DASH Diet Reduces Risk of Heart Failure

May 15, 2009 (Boston, Massachusetts) — Women who had a food intake similar to the Dietary Approaches to Stop Hypertension (DASH) diet, with high consumption of fruits, vegetables, and whole grains and a low intake of fat and dairy products, had a reduced risk of developing heart failure in a recent study [1].

The DASH diet has been shown to reduce blood pressure, and observational studies have also suggested that it may reduce the risk of coronary heart disease and stroke. The current research, published in the May 11, 2009 issue of the Archives of Internal Medicine, looked at whether such a diet could also reduce the risk of heart failure in healthy women.

Researchers, led by Dr Emily Levitan (Beth Israel Deaconess Medical Center, Boston, MA), studied 36 019 women aged 48 to 83 years taking part in the Swedish Mammography Cohort. The women did not have heart failure, diabetes, or a history of MI at baseline. Diet was measured using food-frequency questionnaires. A score was created to assess consistency with the DASH diet, and heart-failure hospitalization or death was determined using the Swedish inpatient and cause-of-death registers.

Results showed that women in the top quartile of the DASH component score ate, on average, three servings of fruit, 3.5 servings of vegetables, 5.1 servings of whole grains, 1.6 servings of low-fat dairy products, 0.1 servings of sweetened beverages, and 0.8 servings of red or processed meat per day. In comparison, women in the bottom quartile of the score ate, on average, 1.4 servings of fruit, 1.8 servings of vegetables, 3.3 servings of whole grains, 0.6 servings of low-fat dairy products, 0.4 servings of sweetened beverages, and 1.3 servings of red or processed meat per day.

During the seven years of follow-up, 443 women developed heart failure. Women in the top quartile of the DASH diet score had a 37% lower rate of heart failure after adjustment for age, physical activity, energy intake, education status, family history of MI, cigarette smoking, postmenopausal hormone use, living alone, hypertension, high cholesterol concentration, body-mass index, and incident MI.

Adjusted Relative Risk of Heart Failure as Related to DASH Diet Score

Quartile 4 is top DASH scores and quartile 1 is bottom DASH scores

Levitan commented to heartwire : "This is the first time it has been shown that DASH diet is associated with a lower risk of developing heart failure. Previous studies have suggested a reduced risk of CHD and stroke. I think we can now say that the blood-pressure benefits known to occur from this diet do seem to translate into reduced cardiovascular events, including the development of heart failure."

She noted that, like this study, the heart-disease and stroke studies were also conducted in women, which is somewhat unusual for cardiac research, which tends to focus on men. "That was one of the reasons we wanted to focus on women," Levitan commented. "And heart failure is a major problem in older women. I would say the gender difference is less than something like MI. But we have a follow-up study planned in men," she added.

She pointed out that in the original DASH study, the diet was associated with a 5.5-mm-Hg reduction in blood pressure, which would have accounted for the reduction in heart failure seen in this study. But reducing lipids and other mechanisms may also play a role in the benefit seen.

And while only 20% of the women in this study had hypertension, Levitan believes that a reduction in blood pressure is still beneficial for those normal blood pressures. "We looked at people with raised blood pressure and those with normal pressures at baseline, and the DASH diet was protective in both groups. We think lower blood pressure is better in almost everyone until you get down to very low pressures. Even if you have a pressure of 125/90, it would probably be better if it were 115/80," she said. She added that the main goal of the DASH diet is to increase electrolytes such as calcium, which are thought to antagonize sodium, which is known to increase blood pressure.

"Our population did not have heart failure at baseline, but I would recommend patients with heart failure follow this diet. I would also say that this diet is a particularly healthy one to follow for everyone, but especially for those with blood-pressure issues," Levitan commented.

Hypertension the Most Common Condition for Which Women Sought Treatment

Approximately 25 million women in the US--most over the age of 45--were treated for high blood pressure in 2006, making it the most common condition for which women sought treatment, according to the latest "News and Numbers" from the Agency for Healthcare Research and Quality (AHRQ) [2]. The statistical analysis by the AHRQ found that the other most common diseases for which women aged over 45 sought treatment in 2006 included hyperlipidemia, heart disease, and diabetes.

In terms of expenditure, heart disease tops the table for both men and women.

Expenditure and Numbers Affected by Various Cardiovascular Conditions: US AHRQ Data for 2006

The data include treatment in doctors' offices and hospital outpatient clinics, emergency rooms, hospitals, and by home healthcare providers. This analysis was based on data from AHRQ's Medical Expenditure Panel Survey, which collects information each year from a nationally representative sample of the US civilian noninstitutionalized population about their healthcare use, expenses, access to services, health status, and the quality of the healthcare they obtained.

Heartwire from Medscape © 2009  Medscape, LLC

Cite this: DASH Diet Reduces Risk of Heart Failure - Medscape - May 16, 2009.