Boston (03/15/06)- A recent advisory from the American Heart Association
(AHA) said that soy does little to help lower cholesterol levels. But does
this mean the little white bean which showed so much promise in controlling
cholesterol levels isn't worth it, or was the real health message garbled?
The real story is that soy is still a worthy food to include in your diet,
but in order for it to help, people need to make sure their entire diet is
one that is heart-healthy. In other words, while soy all by itself doesn't
have significant anti-cholesterol super-powers, it does work in concert
with other healthy foods.
"Soy protein has been touted for some special property in lowering
cholesterol. That's what we were looking into and we found not much going
on in that department," said Frank Sacks, MD, lead author of the AHA
advisory published in Circulation. He is professor of nutrition at the Harvard
School of Public Health.
The AHA advisory was based on a review of 22 randomized trials of people
consuming either soy or components of soy. Researchers concluded that "many
soy products should be beneficial to cardiovascular and overall health because
of their high content of polyunsaturated fats, fiber, vitamins, and minerals
and low content of saturated fat."
Public interest in soy peaked in 1999 when the Food and Drug Administration
(FDA) approved labeling for foods containing
soy as being protective against heart disease. While labeling foods with
a health claim can encourage people
to eat specific, healthy foods, some people might think that they can get
a health benefit without changing anything else in their diet or lifestyle.
A claim can give the impression that a food acts like a medication..
The AHA advisory points out that good quality evidence for the cholesterol-lowering
power of soy was weak, and confounded in some studies by the fact study subjects
changed entire dietary patterns with soy being only one component. The FDA
decision to allow a health claim for soy was "premature… If they
had waited (a couple more years) they probably wouldn't have allowed the
health claim," he told Access Excellence in an interview.
"Can the soy protein really give something more than a healthy dietary
pattern could do for you? The answer is no. Why give soy protein an advantage
over, say, other beans, nuts, fish, poultry, other sources of protein?" Dr.
Sacks said. Soy, alone, won’t lower cholesterol significantly, especially
if the other foods in your daily diet consist of greasy hamburgers and polyunsaturated
fat soaked fries. But soy helps if it is used as a substitute for unhealthy
foods – replacing a hamburger with a soy burger. Or ordering either
a vegetarian or a lower-fat chicken chili, instead of a fatty hamburger
style chili. If you don’t like soy, then opt for another food that
lacks cholesterol as a substitute.
Part of the trick to cutting cholesterol is eating fewer foods that contain
cholesterol, supporting the adage 'you are what you eat'. For instance, all
meats contain cholesterol, but eggs and organ meats have the most.
But vegetables simply do not have any cholesterol in them. At the very least,
cut-off the cholesterol-rich fat from meat.
A certain amount of cholesterol is needed
in the human body for cell health, but enough is produced by the liver
and other tissues. Dr. Sacks is also known as one of the creators of the Dietary
Approaches to Stop Hypertension (DASH) diet, a diet proven via clinical
trials to lower
high blood pressure and protect against heart disease.
A new study from the American Journal of Clinical Nutrition found
that cholesterol-lowering foods work even better when they are eaten together.
The study showed a diet
consisting of healthy foods such as soy protein, almonds, oats, barley and
plant-sterol enriched margarines, lowered cholesterol in subjects as much
as statins (medications for lowering cholesterol) did. The researchers, from
the University of Toronto (U of T), cautioned that high-risk people who are
already taking statins shouldn't stop the medication, but that a healthy
diet should be part of their treatment.
David Jenkins, MD, professor of nutrition sciences at the U of T agrees
soy is a worthy food to include in a heart-healthy diet. "You take soy
as part of the diet. It's not the only thing, it's just part of the thing." In
the past, when there were claims soy could cut cholesterol by as much as
12%, he quoted much more conservative numbers to his patients. Dr. Jenkins
helped develop the vegetarian Portfolio
Diet which emphasizes use of soy
protein, psyllium,
nuts, foods high in fiber and sterol-enriched margarines.
If you do include soy products, read the label. Some soy products include
ingredients that aren't so heart-healthy which may even counter the effect
of soy—for
example make sure your soy ice-cream doesn't actually include real cream.
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