DASH: a diet for all diseases.

Don't have high blood pressure? Don't assume you never will.

One out of four American adults does. Among people 60 or over, it's one out of two (see "Older and Higher").

But that doesn't mean everyone else is in the clear.

Say your doctor says that your blood pressure is "high-normal," or even "normal." Sounds good, huh?

Not so good.

Even so-called normal blood pressure raises the risk of heart disease and stroke. What you want is "optimal" blood pressure (see "What's Your Risk?"). Less than half of all Americans have it... and most of them are young.

How can you keep your blood pressure from creeping up from optimal to normal to high?

For years, experts have recommended four proven strategies. The Big Four: cut back on salt; lose excess weight; exercise; and, if you drink, limit alcoholic beverages to two drinks a day.

Now we can make it the Big Five. A landmark study called DASH--Dietary Approaches to Stop Hypertension--shows that eating the right foods also works. It can lower blood pressure as much as taking a drug.

Better yet: It's the same diet that may help cut your risk of cancer, heart disease, osteoporosis, and diabetes.

Designing DASH

For years, researchers were stumped.

"In the 1970s, we found that blood pressures were lower in vegetarians, who eat little or no fat and cholesterol and lots of fruits, vegetables, and grains rich in potassium, magnesium, and fiber," says Frank Sacks, a researcher at Harvard Medical School who helped create the DASH study.

Other studies showed that people who ate more protein also had lower blood pressure. And some scientists argued that calcium played a role as well.

But when researchers gave people calcium or magnesium supplements, blood pressures barely budged.

"In the Trials of Hypertension Prevention, the only thing that lowered blood pressure was cutting back on salt and reducing overweight," says Jeremiah Stamler, professor emeritus at Northwestern University Medical School in Chicago, who also helped design DASH.

"The scientific literature was confusing," says Lawrence J. Appel, a DASH researcher at Johns Hopkins University in Baltimore. So they constructed a diet to provide all of the promising nutrients.

"We decided to test the whole diet, not supplements," says Sacks.

Researchers enrolled 459 adults at four centers around the country.(1) Less than a third already had hypertension. The rest had normal or high-normal blood pressure--that is, diastolic pressure between 80 and 89. ("Diastolic" is the lower of the two blood pressure numbers.)

For eight weeks, people were randomly assigned to one of three diets:

* The "control" diet had levels of fat and cholesterol that matched the average American's diet. and lower-than-average levels of potassium, magnesium, and calcium.

* The "fruit and vegetable" diet matched the control diet in fat, saturated fat, cholesterol, and protein. The only difference: Potassium, magnesium, and fiber got a boost when fruits and vegetables replaced some snacks and sweets.

* The "combination" diet had less total fat, saturated fat, and cholesterol than the fruit and vegetable diet or the control diet (see "Count the Nutrients"). It was rich in fruits, vegetables, and low-fat dairy products (which upped the potassium, magnesium, calcium, fiber, and protein).

"We kept the salt constant in all three diets at 3,000 mg a day," says Appel. (That's slightly less than the average American's 3,600 to 4,000 mg a day, but more than the 2,400 mg health experts recommend.) Ditto for other things known to influence blood pressure: Calories were the same for all three diets (so no one would gain or lose weight) and alcohol was limited to a drink or two a week.

The researchers didn't have to wait long.

The Winner

"Blood pressure fell within days," says Appel. The fruit and vegetable diet lowered pressure significantly. But the combination diet won hands down. It lowered average pressures by:

* 3.5 points (systolic) over 2.1 points (diastolic) in those with normal or high-normal blood pressure, and

* 11.4 points over 5.5 points in those with high blood pressure.

"That's about what you'd get in people given a drug," says Appel.

Why such success when supplements of calcium, magnesium, and other individual nutrients flopped in earlier studies?

"Maybe you need to eat the nutrients together because the effect of each one is small," says Eva Obarzanek, a DASH co-author at the National Heart, Lung and Blood Institute in Bethesda, Maryland. "Or maybe the foods improve the absorption of the nutrients."

It's also possible that something else in fruits, vegetables, and low-fat dairy products lowers blood pressure. The DASH can't say. Nor can it say which nutrients made the difference.

But it said enough.

"Now we have everything we need to know to end the epidemic rise in blood pressure with age--and high blood pressure--in this country," says Jeremiah Stamler.

"We've known how to lower blood cholesterol since 1960. Now we know the same about blood pressure. So we can prevent both major diet-related risk factors for heart disease and stroke."

DASH-2 is already under way. It will test the combination diet at three levels of sodium intake: 3,450 ma, 2,300 ma, and 1,650 mg a day. "We want to see what bang you get for your buck when you combine the DASH diet with less salt," says Appel.

And who knows? Maybe someday, someone will compare the DASH diet to those recommended by Nathan Pritikin and Dean Ornish to see if their advice--to cut fats and cholesterol even further, use only whole grains, and add little or no sugar--yields even greater benefits.

But you needn't wait. Adding the DASH diet to the Big Four (see "The Bottom Line") is easy to follow, inexpensive, and not too strict.

"The beauty of DASH is that it doesn't take a genius to follow," says Norman Kaplan, a hypertension expert at the University of Texas Health Sciences Center in Dallas. "You just cut the fat, double your fruits and vegetables, and use low-fat dairy products."

What's more, the DASH has everything: fruits and vegetables to cut your risk of cancer, calcium to lower your risk of osteoporosis, and limits on saturated fat and cholesterol to cut your risk of heart disease.

"It's not a diet for one disease," says Appel. "It's a diet for all diseases."

RELATED ARTICLE: COUNT THE NUTRIENTS

The DASH "Combination Diet" is low in cholesterol, high in fiber, potassium, calcium, and magnesium, and moderately high in protein. Here's how it compares with the DASH "Control Diet," which is closer to what the typical American eats. (Both diets supply 2,000 calories a day.)

                                       DASH           DASH
Nutrient                              Combination    Control
                                       Diet           Diet

Fat (% of cals.)                        27             37
  Saturated fat (% of cals.)             6             16
  Monounsaturated fat (% of cals.)      13             13
  Polyunsaturated fat (% of cals.)       8              8
Carbohydrates (% of cals.)              55             48
Protein (% of cals.)                    18             15
Cholesterol (mg per day)               150            300
Fiber (grams per day)                    3              9
Potassium (mg per day)               4,700          1,700
Magnesium (mg per day)                 500            165
Calcium (mg per day)                 1,240            450
Sodium (mg per day)                  3,000          3,000

Source: DASH clinical study.

RELATED ARTICLE: THE BOTTOM LINE

If your blood pressure is optimal, following all of these Big Five proven strategies will help keep it from climbing as you get older. If your blood pressure is normal or high-normal, the Big Five may help lower it. if your blood pressure is high, the Big Five may enable you to use less--or get off--medication.

1. Lose weight if you're overweight. Dropping as few as ten pounds can make a difference.

2. Cut sodium to less than about 2,400 mg a day. Check labels for the lowest-sodium brands. Limit foods with 480 mg of sodium or more per serving. That's 20 percent of the Daily Value.

3. Walk briskly, jog, swim, cycle, or do other aerobic exercise for 30 to 45 minutes a day at least three times a week.

4. If you drink, keep it to no more than two servings of beer, wine, or liquor a day to keep blood pressure from rising. Women should limit themselves to one drink a day. Consuming more may increase the risk of breast cancer.

5. Try a DASH-like diet. It should help reduce your risk of heart disease, stroke, cancer, osteoporosis, and diabetes.

RELATED ARTICLE: The DASH Diet

It's not tough to follow the DASH diet. "Almost 100 percent of the participants completed the study," says researcher Lawrence J. Appel. Granted, when it came to food, all they had to do was eat. The researchers did all the planning, shopping, and cooking. Still, the foods weren't unusual--no specialty foods with fat substitutes, nothing you couldn't buy at a local supermarket. (For detailed information about the DASH study, the results, and the diet, see the DASH's World Wide Web home page-dash.bwh.harvard.edu.)

Here's how many servings of which kinds of foods were in the DASH study's 2,000-calorie-a-day "Combination Diet"--the one that lowered blood pressure the most.

Food & Servings                       Examples of 1 Serving

Grains & grain products                1 slice bread
7 to 8 a day                           1/2 cup dry cereal
                                       1/2 cup cooked rice,
                                       pasta, or cereal

Vegetables                             1 cup raw leafy vegetable
4 to 5 a day                           1/2 cup cooked vegetable
                                       3/4 cup vegetable juice

Fruits                                 3/4 cup fruit juice
4 to 5 a day                           1 medium fruit
                                       1/4 cup dried fruit
                                       1/2 cup fresh, frozen,
                                       or canned fruit

Low-fat or non-fat dairy               1 cup skim or 1% milk
foods 2 to 3 a ay                      1 cup low-fat yogurt
                                       1 1/2 oz. part-skim
                                       or non-fat cheese

Meats, poultry, &                      3 oz. broiled or
fish 2 or less a day                   roasted lean meats,
                                       skinless poultry, or fish

Nuts, seeds, &                         1/3 cup nuts
beans 4 to 5 a week                    2 Tbs. sunflower seeds
                                       1/2 cup cooked beans

Added fats, oils, & salad dressings    1 tsp. oil or soft margarine
2 to 3 a day                           1 tsp. regular mayonnaise
                                       1 Tbs. Iow-fat mayonnaise
                                       1 Tbs. regular salad dressing
                                       2 Tbs. Iight salad dressing

Snacks & sweets                        1 medium fruit
5 a week                               1 cup low-fat yogurt
                                       1/2 cup low-fat frozen yogurt
                                       3/4 cup pretzels
                                       1 Tbs. maple syrup, sugar,
                                       jelly, or jam
                                       1/2  cup Jell-O
                                       3 pieces hard candy
                                       15 jellybeans

Food & Servings                        Our Comments

Grains & grain products                Seven or eight servings a
7 to 8 a day                           day seem like a
                                       lot, but they're small.

Vegetables                             Eight to ten servings a
4 to 5 a day                           day tops the five to
                                       nine servings recommended
                                       by the National
                                       Cancer Institute's "5 a Day"
                                       program. The average
                                       American is stuck at
                                       just over three.

Fruits                                 Three servings a day
4 to 5 a day                           is better to help
                                       reduce the risk of
Low-fat or non-fat dairy               osteoporosis.
foods 2 to 3 a ay

Meats, poultry, &                      We now average more
fish 2 or less a day                   than two servings a
                                       day, and they're often
                                       fatty: hamburgers,
                                       fried chicken or fish,
                                      or chicken with the skin.

Nuts, seeds, &                         Most people eat only two
beans 4 to 5 a week                    servings of beans
                                       a week. They're missing
                                       out on delicious
                                       lentil soups, Cuban
                                       black-beans-and-rice,
                                       Middle Eastern hummus,
                                       Mexican bean
                                       burritos, etc.

Added fats, oils, & salad dressings    The "control" diet had
2 to 3 a day                           six servings a day.
                                       Add your fats to vegetables,
                                       beans, breads,
                                       or other foods for flavor.

Snacks & sweets                        The healthier, the better.
5 a week                               If you're more
                                       likely to go for the
                                       jellybeans than the fresh
                                       fruit, keeping your snacks
                                       to less than one
                                       a day minimizes the damage.
                                       The "control" diet had
                                       four snacks a day.

Source: DASH clinical study.

(1) New England Journal of Medicine 336: 1117, 1997.