Blood Pressure

About 30 million people in the United States have high blood pressure (hypertension), according to the latest figures from the National Center for Health Statistics. That makes it the third most prevalent chronic condition in the nation, right behind sinusitis and arthritis.

But more important than rank is what hypertension portends for older Americans. Of all the risk factors for heart attack, high blood pressure maintains an uncanny degree of accuracy for predicting exactly who will get cardiovascular disease after age 65.

On the up side, about 70 percent of patients have what's known as mild hypertension, that is, diastolic pressure that falls somewhere between 90 and 105 mm Hg. And for this population there have been some welcome changes in treatment. The emphasis is now being placed on nondrug therapy.

"For most people with mild hypertension, just about everyone now agrees that the nondrug approach should be the first line of defense—or should at least be tried," says Norman Kaplan, M.D., a noted blood pressure authority at the University of Texas Health Science Center at Dallas Southwestern Medical School.

The remedies below are designed to help those with mild hypertension attain good control over their condition. If you're already taking medication for your blood pressure, dosage levels may need to be adjusted. So consult your physician before implementing changes.

Watch your weight. "While there are a lot of hypertensives who are not fat, obese people tend to have three times as much hypertension as people of normal weight," says Dr. Kaplan.

Twenty percent above the ideal weight for your height and bone structure is where obesity starts. But obese people need not lose anywhere near that much to reduce high blood pressure. An Israeli study showed that stout people with high blood pressure can achieve normal pressures by losing only half of their excess weight, even though they remain "considerably obese."

"Even with relatively minor amounts of weight loss, one can see a measurable fall in blood pressure," Dr. Kaplan says. "We encourage obese people to lose all the weight they can. But if they can't lose a whole lot, at least whatever they do lose should give them some help with their blood pressure."

Shake the salt habit. The link between sodium and high blood pressure has never been proven beyond doubt. But what is known is that a salt-sensitive subset of hypertensives probably exists, and you may be one of them.

"There's no way to know if you're salt sensitive other than putting yourself on a low-sodium diet and seeing what effect that has on your blood pressure," Dr. Kaplan says. "So we just ask all our hypertensives to cut down on salt to about 5 grams a day and hope it has a good effect." While that's about half the salt in the typical American diet, Dr. Kaplan notes that "most people, once they cut down, really don't find they need as much salt as they thought they did." So keep the salt low, but don't count on it to do everything.

Cut down on alcohol. Because the connection between alcohol consumption and high blood pressure has been well documented, people with hypertension should limit their alcohol consumption.

Why not advise those with hypertension to simply cut out all drinking? Doctors probably would if studies hadn't shown that those who drink a small amount of alcohol a day have lower blood pressure than those who drink more than that, or those who don't drink at all.

"Two drinks or fewer a day will probably have no detrimental effect on blood pressure," says Dr. Kaplan, "but when you go beyond that, you're looking for trouble."

Pass the potassium, please. Increased levels of this mineral may be valuable in helping control high blood pressure. "The number of hypertensives who respond to potassium seems to depend on how long the studies are performed," says George Webb, Ph.D., a professor in the Department of Physics and Biophysics at the University of Vermont College of Medicine. "In a two-week study, we find that maybe 30 percent get a reduction, but with an eight-week study, we might find that 70 percent get a reduction," he says.

Dr. Webb believes that the total amount of potassium you consume isn't as important as maintaining the correct sodium/potassium ratio in your diet. "We believe there's a clear benefit when you get three times as much potassium as sodium," he says. "If you're on a low-salt diet and getting 2 grams of sodium (2 grams of sodium equals 5 grams of table salt) per day, then you should get 6 grams of potassium."

How do you know if you're getting enough? Well, it's virtually impossible to devise a low-salt diet that's not high in potassium. "And it's hard to avoid potassium if you eat plenty of natural foods," says Dr. Webb. Potatoes, fresh fruit, and fish are loaded with it. To calculate ratios, however, you may need to consult the tables of a nutrition reference book.

Make the calcium connection. "Calcium seems to have a favorable effect on some people," says Roseann Lyle, Ph.D., an assistant professor of health promotion and education at Purdue University. But the search to discover exactly who will respond favorably to calcium continues.

"It seems that salt-sensitive hypertensives, who may be about half the people with high blood pressure, are the same ones who respond well to calcium," says Lawrence M. Resnich, M.D., assistant professor at the New York Hospital-Cornell University Medical Center in New York City. "So if salt is bad for you, calcium's good for you."

Avoid isometrics. "Exercise, as part of a program to reduce hypertension, appears to add to the treatment," says David Spodick, M.D., director of clinical cardiology at St. Vincent's Hospital at the University of Massachusetts Medical School. But, he adds, isometric exercises such as weight lifting must be avoided. The reason is that weight-lifting exercises may cause blood pressure to temporarily skyrocket.

Try aerobic exercise instead. While numerous studies have shown the beneficial effects of aerobic exercise on high blood pressure, the primary advice for hypertensives is to proceed with caution.

"We usually start people with walking a quarter of a mile briskly," says Robert Cade, M.D., professor of medicine at the University of Florida College of Medicine. "Then we go up from there until a person can walk a mile briskly. After that we initiate running—but only after a physical exam and possibly a stress electrocardiogram."

The reason exercise works is that it forces the blood vessels to open up (vasodilate), and that makes the blood pressure come down, Dr. Cade says. "Even though it tends to go back up during exercise, it drops when exercise ends. Then when it goes back up, it doesn't go up as much."

Swimming, walking, and bike riding are all good exercises for hypertension. "You don't have to run," notes Cade. "You do about the same amount of work when you walk, it just takes longer to do it. The key thing is that it should be a brisk walk—a quarter mile in 4 minutes when you start, then later a full mile in about 15 minutes or less."

Think vegetarian. Studies have shown that vegetarians have lower blood pressure than the general population—10 to 15 mm Hg. lower for both systolic and diastolic pressures. The strange thing, however, is that nobody knows exactly why.

"But vegetarians do in fact have lower blood pressure," says Dr. Kaplan. "Maybe it's because people who follow vegetarian diets tend not to smoke, drink, or overeat.

Measure it yourself. "Blood pressure readings at home are to be encouraged," says Dr. Kaplan. "For anybody who has high blood pressure, it is by far the most sensible way to go about monitoring your condition."

But home monitoring can do more than just track your condition—it can help make you more aware of how diet, exercise, and medications are affecting your blood pressure. It may also help you overcome the "white coat" reaction many people experience. The minute they walk in a doctor's office, they tense up and their pressures rise dramatically.

Blood-pressure kits come in three basic categories, mechanical, electronic with manual cuff inflation, and electronic with automatic cuff inflation. The manual types require the use of a stethoscope, while the electronic types eliminate the stethoscope and are somewhat easier to use.

"I think the most practical are the electronic types with manual inflation," says Dr. Kaplan. "They cost about $60 or $70, but you can get a good reading without any training at all."

Be a happy person. A study at New York Hospital-Cornell University Medical Center showed that different emotions play a very specific role in determining how high or low your blood pressure may go.

When testing unmedicated hypertensive patients around the clock with high-tech monitors, researchers found that happiness caused systolic blood pressure to drop, while anxiety caused diastolic pressure to rise. They also found that blood pressure changes were directly related to emotional intensity, so that the happier a person felt, the more the systolic pressure fell. Conversely, the more anxiety a person experienced, the higher the diastolic pressure rose.

Researchers also discovered that anxiety experienced outside the home makes blood pressure increase significantly more than anxiety experienced inside the home. The lesson in all this could be summed up as follows: Don't worry, be happy—but if you must worry, do it at home.

Try talking less. While it's hardly surprising that arguing with your spouse or fighting with the boss can make blood pressure soar, research has shown that virtually any communication can put blood pressure on the rise.

Researchers at the University of Maryland discovered that speaking can cause blood pressure to increase by 10 to 50 percent, with hypertensive individuals showing the greatest increase. And this effect is not restricted to the spoken word—even the use of sign language by deaf people causes dramatic increases in their blood pressure.

This has caused some scientists to speculate that a general "communicating state" may exist in humans and that this state may somehow be linked to the heart, causing its activity to increase. If true, this increased activity could result in an unintended blood pressure rise during such innocent activities as talking to your doctor.

Check your spouse's pressure, too. You've probably heard that husbands and wives start looking alike after several years of marriage, but researchers have discovered an even stranger phenomenon. The longer two people are married, the more similar their blood pressures become.

The researchers who conducted the study suggest that this mimicking effect could have something to do with shared stress or other emotional factors. "Communication, particularly handling conflict and expressing emotions, may affect blood pressure levels between spouses," says one. So the next time the doctor says your pressure is up, have him check your spouse, too. If you're in your sixties, this study predicts your blood pressures will be only a point or so apart.

"Take one dog and call me in the morning." Pliny, the Roman writer and philosopher, first wrote that prescription (or something close to it) centuries ago, but modern science is showing that it's a valid treatment for high blood pressure.

Cindy Wilson, Ph.D., associate professor and research director at the Uniformed Services University of the Health Sciences, recorded the blood pressures of 92 college students, then asked them to read aloud, read silently, or interact with a friendly do. Reading aloud caused pressures to rise, though reading quietly or interacting with a dog resulted in blood pressure declines.

Her work only confirms the favorable feeling about pet therapy that some health professionals developed long ago. Other research had shown that coronary heart disease patients who are pet owners are more likely than nonowners to still be alive one year after discharge from a coronary care unit. And studies of children show that the presence of a pet reduces their blood pressure during reading or rest.

So what if Pliny wrote his prescription as a cure for women suffering from abdominal pains? Thanks to modern science, we now know that pets may be of benefit in hypertension, too.

PANEL OF ADVISERS

Robert Cade, M.D., is professor of medicine at the University of Florida College of Medicine in Gainesville.

Norman Kaplan, M.D., is a noted blood pressure authority at the University of Texas Health Science Center at Dallas Southwestern Medical School and coauthor of the book Travel Well, The Gourmet Guide to Healthy Travel.

Roseann Lyle, Ph.D., is assistant professor of health promotion and education at Purdue University in West Lafayette, Indiana, and has written a number of scientific papers about calcium and hypertension.

Lawrence M. Resnick, M.D., is an assistant professor of medicine at the New York Hospital-Cornell University Medical Center in New York City, and a prominent high blood pressure researcher.

David Spodick, M.D., is director of clinical cardiology at St. Vincent's Hospital at the University of Massachusetts Medical School in Worcester.

George Webb, Ph.D., is a professor in the Department of Physics and Biophysics at the University of Vermont College of Medicine in Burlington. He is coauthor of The K-Factor, a book about reducing high blood pressure through diet and exercise.