May 2009
Emily B. Levitan, ScD, Alicja Wolk, Dr. Med Sci, and Murray A. Mittleman, MD, Dr. PH

 

Abstract

Background:

The DASH diet effectively reduces blood pressure. In observational studies, the association between diets consistent with DASH and risk of coronary heart disease and stroke has been examined with varying results. We hypothesized that diets consistent with the DASH diet would be associated with lower incidence of heart failure (HF).

 

Methods:

We conducted a prospective, observational study of 36,019 participants in the Swedish Mammography Cohort who were 48-83 years old without baseline HF, diabetes, or myocardial infarction. Diet was measured using food-frequency questionnaires. We created a score to assess consistency with DASH by ranking the intake of DASH diet components and 3 additional scores based on food and nutrient guidelines. Cox models were used to calculate rate ratios of HF hospitalization or death determined through the Swedish inpatient and cause-of-death registers between January 1, 1998 and December 31, 2004.

 

Results:

Over 7 years, 443 women developed HF. Women in the top quartile of the DASH diet score based on ranking DASH diet components had a 37% lower rate of HF after adjustment for age, physical activity, energy intake, education, family history of myocardial infarction, cigarette smoking, postmenopausal hormone use, living alone, hypertension, high cholesterol, body mass index, and incident myocardial infarction. Rate ratios across quartiles were 1.00, 0.85 (95% CI 0.66-1.11), 0.69 (95% CI 0.54-0.88), and 0.63 (95% CI 0.48-0.81), p for trend <0.001. A similar pattern was seen with the guideline-based scores.

 

Conclusions:

In this population, diets consistent with DASH were associated with lower rates of HF.

 

Introduction

Although diet patterns and foods choices have been linked to risk factors for heart failure (HF), little is known about whether diet may help prevent or delay HF. A recent American Heart Association scientific statement stresses the importance of preventing HF through medical treatment and lifestyle interventions targeting HF risk factors, including the DASH diet.1 The DASH diet may contribute to prevention of some cases of HF because it effectively reduced blood pressure and LDL cholesterol in clinical trials.2-4 This diet featured high intakes of fruits, vegetables, low-fat dairy, and whole grains resulting in high potassium, magnesium, calcium, and fiber, moderately high protein, and low total and saturated fat consumption.5 The National Heart, Lung, and Blood Institute has made public recommendations on food and nutrient intake for the prevention and treatment of hypertension based on the DASH diet.6 However, trials of the diet have not been long enough to determine the overall effect on cardiovascular events.

In a recent observational study by Fung and colleagues, women with the highest values of a score designed to measure consistency with DASH had a 24% lower risk of coronary heart disease and a 18% lower risk of stroke.7 Using a different DASH score, Folsom and colleagues did not find statistically significant associations with cardiovascular events.8 However, women with diets most consistent with DASH had an 18% lower rate of death from coronary heart disease and a 14% lower rate of death from stroke, which is similar to the projected effect from the DASH trial.2, 8

We hypothesized that diets consistent with the DASH diet would be associated with lower rates of HF. We constructed 4 scores to assess consistency with DASH, 2 patterned on previously published scores,7, 8 a score based on food intake recommendations, and a score based on nutrient intake recommendations.6 We examined the associations between the DASH scores and incident HF in a population of middle-aged and older women.