In adults with pre-hypertension to established hypertension, Dietary Approach to Stop Hypertension (DASH) may be the most effective non-drug strategy for reducing blood pressure

Fu J, Liu Y, Zhang L, et al. Nonpharmacologic interventions for reducing blood pressure in adults with prehypertension to established hypertension J Am Heart Assoc. 2020; 9:e016804.

Review question

What is the effect of different non-drug strategies on blood pressure in adults with pre-hypertension to established hypertension compared to usual care? How do these strategies compare to one another? What is the most effective strategy?

Background

Hypertension, also known as high blood pressure, is one of the main risk factors for developing heart disease. By 2025, around 1.5 billion people will be living with hypertension due to factors such as age and unhealthy lifestyles. Medications, which lower blood pressure, are effective primary treatment options, but they are associated with side effects and a risk of treatment resistance, as well as barriers such as cost. Non-drug options for preventing and managing hypertension have been studied in the past, and are recommended in various hypertension guidelines. However, more comprehensive research that better compares different non-drug strategies and provides concrete evidence to support their use is needed.      

How the review was done

This is a network meta-analysis of 126 randomized controlled trials. The studies were published between 1973 and 2016, and included a total of 14, 923 participants. Key features of the studies:

• Participants were adults (average age of 51. 2 years) with pre-hypertension (i.e., risk of developing hypertension) or established hypertension. 
• Participants engaged in one of seven strategies that consisted of a total of 22 non-drug interventions. These included: dietary approaches (i.e., Dietary Approach to Stop Hypertension [DASH], low-sodium and high potassium, or salt restriction); physical exercise (i.e., aerobic, isometric, resistance, tai chi,  or qigong); stress reducing interventions (i.e., breathing control, meditation, mindfulness-based stress reduction, progressive muscle relaxation, or yoga); weight loss interventions (i.e., low-calorie diet, exercise, or both); alcohol restriction; combined interventions (i.e., aerobic exercise plus DASH, aerobic exercise and resistance training, salt restriction plus DASH, salt restriction plus low calories diet plus exercise); or comprehensive lifestyle modification.   
• Researchers measured changes in systolic and diastolic blood pressure.  
• Results were compared to people in control groups engaging in usual care—keeping their regular lifestyle without making changes—or other non-drug interventions.
• Studies lasted between 4 – 144 weeks.

What the researchers found

In people with pre-hypertension to established hypertension, low to high quality evidence shows that DASH, low-sodium and high-potassium salt, salt restriction, low-calorie diet, low-calorie diet plus exercise, breathing control, aerobic exercise, isometric training, yoga, and comprehensive lifestyle modification can reduce both systolic and diastolic blood pressure, compared to usual care. In particular, high quality evidence shows that DASH may be the most effective approach relative to the other tested non-drug strategies. While a number of non-drug strategies may reduce blood pressure, their effects can vary for different populations and outcomes (i.e., systolic or diastolic) of focus. This means certain strategies may be effective for people with pre-hypertension and not those with established hypertension and vice versa, which is important to note when deciding on a treatment plan.   

Conclusion

Various non-drug strategies which fall under the categories of dietary approach, physical exercise, salt restriction, weight loss intervention, stress reduction intervention, and comprehensive life-style intervention can be beneficial for lowering blood pressure in people at risk of hypertension or already living with hypertension. DASH seems to be especially effective in people with pre-hypertension to established hypertension.