Primary prevention of CVD: modification of diet in people with hypertension.

INTRODUCTION: Hypertension (persistent diastolic blood pressure of 90 mmHg or greater or systolic blood pressure 140 mmHg or greater) affects 20% to 35% of the world's adult population and increases the risk of cardiovascular disease, end-stage renal disease, and mortality.

METHODS AND OUTCOMES: We conducted a systematic overview, aiming to answer the following clinical question: What are the effects of selected dietary modification for people with hypertension? We searched: Medline, Embase, The Cochrane Library, and other important databases up to October 2013 (Clinical Evidence overviews are updated periodically; please check our website for the most up-to-date version of this overview).

RESULTS: At this update, searching of electronic databases retrieved 669 studies. After deduplication and removal of conference abstracts, 464 records were screened for inclusion in this overview. Appraisal of titles and abstracts led to the exclusion of 376 studies and the further review of 88 full publications. Of the 88 full articles evaluated, three systematic reviews and three RCTs were added. We performed a GRADE evaluation for eight PICO combinations.

CONCLUSIONS: In this systematic overview, we categorised the efficacy for five interventions based on information about the effectiveness and safety of calcium supplements, a low-salt diet (including the DASH diet), magnesium supplements, a Mediterranean diet, and potassium supplements.