood pressure whereas high intake of meat raised the risk.

For the study, Dr. Lyn M. Steffen, from the University of Minnesota in Minneapolis, and colleagues evaluated the association between dietary habits and levels of blood pressure (BP) in 4,304 women and men aged 18 to 30 for a period of 15 years.

In the study, high blood pressure was defined as systolic BP over 130 and/or diastolic BP over 85 or use of high blood pressure medication. Plants foods included whole grains, refined grains, fruit, vegetables, nuts and legumes.

There was an inverse association between consumption of whole grain, fruit, nuts, and milk and blood pressure level. Compared to the lowest quintile of plant food intake, the second and fifth quintiles of intake reduced the risk by 27% and 36%, respectively.

Consumption of red and processed meat was linked with increased risk of high blood pressure. The connection of dairy products with the risk was not consistent, according to the study.

The researchers suggested that high intakes of plant foods and low intakes of meat products may help high blood pressure treatment.

The current finding echoed previous studies in that fruits, vegetables, and low-fat diet lower blood pressure.

For example, after studying 459 adults, among whom 133 had hypertension, for an eight-week period, Dr. Lawrence J. Appel of Johns Hopkins University and colleagues reported in 1997 in the New England Journal of Medicine (1997; 336: 1117-24) that a diet rich in fruits and vegetables combined with low-fat dairy foods and with reduced saturated and total fat can significantly reduce blood pressure, especially in hypertension patients.

Another study, conducted by Christian K. Roberts, Nostratola D. Vaziri, and R. James Barnard of the University of California Los Angeles, involved eleven obese men aged 38 to 72 with a body mass index of at least 30. Researchers put the subjects on a low-fat, high-fiber diet and combined it with 45 to 60 minutes of brisk walking on a treadmill daily for three weeks.

They found the diet-exercise regimen can significantly reduce blood pressure, cholesterol, insulin levels, and glucose while it does not affect much of the body weight. The participants lowered their cholesterol by 19% and blood pressure by 14%, the insulin level by 46% and glucose by 7%.

Recognizing the important effect of a diet on blood pressure, the National Heart, Lung and Blood Institute (NHLBI) has been promoting a diet called DASH diet (Dietary Approaches to Stop Hypertension Diet) for hypertension prevention. Studies showed the DASH diet consisting of fruits and vegetables as well as low-fat dairy and meat products can lower both systolic and diastolic blood pressure in a matter of two weeks.

Some researchers attribute the blood pressure-lowering effect of DASH diet to its rich content of three minerals, calcium, potassium and magnesium from vegetables, fruits and dairy products. But this explanation has not been exclusively accepted although earlier studies have shown that those eating diets full of potassium-rich foods such as bananas, dates, potatoes, and raisins tend to have lower blood pressure.

Based on intake of 2000 kcal a day, the DASH diet consists of grains (7-8 servings); vegetables (4-5); fruits (4-5); lowfat or fat-free dairy (2-3); meats, poultry & fish (2 or less); nuts, seeds & dry beans (4-5 per week), fats & oils (2-3 per week); and sweets (5 per week).

Previously known risk factors that may cause high blood pressure include obesity, high sodium intake, and alcohol consumption. Chronically high blood pressure or hypertension, a risk of stroke and heart disease, affects more than 40 million Americans.