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| Salt Intake & High Blood Pressure |
Latest research finds a high salt intake does drive up blood pressure,
both in people with and without elevated pressure, according to a
study released recently at the annual meeting of the American Society
of Hypertension.
The $12 million "DASH-Sodium" study suggests that an intake of sodium
below the current recommended daily level of 2,400 milligrams1
could help Americans prevent blood pressure rises that occur especially
with advancing age. Sodium is a main ingredient of table salt, whose chemical
name is sodium chloride.
The study, conducted by the National Heart, Lung, and Blood Institute
(NHLBI), involved 412 subjects aged 22 and older whose diets were
carefully controlled and monitored over 14 weeks. Patients were divided
into two diet regime, a diet of foods usually eaten by Americans and the
"DASH" diet which provided large servings of fruits, vegetables and low-fat
dairy foods and low in saturated fat, total fat and cholesterol.
Food was provided for all participants in the trial and they were given 3 levels
of sodium (1,500 mg, 2,400 mg, and 3,300 mg) over the course of the three-month
study. Forty-one percent of the participants had high blood pressure and all
subjects’ blood pressure were closely monitored.
"Results showed that reducing dietary sodium lowered blood pressure
for both the usual and DASH diets. The lower the sodium intake, the
lower the blood pressure," NHLBI said in their press release.
"The biggest reductions in blood pressure were found among those who
followed the DASH diet at the lower sodium (1,500 mg sodium per day)
intake.
That combination reduced blood pressure amongst all the groups
in the study by more than either the DASH diet or lower sodium alone,"
said the agency, which is a part of the National Institute of Health.
Results were most impressive in patients that have hypertension, where
the combination of the DASH diet and lower sodium cut systolic blood
pressure by an average of 11.5 mm. In those without hypertension, the
combination reduced systolic pressure by 7.1 mm of mercury.
On average, the DASH diet combined with lower sodium intake reduced
systolic blood pressure -- the "top" number in a blood pressure reading
-- by an average of 8.9 millimeters of mercury. And it reduced
the diastolic blood pressure -- the "bottom" number -- by an average of
4.5 mm of mercury. Decrease in blood pressure were noted between the
"intermediate" level of sodium of 2,400 mg per day and the "higher"
sodium intake of 3,300 mg per day.
It is a challenge to cut back on salt intake. 1,500-mg sodium diet takes some
getting used to. It rules out a lot of pre-packaged foods & eating out as
most food outlets use a lot of salt for flavour in their food preparation.
It also means putting away the salt shaker.
"But the diet is possible, and potentially could prevent many heart attacks
and strokes, especially for those with serious hypertension." commented
Dr. Frank Sacks, a Harvard researcher who was in charge of the study.
"At first the food tastes bland, but after a while your taste buds
adjust. They get acclimated," he said.
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