Leading Studies on Reducing Blood Pressure without Drugs
A growing number of clinical studies attest to the role of lifestyle changes in controlling and reducing blood pressure. From what you eat and how much you eat to how you cope with a traffic jam and how much exercise you get, lifestyle modifications can do as much if not more than medication to lower blood pressure.
Here are seven major studies that provide proof that a healthy lifestyle lowers blood pressure:
Framingham Heart Study. The grandfather of all population-based studies, this research began in 1948 when scientists from the U.S. Public Health Service chose the town of Framingham, Massachusetts, and its residents to help them learn more about the growing epidemic of heart disease. Results from Framingham have proven the connection between hypertension and heart disease, exercise and hypertension, diet and heart disease, and diabetes and heart disease, among others.
Dietary Approaches to Stop Hypertension (DASH). This study, published in the New England Journal of Medicine in 1997, evaluated 459 middle-aged Americans with and without high blood pressure as they followed one of three diets: the typical American diet, one that included more fruits and vegetables than the typical American diet, or the DASH diet, an eating program specifically designed to be high in those nutrients found to positively affect blood pressure and low in those found to negatively affect it. A later study, the DASH-sodium study, coupled the DASH diet with reduced sodium intake and found an even greater drop in blood pressure.
Nurses’ Health Study. This long-term, ongoing study evaluates the health and lifestyle habits of 82,473 U.S. nurses. A major finding of the study was that each 2.2 pounds of weight gain after age 18 increased a woman’s risk of hypertension by 5 percent. This risk increase occurred even if a woman’s weight remained in the so-called normal range, generally defined as a body mass index (BMI) of less than 25. Conversely, a group of studies finds that losing 4 to 8 percent of body weight results in at least a 3/3 mmHg drop in blood pressure and less need for medication.
TOMHS. The best currently available data on combined dietary intervention comes from the Treatment of Mild Hypertension Study (TOMHS), in which 902 patients with mild diastolic hypertension (90 to 100 mmHg) followed a program to lose weight, restrict sodium and alcohol, and increase physical activity. Then they received either placebos (dummy pills) or one of five different antihypertensive drugs. All improved their blood pressure, with the group on placebos maintaining an average 8.6/8.6 mmHg blood pressure reduction four years after the trial ended. Plus, their levels of “bad” cholesterol dropped, and their levels of “good” cholesterol rose, reducing their overall cardiovascular risk.
Trials of Hypertension Prevention, Phase II. This study focused on 2,382 men and women, ages 30 to 54, who had blood pressures less than 140/83-89 mmHg and who were 110 to 165 percent of their ideal body weight. All were given the same medical treatment, and then were split into four groups. The first received no extra guidance, the second reduced their salt intake, the third began a weight-loss program, and the fourth both cut back on salt and lost weight. Compared with those receiving just typical care, those who reduced sodium intake saw their blood pressures fall an average of 2.9/1.6 mmHg, those who lost weight saw average reductions of 3.7/2.7 mmHg, and those on the combined therapy had the greatest reduction: 4.0/2.0 mmHg. Four years after the study ended, those who received the interventions were less likely to have progressed to true hypertension than those who received only medication.
TONE Study. The Trial of Nonpharmacologic Interventions in the Elderly (TONE), was the first multicenter clinical trial of sufficient size and duration (30 months) to show that lifestyle modifications can be used to control high blood pressure in older people. The first results from this trial, published in the Journal of the American Medical Association in March 1998, found that losing weight and cutting down on salt could lessen and even eliminate the need for blood pressure-lowering medications in the elderly.
PREMIER Clinical Trial. This was the first clinical trial to put together everything we know about lifestyle changes and blood pressure to see how the different changes interacted with one another to reduce blood pressure. Supported by the National Heart, Lung, and Blood Institute, this study compared the effects of two behavioral interventions on blood pressure in
810 adults who had high blood pressure but were not taking antihypertensive medications.
At the start of the trial, 38 percent of participants were diagnosed as hypertensive, and most were overweight and got little physical activity. Participants either received advice only (typically from a dietitian), implemented established recommendations (quitting smoking, losing weight, increasing exercise) for lowering blood pressure, or combined established recommendations with the DASH diet. After six months, participants in both interventional groups lost weight, improved their fitness, lowered their sodium intake, and reduced their blood pressure. The group following established guidelines reduced their systolic blood pressure by an average of 3.7 mmHg, while those who also followed the DASH diet had reductions of 4.3 mmHg.
By the end of the study, 26 percent of those in the advice-only group still had hypertension, compared with just 17 percent who followed the established guidelines and 12 percent who also used the DASH diet.