since August 14, 1998
08/13/98 Food, not salt, key to blood pressure, expert says
By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - Food and not salt is the key to
controlling high blood pressure, an expert said Thursday.
David McCarron of the Oregon Health Sciences University in
Portland, Oregon, has been arguing since 1984 that cutting salt
is a waste of time for most people with high blood pressure. But
he says recent studies support his contentions.
``Adequate intake of minerals, rather than restriction of
sodium, should be the focus of dietary recommendations for the
general population,'' McCarron wrote in a commentary in the
journal Science.
One in four American adults has high blood pressure, which
can lead to strokes, heart attacks, and kidney failure.
``I think it's clearly dietary patterns,'' McCarron said in
a telephone interview. He says that as Americans have added junk
food to their diets, blood pressure has gone up.
``When I was a youngster, Coke for me was a treat that I got
on Saturday. What was in the refrigerator was milk, maybe some
reconstituted orange juice, and water. Today you go into a store
and just think about what that beverage shelf contains.''
McCarron's arguments have always been controversial. But as
his main weapon, he cites a study published last year, known as
the Dietary Approaches to Stop Hypertension (DASH) trial.
It showed that people who ate a diet extra rich in fruits
and vegetables, and with a little low-fat dairy replacing much
of the meat and fat, had lower blood pressure than people who
ate ``normal'' American diets or a normal diet with some extra
fruit and vegetables added.
All the diets in the DASH study contained a near normal
level of salt.
The diet that lowered blood pressure the most consisted of
nine daily servings of fruits and vegetables, two servings of
low-fat dairy products, less than one snack or sweet and two to
three servings of fats, oils and salad dressing.
There was one serving of beef, pork or ham every other day,
plus fish or chicken every other day.
Such a diet has many more servings of fruits and vegetables
than most Americans eat -- the average is about two a day -- and
much less meat and fat than average.
A second diet was similar, except it had fewer fruit and
vegetables, no low-fat dairy products, the occasional full-fat
dairy product, two servings of red meat daily and twice as many
fats, snacks and sweets as the first diet.
A third group eating the regular American diet got just over
two daily servings of fruits and vegetables each. They got
plenty of fat and four snacks or sweets a day.
McCarron says it is the minerals in the fruits, vegetables
and dairy products that made the difference. ``Compared to the
effect of the DASH diet, sodium restriction has between
one-tenth and one-20th of the effect,'' he said.
``This is an issue of food and not single nutrients. We need
to stop talking about 'calcium does this' or 'vitamin E does
this.' What is it that we should tell people to eat? We have got
to tell them foods.''
Fruits and vegetables are rich in potassium, magnesium and
sometimes calcium, all of which seem to have a role in blood
pressure. Milk is a major source of calcium for Americans, but
green vegetables, tofu and almonds are also good sources.
The American Heart Association (AHA) says both eating less
salt and eating more minerals and fiber are important for
controlling high blood pressure. The government recommends at
least five servings a day to prevent heart disease and cancer.
The Center for Science in the Public Interest, a nonprofit
organization that often criticizes the food industry, says
McCarron has close ties to the Salt Institute, the National
Dairy Council and to snackmaker Frito-Lay.
``The public should know that his work is part of an
orchestrated effort by the food and salt industries to discredit
the evidence linking salt and hypertension,'' Bonnie Lieberman
of the CSPI said in a statement.
``My commentary in Science is based on all federally
supported trials,'' McCarron responded. ``None of them were
supported by the food industry.''
^REUTERS@
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