Are you among the 50 million adults who have high blood pressure? Do you know for sure? One in four people have high blood pressure, also known as hypertension, and another two in four have blood pressure levels that, though not technically considered “high,” are still high enough to significantly increase their risk of heart disease and stroke, the No. 1 and No. 2 killers in the United States. The problem is, most people don’t know that they have it. That’s because it has no symptoms.
Who gets it?
Every ethnic group is susceptible to developing high blood pressure, but African-Americans tend to develop it earlier and more often. High blood pressure becomes more common as people age; about half of all people older than 60 have it.
Many people don’t find out that they have high blood pressure until they have a heart attack or stroke. Twenty-five percent die without ever being diagnosed.
By the time you are diagnosed with high blood pressure, it can have already wreaked havoc on your heart, kidneys and brain. Once developed, high blood pressure lasts a lifetime and must be monitored and treated.
A simple plan
For years, researchers investigated the effect of different nutrients on blood pressure, mainly using pills. The findings were not conclusive.
In the mid-1990s, the National Heart, Lung, and Blood Institute began a study called DASH, or Dietary Approaches to Stop Hypertension. DASH focused on the effects of an overall diet.
“People eat food, not nutrients,” says Dr. Marlene Most-Windhauser, a dietitian and professor of research at Pennington Biomedical Laboratory in Baton Rouge, La., and one of the investigators involved with DASH. “So it made sense to look at the diet as a whole and include foods particularly high in nutrients like calcium, magnesium, potassium, fiber– those we thought might have a relationship to blood pressure.”
The study of 459 adults included both men and women who had high blood pressure. Sixty percent of the study participants were black. Over an eight-week period, participants ate one of three different eating plans: A diet much like the ones Americans currently eat; That same diet, but with increased servings of fruits and vegetables; The DASH diet, low in saturated fat, total fat and cholesterol with 8 to 10 servings of fruits and vegetables, as well as 2 to 3 servings of low-fat dairy foods a day.
All three plans averaged 3,000 milligrams of sodium–about 20 percent less than Americans currently consume. The results surprised even some of the researchers.
“We saw drops in blood pressure normally only seen in people on antihypertensive medications,” Most-Windhauser says. Both the increased fruit and veggie combo and the DASH plan reduced blood pressure, but the DASH plan had the greatest effect, providing an average reduction of 6-11 mm Hg (or “millimeters of mercury,” the unit of measurement for blood pressure) for systolic and 3-6 mm Hg for diastolic blood pressures.
“Results came very quickly, about two weeks after starting the diet,” Most-Windhauser says.
Despite this DASH diet’s tremendous effects, one question still remained: What would happen to blood pressure levels if the amount of sodium were lowered in the DASH diet?
The debate over sodium’s role in hypertension had been raging for years. So researchers began “DASH-Sodium” to see whether they could lower blood pressure even more.
Over a 12-week period, participants ate either a DASH diet or a normal diet. Every four weeks, the sodium content was changed to one of three levels: a higher intake of 3,300 milligrams, an intermediate intake of 2,400 mg or a lower intake of 1,500 mg. Forty percent of the 412 participants in the study had hypertension, and 60 percent had normal or high-normal blood pressures.
Once again, DASH delivered good news. The study, published in January in the New England Journal of Medicine, showed that on both the DASH and the usual diets, lower sodium intakes meant lower blood pressure levels. But the DASH diet combined with the lowest sodium intake was the clear winner, almost doubling the effects of the DASH diet alone. Systolic blood pressure was reduced by an average of 8.9 mm Hg to 11.5 mm Hg and diastolic was reduced about 4.5 to 7.1 mm Hg. As researchers suspected, people with hypertension had greater decreases in blood pressure levels than those without hypertension.
Following DASH
“Jumping to eight to ten servings of fruits and vegetables each day can be a challenge, especially considering most people are only eating two and a half servings now. Most-Windhauser says.
Cutting back on sodium also takes practice. “Research shows that you can train your taste buds to adapt and eventually your desire for salty foods will decrease.” Most-Windhauser says.
Some tips:
– Make gradual changes. Add one additional serving of fruits or vegetables to your diet each week, or replace salty snacks like chips with reduced sodium versions.
– Put carbohydrates at center stage on your dinner plate: vegetables, pasta, beans and rice. Treat meat as a supporting player, not the main star.
– “Get your eight to ten servings of fruits and vegetables each day by planning two servings at each meal,” Most-Windhauser says. For breakfast, have a glass of grapefruit juice and sliced strawberries in your yogurt. For lunch, have a cup of low-sodium vegetable soup and some carrot sticks. Snack on apple wedges or dried apricots in the afternoon. Try a vegetable stir-fry for dinner and low-fat ice cream topped with pureed peaches and sprinkled with blueberries for dessert. Eight to ten servings is a lot, but keep portion sizes in mind: a medium size piece of fruit, 1/2 cup of chopped fresh, frozen or canned fruits or vegetables, and 6 ounces of juice all count as a serving.
– To get dairy to three servings per day, have one low-fat or fat-free serving at each meal. If you’re lactose intolerant, try lactase enzyme pills or drops with the dairy foods. Or buy lactose-free milk or milk with lactase enzyme.
– Choose whole-grain foods like 100 percent whole-wheat or whole-grain bread or cereals. Check labels to make sure you’re getting 100 percent whole grains.
– Use the percent daily value on food labels to compare products and choose those lowest in fat, cholesterol and sodium.
To reduce sodium intake, read labels. Buy sodium-free, low sodium or reduced sodium versions of processed foods. Use herbs and spices to season foods.
More information on the DASH diet, including recipes and eating tips, are available on two Web sites. The National Heart, Lung, and Blood Institute’s is at: www.nhlbi.nih.gov/hbp/consumer/hearthealth/eating.html.
The DASH Study is available at www.dash.bwh.harvard.edu/ or through the mail: Write to DASH Study, NHLBI Information Center, Box 30105, Bethesda, MD 20824-0105. Information on DASH-Sodium may not yet be included on the Web sites, so recipes may contain more sodium than used in that study.
Controlling high blood pressure
– Lose weight, if you’re overweight. If you’re at an ideal weight, avoid gaining extra pounds, especially as you age. Dropping even 10 pounds can make a big difference in blood pressure.
– Be physically active. Doing at least 30 minutes of aerobic exercise on most days can help you manage blood pressure. Try brisk walking, swimming, biking or running.
– Follow the DASH diet by including 8-10 servings of fruits and vegetables, two to three servings of low-fat dairy products, and keeping sodium down to no more than 2,400 mg/day and preferably to less than 1,500 mg.
– Limit alcohol drinks to no more than two servings a day for men, one serving for women.
– If your doctor prescribes medication to treat your high blood pressure, take it faithfully.
DASH in brief
The plan below is based on 2,000 calories a day. The number of daily servings in a food group may vary from those listed depending on your calorie needs.
FOOD: Grains
DAILY SERVINGS: 7-8
SERVING SIZES: 1 slice bread, 1 cup dry cereal, 1/2 cup cooked rice, pasta or cereal
FOOD: Vegetables
DAILY SERVINGS: 4-5
SERVING SIZES: 1 cup raw leafy vegetable, 1/2 cup cooked vegetable
FOOD: Fruits
DAILY SERVINGS: 4-5
SERVING SIZES: 6 oz. fruit juice,1 whole medium fruit, 1/4 cup dried fruit, 1/2 cup fresh, frozen, or canned fruit
FOOD: Low-fat or non-fat dairy
DAILY SERVINGS: 2-3
SERVING SIZES: 1 cup milk or yogurt, 1 1/2 ounces cheese
FOOD: Lean meat, poultry, fish
DAILY SERVINGS: 2 or fewer
SERVING SIZES: 3 ounces cooked
FOOD: Nuts, seeds, beans
DAILY SERVINGS: 4-5 per week
SERVING SIZES: 1/3 cup nuts, 2 tablespoons seeds, 1/2 cup cooked or canned beans
FOOD: Fats, oils, Dressings
DAILY SERVINGS: 2-3
SERVING SIZES: 1 teaspoon soft margarine, 1 tablespoon low-fat mayonnaise, 2 tablespoons light salad dressing, 1 teaspoon vegetable oil
FOOD: Snacks and Sweets
DAILY SERVINGS: 5 per week
SERVING SIZES: 1 tablespoon sugar, jelly or jam; 1/2 ounce jelly beans, 1 cup lemonade
