“Black adults have the highest rates of high blood pressure in the United States, and, for reasons we don’t fully understand, it starts at a younger age and results in strokes, heart attacks, heart failure, chronic kidney disease, and other serious hypertension-related health problems occurring at an earlier age as well,” says the senior study author, Stephen Sidney, MD, MPH, a research scientist at the Kaiser Permanente Division of Research in Oakland, California. The new study focused on a particularly high risk group of 1,761 Black patients — people whose blood pressure remained high even when they took medication to lower it. All patients were randomly assigned to one of three groups: to continue with their usual medication on its own for 12 months, to combine it with additional medication monitoring, or to combine it with lifestyle coaching. Patients assigned to receive extra medication monitoring got frequent blood pressure checks and were often prescribed two or more antihypertensives to get their condition under control. With lifestyle coaching, patients had up to 16 phone sessions with a registered dietitian to help them follow the DASH (Dietary Approaches to Stop Hypertension)) diet, which emphasizes cooking with vegetable oils, eating nuts, fruits, vegetables, low-fat dairy products, whole grains, fish and poultry, and limiting red meat and added sugars and salt. “We know how to treat high blood pressure with medication, but there is also a huge role that behavior change can play in prevention and treatment,” Dr. Sidney says. “This study was a tremendous opportunity to see if we had an intervention that could change behaviors and get blood pressure under control.” At the start of the study, patients in all three groups had an average blood pressure reading of 151/85 millimeters of mercury (mmHg). The main goal of the trial was to see how many people could reduce their blood pressure to less than 140/90 mmHg, a healthy range, after one year of usual care, enhanced medication management, or lifestyle coaching. Roughly two-thirds of participants in each group achieved this blood pressure target after one year, and there were no statistically meaningful differences between the groups, the researchers reported on May 18 in JAMA Network Open. Over time, however, the advantage of lifestyle coaching became clear. After two years, 72 percent of those in the lifestyle coaching group had well-controlled blood pressure, compared with 66 percent on medication management and 61 percent who received only standard care. These differences persisted after four years, when 73 percent in the lifestyle coaching group had well-controlled blood pressure, compared with 67 percent on medication management and 65 percent on standard care. “We had hoped that a 12-month coaching program could help people learn how to start a healthy, low-salt eating plan,” says another author of the study, Mai N. Nguyen-Huynh, MD, the regional medical director for primary stroke at Kaiser Permanente Northern California. “What was really eye-opening was learning that after the one-year program ended, these patients continued to have better blood pressure control, perhaps by sticking with the lifestyle changes they had learned — even though we had no contact with them,” Dr. Nguyen-Huynh says.
Diet and Lifestyle Coaching More Successful if Tailored to a Person’s Cultural Traditions
Coaching may have appeared more beneficial as time went on at least in part because it takes a while for people to revamp their eating habits and embrace a new way of eating, Nguyen-Huynh adds. The lifestyle coaching may also have produced lasting benefits because it was tailored to the experiences of Black patients. “People need to see themselves reflected in the recipes, photographs, and other educational materials you provide for them to feel like this is something that is worth their time and that they will truly benefit from,” Nguyen-Huynh says. One limitation of the study was that researchers didn’t verify how closely participants adhered to the DASH diet or how they ate after the yearlong intervention ended. The study also wasn’t designed to assess how any specific changes in diet might have directly impacted blood pressure. Previous research has documented the effectiveness of the DASH diet for lowering blood pressure, however. An analysis published in Advances in Nutrition in April 2020 pooled results from 30 previous clinical trials of the DASH diet and found it reduced systolic blood pressure (the “top number” that shows how much pressure blood exerts against artery walls when the heart beats) by an average of 3.2 mmHg, and cut diastolic blood pressure (the “bottom number” that indicates the amount of pressure when the heart rests between beats) by 2.3 mmHg on average. The main problem with the DASH diet is that many people don’t follow it, even when they have high blood pressure. According to a paper published in the Journal of the American Medical Association in April 2017, only about 1 in 100 people follow all the recommendations of this diet. With lifestyle coaching tailored specifically to the cultural traditions and foods favored by Black patients, these study participants may have had an easier time adopting a DASH diet and sticking with it than if all the advice had been completely out of step with their lives, says Daniel Lackland, DrPH, a professor of epidemiology and neurology at the Medical University of South Carolina in Charleston, who wasn’t involved in the new study. The results underscore the importance of culturally competent care, Dr. Lackland says. “Lifestyle clearly has a high impact on blood pressure and can be tailored to the individual,” Lackland says. Particularly when patients don’t get optimal results with blood pressure medication, helping them see how new eating and exercise habits can fit into their lives can make a big difference. “It is the total package,” Lackland says. Even though many people can lower their blood pressure with medication, that doesn’t make pills a panacea, notes Nguyen-Huynh. “Lifestyle matters too — regular exercise, not smoking, and eating well are all important,” Nguyen-Huynh says. “We can’t do it all with a pill bottle.”
