DASH for better blood pressure control

In today’s US, 46% of adults have hypertension (high blood pressure based on current diagnostic criterion)1.  Everyday at our primary care clinic, we give hypertension patients advice on healthy diet and lifestyle.  However, so often I see the puzzled expression in a patient’s face or I get asked directly: but where shall I start?  This is a brief summary of DASH diet, which has shown benefits in controlling blood pressure and reducing risk of other diseases such as strokes and cancers.

What is DASH diet?

DASH (Dietary Approaches to Stop Hypertension) was first formulated and tested in a clinical trial that was published in 19972.  This study tested the effects of DASH diet on blood pressure control.  DASH features a diet that is rich in fruits, vegetables, legumens (such as beans, peas and lentils) and low-fat dairy products, and is low in simple sugar, red meats and saturated fat.  More specifically, it includes four to five servings of fruit, four to five servings of vegetables, two to three servings of low-fat dairy per day, and <25 percent fat (see table below).  A typical American diet is used as a “less healthy” diet for comparison.

Components of DASH in comparison to a typical modern American diet
( Diet is based on 2,100 calories per day;
Each number on columns is # servings for DASH)

How does DASH benefit us?

In the original 1997 study, 459 people with above-optimal blood pressure were fed for 8 weeks the DASH diet.  After 8 weeks, the group eating the DASH diet saw a reduction of blood pressure by 5.5/3 mmHg, a statistically significant decrease compared to the control group who were eating “less healthy” diet. 

More studies in the following years reveals other benefits of DASH diet.  For instance, in 2018 a meta-study, which looked at a combination of many studies on a collectively 548,632 participants, reported that people who follow DASH diet have reduced their risk for stroke by 12% 3.  In a more recent article the researcher looked at data from 17 previous studies and showed that people who adhere to DASH diet have reduced risk to develop cancers4.

Low sodium provides additional benefits

In 200l, a study combined low sodium intake with DASH diet and tested its effect on blood pressure in 412 participants5. The researchers showed low sodium diet provided additional benefit in reducing blood pressure in people who were already eating the DASH diet.  An average decrease of 8.9/4.5mmHg in blood pressure was seen between DASH diet with low-sodium (1.2g/day) DASH diet and a “less healthy” diet with high-sodium (3.5g/day).

How to start DASH eating?

The National Institutes of Health provided a practical guide to DASH eating plan, including detailed DASH menu for a week.  It is worth noting that DASH diet is not the only diet that has well-recognized health benefits.  For instance, DASH has great overlap with Mediterranean diet, while DASH might suit better the tastes and lifestyle of modern Americans.  It is important to remember that multiple factors contribute to high blood pressure and combination approaches to improve lifestyle in general would be the key to better living.

References

1.         Muntner P, Carey RM, Gidding S, et al. Potential US Population Impact of the 2017 ACC/AHA High Blood Pressure Guideline. Circulation 2018;137(2):109–18.

2.         Appel LJ, Moore TJ, Obarzanek E, et al. A clinical trial of the effects of dietary patterns on blood pressure. DASH Collaborative Research Group. N Engl J Med 1997;336(16):1117–24.

3.         Feng Q, Fan S, Wu Y, et al. Adherence to the dietary approaches to stop hypertension diet and risk of stroke: A meta-analysis of prospective studies. Medicine (Baltimore) 2018;97(38):e12450.

4.         Ali Mohsenpour M, Fallah-Moshkani R, Ghiasvand R, et al. Adherence to Dietary Approaches to Stop Hypertension (DASH)-Style Diet and the Risk of Cancer: A Systematic Review and Meta-Analysis of Cohort Studies. J Am Coll Nutr 2019;38(6):513–25.

5.         Sacks FM, Svetkey LP, Vollmer WM, et al. Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) diet. DASH-Sodium Collaborative Research Group. N Engl J Med 2001;344(1):3–10.

About the Author Isabel Wang, MD/PhD

I received my MD from PUMC in Beijing China and my Ph.D. in Biochemistry from Stony Brook University on Long Island. Over the years, I have worked in the fields of genetic research and clinical medicine in different parts of the US, including PA, MO, CT, FL, NY and MI. My research has been published in multiple scientific journals. Currently I live in Ann Arbor, MI with my husband and our children and Mango the orange tabby. I love hiking, running, baking, cooking and biking.

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