Studies consistently show that lowering blood pressure significantly lowers the risk of stroke and also, though less dramatically, the risk of heart attacks, heart failure and kidney problems.
Drugs may be necessary sometimes, especially when blood pressure is dangerously high, but other things can help. Maybe you need to exercise a little harder and eat a little less (or sleep a little longer and stress a little less).
As you read, bear in mind: The evidence for blood pressure-lowering is stronger for some lifestyle measures than others.
Blood pressure basics
Blood pressure is measured in millimeters of mercury (mm Hg) at two points: when the heart beats (systolic) and between beats (diastolic). The systolic reading is usually stated in front of (or over) the diastolic one, for example, 110/75 mm Hg. Both numbers matter; after age 50, systolic becomes more key as it indicates how flexible your blood vessels are.
If your systolic blood pressure is 140 or higher, or your diastolic is 90 or higher, you have high blood pressure, or hypertension. If your systolic is between 120 and 139 or your diastolic is between 80 and 89, you have prehypertension -- you're at risk of developing high blood pressure, and your health risks are already elevated. If you have diabetes or kidney disease or have had previous cardiovascular problems, such as a heart attack or stroke, 130/80 mm Hg is the threshold for high blood pressure. About one-third of American adults have high blood pressure. Among those age 55, more than 90% either have it or will develop it.
Blood pressure fluctuates all day -- it goes down when you nap at your desk and comes back up (and then some) when your boss yells at you to wake up. "High blood pressure" refers to pressure that is chronically high. One bad reading isn't conclusive; doctors generally recommend several for a diagnosis.
High blood pressure is not usually curable. Even if you can get your pressure back below 120/80 mm Hg, you still have the condition and still need to treat it.
The DASH diet
DASH stands for Dietary Approaches to Stop Hypertension, an eight-week clinical trial, reported in 1997, that tested the effects of three diets on 459 adults. Among the group, 133 had high blood pressure for which they were not being treated with a drug.
One diet (the "control") was fairly similar to what many Americans eat; another was similar to that but with more fruits and vegetables and fewer snacks and treats. The third, which came to be known as the DASH diet, was rich in produce but also included a lot of low-fat dairy products and whole grains, as well as less saturated fat, total fat and cholesterol.
The fruit-and-vegetable group reduced their blood pressures compared with the control group, but the effects were greater for those in the DASH group, who reduced their blood pressure readings by averages of 5.5 mm Hg systolic pressure and 3 mm Hg diastolic pressure compared with the control group.
Reductions in blood pressures occurred for those who had high blood pressure (140 mm Hg or more) and those who didn't. But those who had high blood pressure lowered their blood pressure by about twice as much as the overall average.
The authors noted that the effects of the DASH diet were comparable to the effects of a single blood-pressure-lowering drug and speculated that, if everyone ate that way, the occurrence of heart disease and stroke could go down by 15% and 27%, respectively.
Attempts to show that the DASH diet reduces bad outcomes -- things like death and strokes as opposed to just high blood pressure -- haven't always been conclusive. But a 2008 report suggested the diet does lower the risk of heart disease and stroke, and two studies published last year found that it lowers the risk of heart failure in men and women.
Everyone agrees that stressful situations make your blood pressure take off. It's the fight-or-flight, prepare-to-do-something-dramatic response your ancient ancestors had when being charged by a woolly mammoth. Your body releases stress hormones that make your heart beat faster and your blood vessels constrict, and blood pressure rockets. When the stressful situation is resolved, blood pressure comes back down.
Some scientists suspect that getting stressed out too often can lead to chronic high blood pressure. That's not proved. But whenever blood pressure is higher than it should be, it increases wear and tear on the blood vessels. So a plethora of stress, leading to a plethora of blood pressure spikes, can do the same sort of damage that high blood pressure can do.
Plus scientists know that in stressful situations, people often smoke, drink and eat too much of the wrong foods -- all activities that can increase the risk for high blood pressure.