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Study under review: Comparative effects of different dietary approaches on blood pressure in hypertensive and pre-hypertensive patients: A systematic review and network metaanalysis
Introduction
Over one billion[1] adults suffer from high blood pressure, or hypertension, worldwide. It affects one in four men and one in five women. Heart disease is the number one[2] cause of death in the world, and hypertension is one of its leading risk factors[3]. The global direct medical costs[4] of hypertension are estimated at $370 billion per year, while savings from effective management of blood pressure are projected at about $100 billion per year.
Current management and treatment for hypertension commonly involves medication, supplements, and/or lifestyle changes. The average reductions in systolic and diastolic blood pressure for antihypertensive drugs, supplements, diets, and exercise have been reported[5] to be 9/5 mmHg, 4/2 mmHg, 6/4 mmHg, and 5/3 mmHg, respectively. While drugs are generally the most effective way to reduce blood pressure, adherence can be surprisingly low, reported at 18.8% of participants in one study[6].
On the other hand, dietary approaches to reduce blood pressure (BP) are effective and have reported adherence levels of up to 95%[7]. But, which dietary approach is best? Unfortunately, guidelines sometimes emphasize different aspects of diet, and are occasionally inconsistent with one another. For instance, the American Heart Association’s guidelines[8] suggest that hypertensive and prehypertensive people should consume less alcohol and sodium and more fruits, vegetables, and low-fat dairy products. The European Society of Hypertension and European Society of Cardiology[9] guidelines, on the other hand, includes extra emphasis on reductions in saturated fat and cholesterol, accompanied by increases in fiber and plant protein.
These inconsistencies become all the more obvious when considering all the different dietary approaches that exist in the context of blood pressure reduction. To list a few, the Dietary Approaches to Stop Hypertension (DASH) diet[10], the Mediterranean diet[11], and a simple low-sodium diet all have evidence suggesting they have some impact on BP. Are all of these equally effective? The study under review sought to answer this question by performing a network meta-analysis of randomized controlled trials (RCTs) comparing anti-hypertensive diets.
The prevalence of hypertension is high and increasing, impacting global mortality and health costs. A variety of diets are recommended for and have demonstrated efficiency at lowering blood pressure. The study under review was designed to compare these diets, so as to establish a clinically meaningful hierarchy of antihypertensive dietary patterns.
Who and what was studied?
What were the findings?
What does the study really tell us?
The big picture
Frequently asked questions
What should I know?
Other Articles in Issue #46 (August 2018)
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NERD Mini: Exercise recommendations for people with different cardiovascular disease risk factors
There’s little question that exercise is generally useful for reducing the risk of CVD. But do different risk factors require different doses and forms of exercise? We summarize some experts’ consensus statements on the matter here.
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NERD Mini: Expert consensus statements on multivitamin and multimineral supplement use
Nutritional experts came to a consensus on nine statements about multivitamin and multimineral supplement use. Take a peek at what they came up with.
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Does overeating on a keto diet help build muscle?
There’s been quite a bit of research on keto dieting’s effect on some disease states, but relatively little on its effect on body composition in strength training, especially when the diet’s hypercaloric. This research aimed to fill the gap.
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Are diet drinks really a sweet deal?
Diet drinks using low-energy sweeteners are supposed to help with weight loss. But some research has suggested that they could actually stimulate appetite and food intake. This study explores the issue.
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Is melatonin useful for more than just sleep?
There are lots of diets out there that can lower blood pressure. This network meta-analysis looked at which ones work best.
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Do saturated fats fatten up your liver?
Overfeeding can contribute to non-alcoholic fatty liver disease, but does the type of macronutrient that's consumed also play a role?
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Got (chocolate) milk?
Chocolate milk has a lot of things going for it that could make it a great exercise recovery beverage. While lots of small studies have examined whether it works, this is the first meta-analysis to attempt to synthesize the evidence.