DASH stands for Dietary Approaches to Stop Hypertension, a strategy that has proved quite effective in lowering blood pressure. The diet involves consuming less salt and fat and more fruits, vegetables, whole grains, and low-fat dairy products. It's low in saturated fat, total fat, and cholesterol, and includes poultry, fish, and nuts, but includes much less red meat and fewer sweets and sugared beverages than most Americans are accustomed to consuming. Another version of the DASH diet limits sodium intake. By following the DASH diet, you should be able to pare 5.5 to 11.4 points off your systolic pressure (the top number in a blood pressure reading) and 3 to 5.5 points off your diastolic pressure (the bottom number in a blood pressure reading). Research also suggests that the diet reduces blood levels of homocysteine, a toxic amino acid that may increase the risk of heart disease, stroke, and peripheral vascular disease.
The DASH diet gives you 2,000 calories a day divided among 4 to 5 daily servings of vegetables, 4 to 5 servings of fruits, 2 to 3 servings of low-fat or nonfat dairy products, 7 to 8 servings of grain products, and only 2 small servings of meat. You're also allowed 4 to 5 small servings of nuts, beans, or seeds per week
Other strategies for lowering blood pressure are losing excess weight, exercising regularly, and reducing daily stress through meditation, breathing exercises, yoga, progressive muscle relaxation, or biofeedback.
The diet I recommend in my book Healthy Aging: A Lifelong Guide to your Physical and Spiritual Well-Being is similar to the DASH diet with the addition of omega-3 fatty acids and natural anti-inflammatory spices such as turmeric and ginger. Both are similar to the Mediterranean diet, which emphasizes fresh fruits and vegetables, crusty breads, whole grains, and olive oil as well as more fish and legumes and less meat and poultry than the typical Western diet contains. Whether you're trying to lower blood pressure or simply eat well, you can't go wrong with the DASH diet, or with the alternatives mentioned above.
I would only add that recent research indicates that saturated fat may not be associated with increased risk of coronary disease; indeed, some components of full-fat dairy foods may be cardioprotective. So while I approve of the DASH diet generally, its emphasis on low-fat dairy products may need revision in light of recent studies.
Andrew Weil, M.D.