The effects of dietary patterns on quality of life: a substudy of the Dietary Approaches to Stop Hypertension trial

Abstract

Few studies have examined the effects of dietary changes, particularly modifications of whole dietary patterns, on quality of life. The Dietary Approaches to Stop Hypertension (DASH) trial compared the effects of 3 dietary patterns on blood pressure. In this substudy, we examined the effect of these diets on health-related quality of life. All DASH participants ate a control diet for 3 weeks and then were randomly assigned to continue the control diet, to a fruits and vegetables diet or to a combination diet for 8 weeks. The combination diet emphasized fruits, vegetables, and low-fat dairy products. It included whole grains, poultry, fish, and nuts, and was reduced in fats, red meat, sweets, and sugar-containing beverages. The control diet was similar to typical American intake; the fruits and vegetables diet was rich in fruits and vegetables but was otherwise similar to the control diet. Both the fruits and vegetables diet (P < .001) and the combination diet (P < .001) significantly lowered blood pressure. At the Duke University Medical Center, Durham, NC, site, participants completed the Medical Outcomes Study Short Form-36 questionnaire to assess their health-related quality of life at baseline and at the end of the dietary intervention. Eighty-three participants completed the questionnaires at both time points. In general, health-related quality of life improved in all treatment groups except for the control group in perceptions of change in health, which diminished. In the combination diet group all the subscales were improved or unchanged compared with baseline values. However, only the change in health score improved significantly (P < .05) as compared with that of the control diet group. When all the subscales were summed into a total score, the control diet was associated with mean improvement of 4.0%, the fruits and vegetables diet with 5.0%, and the combination diet with 5.9% from baseline. These data suggest that the fruits and vegetables diet and particularly the combination diet cannot only lower blood pressure, but may also improve the perception of health-related quality of life.