High Blood Pressure
High
Blood Pressure
The Silent Thief of Youth
Wrinkles we can see. Sore muscles we can feel.
But there's a hidden aging problem out there, one that's far more dangerous than varicose veins, farsightedness or gray hair. High blood pressure, also called hypertension, is directly linked to the deaths of more than 18,000 American women each year--and it contributes to the deaths of untold thousands more. It can make us 12 times more likely to suffer strokes, 6 times more likely to suffer heart attacks and 5 times more likely to die of congestive heart failure. It's also a major risk factor for kidney failure.
And it's more common among younger women than many of us think. One in ten American women between the ages of 35 and 44 has high blood pressure. One in four of us develops high blood pressure before her 55th birthday. And after that, our risk is actually higher than that of men. Experts think hormonal changes play a role in the later development of high blood pressure in women.
Yet nearly half the people in this country with high blood pressure don't even know they have it. "There really aren't any noticeable outward signs. But if you have high blood pressure, it is doing damage," says Patrick Mulrow, M.D., chairman of the Department of Medicine at the Medical College of Ohio at Toledo and chairman of the American Heart Association's Council for High Blood Pressure Research.
"We could save lives if people discovered they have high blood pressure and then took measures to control it," Dr. Mulrow says. In many instances, it's just a matter of going to the doctor and having your blood pressure checked once or twice a year, cutting back on salt and fat and breaking a sweat a few times a week. That's really a small price to pay, Dr. Mulrow says, considering that it could add years to your life.
Try to Remember
If we have to keep reminding you to control your blood pressure, then maybe it's already too high. That's because high blood pressure may weaken your memory. A study of 100 adults found that people with higher blood pressure scored lower in a process called short-term memory retrieval. That means it took longer for them to remember whether a number shown to them had been part of an original set of numbers that they had seen earlier. No one's sure why high blood pressure fogs your memory. It may be related to the way blood circulates in the brain or to a reduction in the amount of oxygen that reaches the brain. "Whatever the mechanism, this is just another reason to keep your blood pressure under healthy control," says David J. Madden, Ph.D., professor in the Department of Psychiatry at Duke University Medical Center in Durham, North Carolina. |
Pressure Builders
Doctors take two measures when they check your blood pressure. The first is called the systolic reading. It indicates how hard your heart pumps to push blood through your arteries. The second measure, called the diastolic reading, shows how much resistance your arteries put up to the blood flow. Blood pressure is measured in millimeters of mercury, or mm Hg, and a reading of about 120 mm Hg systolic and 80 mm Hg diastolic is considered healthy. We read that simply as 120/80.
Everyone's blood pressure varies widely throughout the day. Generally, it will rise when we're exercising and drop when we're asleep. But when your baseline, or resting, reading creeps up to 140/90, you have borderline high blood pressure. That means your heart is working too hard to pump blood, either because your arteries have narrowed or stiffened with plaque or because you have too much blood in your system due to water retention or other problems. The result of the extra stress can be heart disease or dangerous blood clots that can cause stroke or heart attack.
Blood pressure tends to rise with age. A combination of factors causes this, including reduced physical activity, extra body weight and hormonal changes, according to Robert DiBianco, M.D., director of cardiology research at the Washington Adventist Hospital in Takoma Park, Maryland.
In 90 to 95 percent of cases, Dr. Mulrow says, the exact cause of high blood pressure is unknown. But researchers have identified a number of risk factors that may increase your risk of developing high blood pressure. Family history is one. If several members of your immediate family have high blood pressure, you're more likely to develop it. Black women and members of other minority groups are at higher risk than white women. Obesity is another major factor. Studies show that 60 percent of people with high blood pressure are overweight.
The Sodium-Stress Link
The amount of sodium in the foods we eat is one of the biggest contributors to high blood pressure, experts say. Sodium makes us retain water, Dr. Mulrow says, which increases the volume of blood in our bodies and makes our hearts work harder to pump it. There's also evidence that sodium in some way damages the linings of blood vessels, making scarring and clogged arteries more likely.
The vast majority of our sodium intake is from the salt in our foods (table salt is about 40 percent sodium). After analyzing dozens of studies on sodium and high blood pressure, one British research team found that cutting salt by 3,000 milligrams per day--that's a little less than a teaspoon's worth--could prevent 26 percent of all strokes and 15 percent of heart attacks caused by blood clots.
Some people are more sensitive than others to the effects of salt or, more specifically, of sodium, Dr. DiBianco says. "Maybe you can eat a lot of salt, process and get rid of it quickly and not have to worry about it," he says. But maybe not. There's no reliable test for salt sensitivity. If you are overweight, don't get a lot of exercise or have a family history of high blood pressure or diabetes, Dr. DiBianco says you're probably more at risk and need to limit your salt intake.
Psychological factors can also play a role in high blood pressure. A study of 129 college students at the University of British Columbia in Vancouver showed that women who felt they got little social support from friends, family members or co-workers had slightly higher systolic readings. Researchers are not sure why this is. Job stress may lead to high blood pressure, too. Another study of 129 working adults found that women with high-status, high-pressure jobs showed significantly bigger increases in blood pressure during the workday than those with less demanding jobs.
Scientists have found that the combination of too much sodium and high stress can create a powerful pressure problem. A study of 32 students at the Johns Hopkins University School of Medicine in Baltimore showed that people who ate high-sodium diets and faced high-stress conditions for a two-week period saw their systolic blood pressure readings jump more than 6 points. The high-sodium, low-stress people, by comparison, saw increases of just 0.6 point, and the low-sodium, high-stress people showed increases of just 0.1 point.
There's also a link between birth control pills and high blood pressure in some women, Dr. Mulrow says. The newer low-dose oral contraceptives have greatly decreased the problem of elevated blood pressure, although smoking and taking the Pill will increase your chances of high blood pressure, according to Dr. Mulrow.
Then there's alcohol. Scientists have long known that excess drinking can contribute to high blood pressure. But a study from the Research Institute on Alcoholism in Buffalo, New York, shows that how often you drink may be as important as how much you drink. Researchers looked at 1,635 residents of Erie County, New York, and found that people who drank every day had systolic readings 6.6 points higher and diastolic readings 4.7 points higher than people who drank only once a week. But the study found no significant relationship between blood pressure and the total amount of alcohol consumed.
How Low Can You Go?
When it comes to blood pressure, the lower, the better. "It doesn't really matter how low your reading is, even if it's something very, very low, like 85 systolic. As long as you're not feeling any ill effects from it, that's just fine. In fact, you should feel good knowing you're in a low-risk group," says Robert DiBianco, M.D., director of cardiology research at the Washington Adventist Hospital in Takoma Park, Maryland. The landmark Framingham Heart Study, which took a decades-long look at the health of more than 5,200 residents of Framingham, Massachusetts, found that people with systolic blood pressure readings below 120 mm Hg (millimeters of mercury) had the least chance of suffering heart attacks. The risk rose steadily with increased pressure. People with the highest readings, 170 mm Hg or above, were more than three times more likely to die of heart attacks than those at or below 120 mm Hg. Still, there are a couple of problems to watch for with low blood pressure. As people age, they're more likely to suffer from a form of temporary low blood pressure called orthostatic hypotension--the sensation you get when you hop out of bed and suddenly feel weak, like the room is spinning or the lights are dimmed. "If you have ever fainted from that, or if it happens more than very, very rarely, you should see a doctor," Dr. DiBianco says. The problem could be caused by mild dehydration, a reaction to medication, fever, illness or heat exhaustion, he says. For some people, especially the elderly and people with diabetes or heart disease and possibly those being treated for high blood pressure, readings that fall too low may be a particular risk. If you fit in one of these groups, consult your doctor, Dr. DiBianco says. |
Easing the Pressure
Lots of prescription drugs help reduce high blood pressure. Diuretics flush excess fluids from the body. Beta-blockers reduce the heart rate and the heart's total output of blood. Vasodilators widen arteries and allow easier blood flow. Sympathetic nerve inhibitors also prevent blood vessels from constricting.
But drugs should be a last resort. They can cause fatigue and inhibit your sex life, among other problems. The trick is to avoid high blood pressure in the first place--and the tips below will get you started. Even if you already have mild high blood pressure, the advice could reduce your dependence on drugs and maybe even let you control things naturally.
Have it tested. There's only one way to know for sure if you have high blood pressure: Have your doctor check your blood pressure. Once a year should be sufficient, unless your doctor orders more tests. It's a quick, painless procedure. The doctor puts an inflatable cuff around your arm and checks your pulse with a stethoscope. If you show a borderline high reading, the doctor may order several retests over a couple of weeks or months.
You can even find do-it-yourself blood pressure monitors in pharmacies, grocery stores and shopping malls. These can give you a rough estimate of your blood pressure, but Dr. Mulrow warns that the machines aren't a substitute for an annual doctor's visit. Some machines are not well calibrated and provide grossly inaccurate results. Too many external factors--have you been walking, or are you wearing a thick sleeve?--can interfere.
Lighten up. If you're overweight, even moderate weight loss may help lower your blood pressure, says Marvin Moser, M.D., clinical professor of medicine at Yale University School of Medicine in New Haven, Connecticut, and senior adviser to the National High Blood Pressure Education Program. In some cases, he says, weight loss of 10 to 15 pounds may be enough to lower slightly elevated blood pressure to normal and help you avoid medication.
A nationwide study of 162 overweight women, ages 30 to 54, showed how well weight loss can work. Over a 12-month period, the women on a weight loss program lost an average of six pounds. Their systolic readings fell an average of 3.7 points, while diastolic readings fell 4.1 points.
Move it. Exercise, combined with a low-fat diet, is the best way to lose weight and keep your arteries clog-free. Research shows that people who don't exercise are 35 to 50 percent more likely to develop high blood pressure. And the American College of Sports Medicine says that regular aerobic training can reduce systolic and diastolic blood pressure by as much as ten points.
You don't have to be a marathon runner to reap the benefits, either. In fact, some studies have found that lower-intensity workouts such as walking are as good or better at lowering blood pressure than running or other heavy-duty aerobic activities. Many experts recommend working out at least three times a week for 20 minutes a pop.
Shake it off. Remember that not everyone is sensitive to the effects of sodium. But until doctors can reliably tell who is or isn't, it's a good idea to limit your intake. "It certainly isn't going to hurt anyone to cut down on salt and probably will be of real value if you're successful," Dr. DiBianco says.
Cut salt from your diet wherever you can. Most of us are eating about 21/2 times more than we should. Swearing off the table shaker will have some effect. But research shows that three-fourths of all the salt we eat comes from processed foods such as cheese, soup, bread, baked goods and snacks.
"You have to read labels," Dr. Mulrow says. Check for sodium content, and shoot for a daily total of about 2,400 milligrams. When shopping, look for labels that say "low sodium." That means they contain no more than 140 milligrams of sodium per serving. And spend some extra time in the produce aisle. Almost every fruit and vegetable is naturally low in sodium.
Be careful when you eat out, too. You'll be surprised how fast sodium can add up. A hamburger from your favorite fast-food restaurant, for instance, may give you almost half a day's total.
Pile on the potassium. Studies have shown that eating 3,500 milligrams of potassium can help counteract sodium and keep blood volume--and blood pressure--down. And it's easy to get enough. A baked potato packs 838 milligrams of potassium all by itself, and one cup of spinach has 800 milligrams. Other potassium-packed foods include bananas, orange juice, corn, cabbage and broccoli. Check with your doctor before taking potassium supplements. Too much may aggravate kidney problems.
Meet your magnesium needs. Researchers seem to have found a link between low magnesium intake and high blood pressure. But just how much magnesium you need to combat high blood pressure remains unclear. For now, Dr. DiBianco says, your best bet is to get the Recommended Dietary Allowance (RDA) of about 280 milligrams.
Unfortunately, America's intake of magnesium has been dropping for a century, since we started processing foods and robbing them of their trace elements. Good sources of magnesium include nuts, spinach, lima beans, peas and seafood. But don't overdo it by taking supplements; Dr. Mulrow says too much magnesium can give you a nasty case of diarrhea.
Keep up your calcium. The link between calcium intake and blood pressure is controversial. Some studies show that extra calcium can lower blood pressure, while others show that it has no effect.
But experts aren't yet convinced that large doses of calcium are going to help. Dr. Mulrow says getting the RDA of 800 milligrams per day--three eight-ounce glasses of skim milk provide more than enough--and keeping your other risk factors under control is the best advice for now. Other calcium sources include low-fat cheeses, canned salmon and other canned fish with bones. If you want to take calcium supplements, see your doctor, since too much calcium can cause other problems, such as kidney stones.
Fill up with fiber. A Swedish study of 32 people with mild high blood pressure found that taking a seven-gram tablet of fiber each day helps lower diastolic blood pressure by five points. No one is sure why; perhaps it's because of weight loss due to people being fuller and eating less or because they eat less sodium. Whatever the reason, seven extra grams of fiber is easy to find. There's almost that much in a bowl of high-fiber cereal.
Drink in moderation. "A little alcohol isn't going to hurt," Dr. Mulrow says. "But drinking every day, and drinking to excess, could mean trouble." For women fighting high blood pressure, three ounces of alcohol a week seems to be about the limit. A 12-year study of 1,643 women, with a mean age of 47, showed that both systolic and diastolic pressure readings begin to rise steadily after that. That means six 12-ounce beers, six 4-ounce glasses of wine or six cocktails containing 1 ounce of hard liquor a week.
Stop smoking. Smoking markedly increases your risk of developing a stroke or blood vessel damage from high blood pressure, says Dr. Mulrow. When you smoke, it encourages your body to deposit cholesterol within your coronary arteries. This decreases the size of your vessels and forces your heart to work harder. "Anyone with high blood pressure should stop smoking immediately," advises Dr. Mulrow.
