Diet and Hypertension
What kind of diet will help me keep my blood pressure under control?
If you have hypertension, your doctor will most likely recommend that you cut back on salt, particularly if you're 40 or older. To find out whether your blood pressure will respond to a low-salt diet, try to get no more than 1,500 milligrams of sodium a day (just about the amount in one teaspoon of table salt) -- and much less than what most people get. That includes the amount that is naturally in food as well as salt that has been added.
If your blood pressure doesn't go down after two months, you probably aren't salt-sensitive and will need to find other ways to lower it.
How can I cut back on salt without losing out on taste?
Try substituting herbs, spices, lemon juice, onion or garlic powders (not salts), or salt-free seasoning blends. Low-salt cookbooks can give you tips on how to make tasty meals with less salt. Be aware that most of the salt you eat is in processed foods such as frozen dinners, dried soups, canned foods, fast foods, and lunch meats. Try buying these convenience products in low-salt versions. When you eat out, stay away from dishes that contain soy sauce or monosodium glutamate (MSG), and ask for low-salt menu options. Also try dried or fresh fruit or graham crackers instead of salty snacks like pretzels and potato chips.
What's this blood-pressure-reducing diet I've been hearing about?
The DASH diet is named after a study called Dietary Approaches to Stop Hypertension, which found that eating a certain way can help people with mild hypertension bring their blood pressure down. Researchers from Johns Hopkins and other institutions tested three different meal plans on 459 people with mildly elevated blood pressure: a typical American diet; a typical American diet with extra fruits and vegetables; and a diet rich in fruits, vegetables, and low-fat dairy products and low in saturated fats (the DASH diet).
Everyone in the study took in 3,000 mg of sodium per day -- about 1,000 mg less than the average American gets, but still more than the recommended amount (2,300 mg). After eight weeks, those on the DASH diet showed the biggest improvement in blood pressure. Scientists believe this effect was due to the combination of foods in the regimen, rather than to any single nutrient. (The government now recommends that people at risk of hypertension consume no more than 1,500 mg of salt a day.)
How can I make my diet more like the DASH diet?
For the average-size person, the DASH diet recommends six to eight servings of grains; four to five servings of vegetables; four to five servings of fruits; two to three servings of low-fat or nonfat dairy products; and no more than six ounces of meat, poultry, or fish a day. The diet also calls for four to five servings of nuts, seeds, and legumes each week, and for limited amounts of fats and sweets.
The fats you eat should provide less than 30 percent of your total calories -- with fewer than 10 percent coming from saturated fats (the American Heart Association recommends keeping saturated fats below 7 percent of your total calories). Participants in the DASH study consumed only 27 percent of their calories from fat. Try to make changes in your diet slowly, so that you're likelier to stick with them.
Start by adding just one more serving of fruits and vegetables per day. A serving of meat should be no bigger than a deck of cards. If you're used to having meat at every meal, try working a few vegetarian meals into your week instead, and eat more casseroles, pasta, and stir-fry dishes, which tend to include less meat.
What else can I do?
One of the best moves you can make is to add more potassium to your diet, especially if you're taking diuretics to lower your blood pressure. (These drugs make it harder for your body to hold onto potassium.) Large amounts of this mineral seem to reduce blood pressure, while low levels may lead to hypertension.
On the DASH diet you should get 4,700 mg of potassium a day from food. That's a lot -- about what you'd get from 10 medium bananas. But it shouldn't be too hard to manage if you're following the DASH diet and eating a variety of fruits and vegetables. Potatoes, avocados, tomatoes, soybeans, apricots, citrus fruits, yogurt, and tuna are also good sources of potassium. (Check with your doctor before increasing your intake of the mineral if you have kidney problems.)
You should also try to keep excess weight off. Meet with a dietitian to plot out your calorie needs, and stay physically active. Losing weight should help lower your blood pressure. Finally, don't smoke, limit your alcohol intake to one drink a day if you're a women or two drinks a day at most if you're a man (hypertension is twice as high in heavy drinkers compared to light drinkers), reduce the amount of stress you're under, and get plenty of sleep.
National Heart, Lung, and Blood Institute. Your Guide to Lowering Your Blood Pressure With DASH.
U. S. Department of Agriculture. https://health.gov/dietaryguidelines/2015/guidelines/
New recommendations for treating patients with high blood pressure and cardiovascular disease. American Heart Association, March 31, 2015. http://newsroom.heart.org/news/new-recommendations-for-treating-patients-with-high-blood-pressure-and-cardiovascular-disease
Ornish D., et al. Intensive Lifestyle Changes for Reversal of Coronary Heart Disease. Journal of the American Medical Association 280(23):2001-2007
American Heart Association. Step I and Step II diets
National Institutes of Health. New Recommendations to Prevent High Blood Pressure by the National High Blood Pressure Education Program. http://www.nih.gov/news/pr/oct2002/nhlbi-15.htm
National Heart, Lung, and Blood Institute. Your Guide to Lowering Your Blood Pressure With DASH How Do I Make the DASH? http://www.nhlbi.nih.gov/health/public/heart/hbp/dash/how_make_dash.html