New DASH Diet Improves Heart Health
Federal
health experts kick off the new year with
words of wisdom about healthy diet and
reduction of long-term cardiovascular
health risk.
Findings for the use of the
Dietary Approaches to Stop Hypertension
(DASH) diet were reported at a meeting
of the American Heart Association and
in the Journal of the American Medical
Association (JAMA) .
Two carbohydrate-reduced versions of the
government's DASH diet have a beneficial
effect on blood pressure, cholesterol
levels, and long-term cardiovascular risk,
researchers report.
The
new diet shifts about 10 percent of calories
from carbohydrates to either protein-rich
foods or to monounsaturated fats such
as olive or canola oil.
"This
diet should be a frontrunner," says Dr.
Frank Sacks, one of the authors of the
study and a professor of medicine and
nutrition at Brigham and Women's Hospital
and Harvard in Boston.
"It
improved the whole cardiovascular risk
spectrum," notes Dr. Sacks. "A lot of
patients are tough to control with the
medications we have. Patients might not
even need drugs if they go on the diet."
"This
is a modified version of the old diet,"
Dr. Sacks explains. "The DASH diet was
a real breakthrough for lowering blood
pressure and we changed it. We reduced
the carbohydrate content and replaced
it with unsaturated fat or protein, and
it lowered blood pressure more and improved
lipids, and overall cardiovascular risk
goes down."
He
calls the new regimens "an improvement
over something that's already good."
Another expert agreed that the two new
versions of the DASH diet, as well as
the original DASH , which was developed
by the National Heart, Lung, and Blood
Institute (NHLBI) , should work.
"These
are just alternative versions," says Dr.
Jay Skyler, a professor of medicine and
associate director of the diabetes research
institute at the University of Miami School
of Medicine.
"To
me, whether you get a little bit more
lowering with one or another diet than
the other matters less than the fact that
you ought to stick to any one of these
three," he comments. "They're all better
than the conventional diet that these
people were on."
The DASH diet has been considered the
gold standard of heart-healthy nutrition
since it was pioneered in the mid-1990s.
The
original diet was carbohydrate-rich, emphasizing
fruits, vegetables, and low-fat dairy
products.
Unfortunately,
in addition to lowering "bad" or low-density
lipoprotein (LDL) cholesterol, the regimen
also reduced "good" or high-density lipoprotein
(HDL) cholesterol, and had no effect on
blood fats called triglycerides.
To
help make the regimen even healthier,
the same researchers updated the diet
and compared the two new versions with
the old one.
For this study, 164 adults aged 30 and
older with elevated blood pressure were
assigned to one of three diets: one in
which carbohydrates represented 55 percent
of calories (close to the original DASH
diet); one that shifted 10 percent of
carbohydrate calories to protein (about
two-thirds from plant sources and the
rest from chicken and egg whites); and
one that shifted 10 percent of calories
to unsaturated fat, mostly olive or canola
oils.
About
half of the participants were African
American, a group at especially high risk
of developing hypertension.
All
of the diets lowered participants' blood
pressure, LDL cholesterol, and estimated
coronary heart disease risk, the researchers
report, and the protein and unsaturated
fat diets showed even better improvements.
Compared
to the old diet, the enhanced-protein
version decreased blood pressure by an
extra 1.4 millimeters of mercury (mm Hg)
overall and by an extra 3.5 mm Hg among
those with hypertension; it decreased
LDL cholesterol by an additional 3.3 milligrams
per deciliter (mg/dL) and triglycerides
by 15.7 mg/dL.
Compared to the original DASH diet, the
unsaturated fat-rich version decreased
systolic blood pressure by an additional
1.3 mm Hg overall and by 2.9 mm Hg among
those with hypertension; it increased
HDL cholesterol by an extra 1.1 mg/dL
and lowered triglycerides by 9.6 mg/dL.
Both the protein and unsaturated fat diets
reduced heart disease risk more than the
DASH diet.
Breakfast
was similar in all three diets and included
fresh fruit, fruit juice, whole grain
cereal, and skim milk. Lunches and dinners
were varied. A typical protein-diet dinner
might include one ounce of raisins and
cherries, where the carbohydrate dinner
included a peppermint patty.
How
practical are the improvements? All the
study participants were given their meals.
In the real world, people will have to
prepare these meals themselves.
"Would
people be able to stick to any of these
as effectively when they're doing it at
home? That's the unknown thing here,"
Dr. Skyler says. "I think whatever people
will stick to and are happy with will
work. I would be happy with the results
of any of these three."
Dr.
Sacks says his team was working on making
the diet easy to use.
"Our
next project is to work on foods and menus
and things that people can use, to give
people more specific guidance," he remarks.
"Hopefully that'll be out in a couple
or three months. We feel a sense of urgency
to get some real practical stuff out like
we did with the DASH diet."
An
accompanying editorial also emphasizes
the need for lifestyle changes such as
more exercise, in addition to diet, to
keep blood pressure low.
Always
consult your physician for more information. |
Difficulty breathing, called dyspnea,
is considered a risk factor that could
signal heart trouble, according to a study
reported in the New England Journal of
Medicine .
A
study of nearly 18,000 people who had
standard stress tests found that those
with dyspnea but no other signs of heart
problems were at more than twice the risk
of death from cardiac causes (or any other
reason) than those with angina, the chest
pain that is typically regarded by physicians
as a significant sign of risk.
The
lesson for people when they visit a physician
is to be sure to mention any shortness
of breath, says senior researcher Dr.
Daniel S. Berman, director of cardiac
imaging at Cedars-Sinai Medical Center
in Los Angeles.
"The
patient often doesn't think of it as a
symptom," notes Dr. Berman. But when signs
of a heart problem are discovered, "and
we ask whether there is shortness of breath,
they say 'yes.'"
Dyspnea
has many causes, and physicians routinely
ask people if they have trouble breathing,
says Dr. Alan Rozanski, director of nuclear
cardiology at St. Luke's-Roosevelt Hospital
in New York City, and another member of
the research team.
He
says trouble breathing is often a tip-off
to the physician that a patient may have
some underlying lung disease, maybe even
heart failure.
But
until now, only a few studies, most with
a limited number of participants, have
looked at whether dyspnea is a predictor
of cardiac events, Dr. Rozanski says.
The
New York team divided their 17,991 patients
into five groups based on the number and
type of symptoms: no symptoms, two different
forms of angina, chest pain not caused
by angina, and dyspnea alone.
After
an average follow-up of nearly three years,
the death rate among patients with dyspnea
was significantly higher than for those
with any other symptom or no symptoms
- even in patients with no known history
of coronary artery disease.
The
risk of sudden death was also four times
higher for patients with dyspnea and coronary
artery disease than for people with no
symptoms, the researchers note.
The
bottom line: "People who have developed
shortness of breath without any obvious
lung problem should consider whether it
is of cardiac origin," says Dr. Berman.
"For
years, cardiologists have focused on chest
pain as the primary symptom," he says.
"They consider a variety of other factors
as well, including depression, lack of
sleep, and fatigue. This study increases
interest in looking at other factors."
"We
should think of shortness of breath not
only in terms of lung disease," Dr. Rozanski
adds. "We might need to screen a little
more deeply for coronary artery disease.
Someone with dyspnea might have a heightened
need to undergo stress testing or other
screening."
Dr.
Rozanski says the study is already affecting
decisions on stress testing in his practice.
Now, when evaluating the need for an individual
to have the test, he includes such factors
as age, chest pain, and gender (men are
more likely to be referred for the test).
But
Dr. Rozanski adds there is "one important
caveat."
"This
study was done in a population of middle-
to upper-class white individuals," he
says. "We know that cardiac risk can vary
by gender, ethnicity and other factors.
To see whether dyspnea is as predictive
in African-Americans or Hispanics, another
population study has to be done."
Always
consult your physician for a diagnosis.
(Our
Organization is not responsible for the
content of Internet sites.)
American
College of Cardiology
American
Heart Association
Centers
for Disease Control and Prevention (CDC)
Go
Red for Women Campaign, AHA
Journal
of the American Medical Association
National
Heart, Lung, and Blood Institute (NHLBI)
National
Institutes of Health (NIH)
National
Library of Medicine
National
Women's Health Information Center
New
England Journal of Medicine
NHLBI
DASH Eating Plan
US
Health and Human Services
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