Halting Hypertension With a Healthy Diet
Last reviewed by Faculty of Harvard Medical School on January 16, 2013
By Linda Antinoro, R.D., L.D.N., J.D., C.D.E.
Hypertension (high blood pressure) is often dubbed the "silent killer" because you can have no symptoms while your risks of stroke, heart attack and kidney failure escalate. To help prevent hypertension and its adverse consequences, a new category called "prehypertension" was created. It is defined by readings of 120/80 to 139/89. By adopting healthy habits, particularly eating right, you will help to stop prehypertension from moving to the next stage.
The decision to highlight prehypertension was based on numerous studies showing that damage to arteries can begin at blood pressure levels as low as 120/80 previously considered normal. In other words, if your upper blood-pressure number (systolic) is between 120 and 139 or your lower number (diastolic) is 80 to 89 then you are prehypertensive. Most people with prehypertension do not require medication, but all can benefit from the following dietary recommendations:
Being overweight is a major factor for developing high blood pressure. And weight loss can sometimes dramatically improve blood pressure readings. In a study called the trials of Hypertension Prevention, overweight people who lost and maintained at least 10 pounds saw notable reductions in blood pressure, and fewer of them were ultimately diagnosed with high blood pressure. Aiming for a body mass index (BMI) of under 25 is ideal.
Dine With DASH
An eating pattern popularly referred to as DASH (Dietary Approaches to Stop Hypertension) has proven effective in managing hypertension. This dietary pattern, derived from the landmark DASH study conducted a few years back, has shown average blood pressure reductions of nearly 6 points systolic and 3 points diastolic. Blood pressures fell regardless of gender, race and level of elevated blood pressure. Since the DASH diet lowered blood pressure whether or not blood pressure was elevated to start, many experts now believe this eating style should be followed by anyone who is prehypertensive. Doing the DASH diet means eating plenty of fruits, vegetables, whole grains and low-fat dairy products; some fish, poultry, dried beans, nuts and seeds; and minimal red meat, sweets and sugar-laden beverages.
The mix of food selections in DASH provides ample calcium, potassium, magnesium, vitamin C and fiber, plus limits saturated fat, cholesterol and sodium. Lowering sodium to 1,500 milligrams a day works the best on blood pressure, according to study results from DASH-Sodium a follow up to the original DASH study. It cut blood pressure by nearly 9 points systolic and over 5 points diastolic.
The Institute of Medicine recommends different levels of sodium intake based on age: a daily sodium intake of 1,500 milligrams for young and middle-age adults; 1,300 milligrams for those over age 50; and 1,200 milligrams for individuals over the age of 70.
Limiting sodium to 1,500 milligrams or less per day is tough. A more realistic sodium limit of 2,300 milligrams combined with the other elements of a DASH diet will still lower blood pressure, but not as much. Current average daily sodium consumption for American men is 3,100 to 4,700 milligrams and for women 2,300 to 3,100 milligrams. There is no downside to lowering sodium intake to 1,500 to 2,300 milligrams per day. To help make the change, skip the saltshaker. Rely on other seasonings besides salt, and pare down use of processed foods. Sodium in processed, convenience and restaurant foods supply approximately 75% of our sodium intake.
The DASH diet also is in sync with another of the Institute's recommendations to eat more potassium, a mineral linked with lower blood pressure. Upping potassium intake to 4,600 milligrams a day should be the goal, except for people with poorly functioning kidneys. This is double the amount most people currently consume. Potent potassium sources include dried apricots, banana, honeydew melon, sweet potato, tomatoes, peanuts, orange juice and milk.
How does the DASH diet deliver its results? In the past, studies have investigated many of the same nutrients present in the DASH diet individually to gauge their effect on hindering hypertension. Typically consumed as dietary supplements, results of individual ingredients were unimpressive or inconclusive. It seems that the various nutrients of DASH, as they occur together in food, work in concert to lower blood pressure. And eating a DASH-style diet is a much tastier option than popping a plethora of individual supplement pills. See the summary of the DASH eating style below.
Heavy alcohol use increases your risk of high blood pressure. If you drink alcohol, have no more than two drinks a day for men, and only one a day for women. One drink is equivalent to 12 ounces of beer, 5 ounces of wine or 1½ ounces of liquor.
The Bottom Line
Adopting an overall healthy lifestyle that also includes staying active, managing stress and not smoking affords you the best chance of reducing your risk of developing high blood pressure. There are no guarantees, but eating right can go a long way toward keeping hypertension at bay.
Linda Antinoro, R.D., L.D.N., J.D., C.D.E., is a senior nutritionist at Brigham and Women's Hospital. She is also a certified diabetes educator and counsels patients at the Nutrition Consultation Service.