After just a month, the results for people adopting this strategy were “striking and reinforce the importance of dietary changes” for those with problematic blood pressure. So says a team of researchers led by Dr Stephen Juraschek, of Beth Israel Deaconess Medical Centre in Boston.
Millions of Americans fight a daily battle with high blood pressure, which can greatly increase their odds for stroke and other heart events.
What’s the best dietary strategy to lower those blood pressure numbers?
One key factor that’s long been linked to blood pressure is salt (sodium) intake. In the new study, 412 people with high blood pressure (or in danger of high blood pressure) were assigned to one of three daily salt-intake regimens.
Some took in about half of a teaspoon of salt a day; some had about a teaspoon of salt a day, while others consumed about 1.5 teaspoons of salt a day.
Current recommendations from the US Food and Drug Administration call for a daily limit of about one teaspoon of salt a day.
The study participants, who averaged 48 years of age, were also randomly asked to stay on either a “regular” diet or switch to the healthier Dietary Approaches to Stop Hypertension (Dash) regimen.
This diet is often recommend by doctors and nutritionists and focuses on fruits, vegetables, whole grains, low or fat-free dairy, fish, poultry, beans, seeds and nuts.
The participants’ blood pressure averaged 135/86 mm/Hg at the start of the four-week study.
At the end of that time, results varied greatly depending which regimen the person had followed.
For example, for people who continued taking in higher amounts of salt, switching to the Dash diet brought down systolic blood pressure by anywhere from 4.5 to nearly 11 points, with the benefits higher for people who’d started the trial at the highest blood pressures.
Systolic blood pressure is the top number in a reading.
The effect was even more robust, however, for people who were on the Dash diet and cut their daily salt intake, Juraschek’s team said.
For example, people who started the trial with systolic blood pressure readings at or above 150mm/Hg saw an average decline of almost 21 points if they ate healthier and slashed their salt intake.
Even people with “mid-range” hypertension lost an average of 7 to nearly 10 points in systolic blood pressure if they cut their salt and switched over to Dash, the study found.
Juraschek’s team says further research is needed to determine if the combo diet has the same effect for adults with systolic blood pressure that rises even above 160mmHg.
Two heart specialists were encouraged by the results.
“This study provides compelling evidence that people who adhere to a Dash diet improve at all levels of hypertension risk,” said Dr Benjamin Hirsch.
He directs preventive cardiology at Northwell Health’s Sandra Atlas Bass Heart Hospital in Manhasset, New York.
Antonella Apicella is an outpatient dietitian who helps counsel heart patients at Lenox Hill Hospital in New York City.
She said that “although positive effects on systolic blood pressure were also seen in individuals who followed a low-sodium or Dash diet alone, this study supports the notion that the combination ... is most beneficial for blood pressure control in individuals with pre- or stage 1 hypertension.” - New York Times