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Low-fat dairy products linked to better blood pressure
Eating low-fat dairy products could lower your blood pressure, according to research reported in Hypertension.
Millions of Americans are affected by high blood pressure (HBP), and it is a major risk for stroke, heart attack, kidney failure and heart failure. HBP also incurs higher health care costs.
Non-drug approaches to lowering blood pressure include exercise, weight loss and the well-known Dietary Approaches to Stop Hypertension (DASH) diet, which is low in salt and rich in fruits, vegetables and low-fat dairy products. The DASH diet is also rich in the minerals potassium, magnesium and calcium, which are found in dairy products.
However, studies on calcium have had inconsistent results, with several showing no effect on blood pressure, said Luc Djoussé, M.D., M.P.H., D.Sc., lead author of the study and an assistant professor of medicine at Harvard Medical School in Boston, Mass.
“We need to find other dietary factors that could help prevent the disease,” said Djoussé, who is also an associate epidemiologist at Brigham and Women’s Hospital in Boston.
He noted that although low-fat dairy products are considered beneficial, no conclusive studies explain why. That has caused scientists to wonder whether dairy’s calcium content or some other unidentified components provide the apparent benefits.
“Dairy products, such as cheese, yogurt, and milk, are excellent sources of calcium,” Djoussé said. “However, some dairy products also contain substantial amounts of saturated fat, which might offset some of the beneficial effects of dairy products. In this study, magnesium and potassium intake was associated with lower blood pressure, but calcium was not.”
The researchers used data from food questionnaires from 4,797 men and women participants in the National Heart, Lung, and Blood Institute’s Family Heart Study. Participants consisted of 45 percent men, 55 percent women with an average age of 52 years. Four percent of the participants were black. The goal of this multi-center, population-based study is to identify and evaluate genetic and non-genetic causes of coronary heart disease, atherosclerosis and cardiovascular risk factors, such as HBP.
“Our data showed that people who ate more dairy products had lower systolic blood pressure,” Djoussé said.
Systolic blood pressure is the first (higher) number in a blood pressure reading; it indicates the pressure in the arteries when the heart beats. The lower (diastolic) number represents the pressure when the heart muscle is at rest between beats.
“Data from the Framingham Heart Study have shown that systolic blood pressure is a better predictor of cardiovascular disease in a dose-response fashion,” Djoussé said. “This means the higher your systolic pressure, the higher your risk of cardiovascular disease.”