Why is blood pressure important? Because high blood pressure, also called hypertension, affects millions of people in the US (and about 1/3 don't even know it!). It is the major treatable risk factor for heart disease and stroke. Yet only half of those with hypertension are being treated for it, and only half of those being treated have the disorder under control. In the past 20 years, deaths from coronary artery disease in the U.S. have fallen by 53%, and from stroke by nearly 60% - in large part because of better detection of and treatments for hypertension and heart disease.

How blood pressure turns into hypertension

Blood pressure is created by the pumping of your heart - a variable force that moves blood through the circulatory system. When your heart contracts, blood flows into the arteries, and at the end of the contraction the pressure exerted on the walls of the vessels is at its highest. Then as the heart relaxes, blood flows from the veins into the heart, and the pressure falls to its lowest level. Thus blood pressure is expressed as two numbers: systolic (high point, during a contraction) and diastolic (low point, between heart beats). It is best if blood pressure is kept below 120/80 mmHg. "Prehypertension" is defined as blood pressure above 120/80 mmHg but below 140/90 mmHg. High blood pressure is defined as a blood pressure greater than 140/90 mmHg (though in diabetics, we consider greater than 130/80 mmHg to be a concern).

How can I prevent hypertension?

Besides taking drugs, if that becomes necessary, how can I control it if I have it? It's not certain that you can prevent it, but it's reasonable to think that the same practices that help control it might also prevent or postpone it.

What about calcium, potassium, magnesium?

These three minerals are important in blood pressure regulation. But there's no evidence that high doses of them from supplements will lower blood pressure and help prevent hypertension. Calcium supplements are a good idea for postmenopausal women, but we strongly suggest that you get some calcium and all your potassium and magnesium from foods, which also contain other nutrients you need. Nonfat or low-fat dairy products are the best sources of calcium, though some leafy greens are good, too. You need at least 800 to 1,000 milligrams of calcium daily; women over 50 and men over 65 should get 1,500 milligrams daily. Potassium is plentiful in most foods. Magnesium is plentiful in whole grains, leafy greens, meats, milk, beans, bananas, and nuts.

An eating plan to lower blood pressure - the DASH diet

This is a plan worth making a DASH for - so called because the study (published last year in the New England Journal of Medicine) demonstrating its benefits was called Dietary Approaches to Stop Hypertension. This version of the DASH diet is adapted from the Sixth Report of the Joint National Committee. It is rich in fruits, vegetables, and low-fat or nonfat dairy products, low in total fat and cholesterol, and high in fiber. It supplies beneficial amounts of potassium, calcium, and magnesium. The plan is based on 2,000 calories a day.

FoodServingsServing SizeExamples
Grains7-8/day1 slice of bread, 1/2 cup of cooked ricewhole wheat bread, pita, whole wheat bagel, brown rice, whole wheat pasta, oatmeal
Vegetables4-5/day1 cup raw leafy greens, 1/2 cup cooked vegetablestomatoes, potatoes, peas, carrots, squash, spinach, beans, kale, broccoli, sweet potato
Fruits4-5/day1 medium fruit, 6 oz real fruit juice, 1/4 cup dried fruit, 1/4 cup fresh/frozen/canned fruitapricots, bananas, grapes, oranges, grapefruit (not if you take a statin), mangoes, peaches, prunes, raisins
Low-fat or nonfat diary products2-3/day8 oz milk, 1 cup yogurt, 1.5 oz cheesenonfat or 1% milk, nonfat or part-skim cheese
Fish, poultry (and meat)No more than 2/day3 oz cookedlean only; trim all visible fat; broil, roast, or boil; skinless poultry only
Nuts, seeds, legumes4-5 per week (may substitute legumes for fish/poultry/meat serving)1.5 oz (1/3 cup) nuts, 1/4 oz (2 tsp) seeds, 1/2 cup cooked legumesalmonds, hazelnuts, cashews, walnuts, sunflower seeds, kidney beans, lentils, pinto beans, black beans