A low-salt diet combined with the DASH diet (The Dietary Approaches to Stop Hypertension) substantially lowers systolic blood pressure – the top number in a blood pressure test – according to new research published in the Journal of the American College of Cardiology.
The DASH diet is rich in fruits, vegetables and whole grains, along with low-fat or fat-free dairy, fish, poultry, beans, seeds and nuts.
The study was designed to examine the effects of combining the two diets in adults with early or modest forms of high blood pressure – those considered to be at greatest risk of developing more severe forms of hypertension known to increase the likelihood of stroke, kidney disease, heart attacks and heart failure.
During the study, researchers tested and followed 412 adults, including 234 women, between the ages of 23 and 76 years and with a systolic blood pressure of 120-159 mm Hg and a diastolic blood pressure between 80-95 mm Hg (i.e., prehypertension or stage 1 hypertension).
At the start of the study, none of the participants was taking antihypertensive drugs or insulin, none had a prior diagnosis of or current heart disease, renal insufficiency, poorly controlled cholesterol levels or diabetes.
Investigators put all participants on the DASH diet or a control diet for 12 weeks. Participants were also fed 50 (low), 100 (medium) or 150 (high) mmol/day of salt in random order over four-week periods.
After four weeks, the researchers found that the group with 150 or greater baseline systolic blood pressure on just the DASH diet had an average of 11 mm Hg reduction in systolic blood pressure compared to a 4 mm Hg reduction in those solely on the DASH diet, but whose baseline systolic pressures were less than 130.
Stephen Juraschek, the study’s lead author, said: ‘Our results add to the evidence that dietary interventions are as effective as – or more effective than – antihypertensive drugs in those at highest risk for high blood pressure, and should be a routine first-line treatment option for such individuals.’
‘What we’re observing from the combined dietary intervention is a reduction in systolic blood pressure as high as, if not greater than, that achieved with prescription drugs.’