December 2012 Issue
Eat to Lower Blood Pressure
Eating a low-sodium diet rich in fruits, vegetables, and grains can significantly lower your blood pressure.
High blood pressure is called the “silent killer,” because about one in three people have it, but many don’t even realize it. So, what if you’re one of those Americans with dangerous, high blood pressure? It’s essential to discuss a personalized plan of care, which may include medication, with your health care practitioner. And lifestyle—diet, exercise, and weight loss—is also key to managing it.
DASHing to health. In the mid 1990s, a consortium of researchers from several organizations, including Johns Hopkins, Duke, and Harvard set out to study the effects of diet on blood pressure in 450 adults enrolled in the landmark trial, Dietary Approaches to Stop Hypertension (DASH). Existing research had already found blood pressure-lowering benefits in dietary patterns that included vegetarian meal plans and dairy products. Thus, the DASH researchers wanted to investigate further the effects of a flexible diet plan, rich in fruits, vegetables, and low-fat dairy, and with reduced saturated and trans fats, that anyone could follow. After eight weeks of eating this DASH diet, blood pressure levels among the subjects were substantially reduced.
Thus, the DASH diet was born. “Since that time, studies reducing sodium and refined grains, on top of the DASH diet, lowered blood pressure even more than the original research,” says Marla Heller, M.S., R.D., author of “The DASH Diet Action Plan,” a book that offers practical advice based on the research of the DASH diet. Many more findings on the benefits of a DASH diet have accumulated since that first study. In the most recent study, published in the Journal of the Academy of Nutrition and Dietetics in September 2012, a program was featured that included the DASH diet, counseling and exercise that helped sedentary, overweight, and obese adults with hypertension lose an average of 19 pounds, as well as lower their blood pressure levels.
And the benefits of the DASH diet extend beyond hypertension. “There are a great many benefits in addition to blood pressure lowering. Epidemiological studies that follow people for long periods of time found that people who eat a diet consistent with the DASH diet are much less likely to experience heart attack, stroke, heart failure, colon cancer, and certain other types of cancer,” says Heller.
What’s the secret behind DASH? There is no one secret; it’s the entire dietary pattern of nutrient-rich foods working together. “The diet has a lot of fresh fruits, vegetables, nuts, beans, and seeds,” says Heller. “The theory is that the foods are rich in potassium, calcium and magnesium, which are beneficial. On the other hand, studies with those minerals added as supplements did not show consistent benefits. There is something in the pattern of foods; it may be all of the other nutrients, such as antioxidants, vitamin D, and high-quality protein. We know that this diet reduces inflammation; it does not contain a lot of refined sugars or refined grain products and it is high in fiber. It’s not going to cause swings in blood sugar, more hunger, or more inflammation. The benefit is in eating foods that are healthy, filling and low-calorie, so it’s easy to stay on track with healthy eating.”
The DASH diet up close. In a nutshell, the DASH eating plan is low in saturated fat, cholesterol, and total fat, and emphasizes fruits, vegetables, and fat-free or low-fat milk and milk products. It also includes whole grain products, fish, poultry, and nuts and is low in lean red meat, sweets, added sugars, and sugar-containing beverages. The meal plan is also lower in sodium than the typical American diet. The meal plans are recommended at two levels: 2,300 milligrams (mg) and 1,500 mg of sodium per day. While 2,300 mg is the highest level recommended by the National High Blood Pressure Education Program, 1,500 mg can lower blood pressure even further and is the amount recommended by the Institute of Medicine that most people should aim for.
DASH diet meal plans are available for different calorie levels to promote a healthy weight. “Weight loss is recommended for people who need it. You can calculate your needs in order to determine which meal plan you should follow,” says Heller. DASH meal plans are available at http://www.nhlbi.nih.gov/.
Don’t forget exercise. The best effects are seen when exercise is combined with diet, so remember to include 30 minutes of moderate-intensity physical activity, such as walking, every day. This level of exercise may be enough to keep you off medication, make your medications more effective, or even lower your chances of developing high blood pressure to begin with.
Good for everyone! The DASH diet got a big plug when U.S. News rated it as “The Best Diet Overall” in their 2012 evaluation of diets, which was based on the input of 22 leading nutrition experts who evaluated 28 popular diet plans. Even if you don’t have high blood pressure, the DASH diet is a model plan to promote healthy weight, optimal health, and to lower chronic disease risk. Says Heller, “It’s a blueprint for a healthy diet for everyone.”
—Sharon Palmer, R.D.