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Despite
all the questions about how much of our diet carbohydrates
should make up, researchers say we may be overlooking a more
important issue: the kinds of carbohydrates we eat. Studies
now demonstrate quite clearly that carbohydrates like white
bread and sweets can’t provide the kind of the health
benefits offered by whole-grain breads, fruit and vegetables.
Forty studies have linked regular consumption of whole grains
with a 10 percent to 60 percent lower risk of certain cancers,
especially cancers of the stomach and colon. Several large
studies have found greater use of whole grains associated
with lower risk of heart disease, too. In the Iowa Women’s
Health Study, those who ate the most whole grains suffered
about 20 percent fewer heart disease deaths and 10 percent
fewer cancer-related deaths than those who ate the least,
even after controlling for the effects of weight, smoking
and other dietary habits.
At first, the health benefits of whole grains were attributed
to dietary fiber. But since the discovery of natural, health-promoting
phytochemicals and the growing recognition of the importance
of antioxidants, scientists now place more emphasis on whole
grains as a package of vital substances. Studies have shown
that some of the phytochemicals in whole grains can block
DNA damage that could lead to cancer. They can even suppress
growth of cancer cells.
The outer layer of whole grains contains lignans, a form of
phytoestrogen that may help protect against hormonally related
cancers. Whole grains also provide a variety of trace minerals
and antioxidant nutrients like vitamin E and selenium but,
when grains are refined, 70 percent to 80 percent of many
of these valuable substances are lost.
HEALTH BENEFITS
Is it possible that the health benefits attributed to eating
whole grains are really due to other habits? It’s true
that several studies noted that those who ate more whole grains
also ate more fruits and vegetables, clearly a major step
in lower heart disease and cancer risk. In fact, the American
Institute for Cancer Research says that 20 percent of cancers
could be prevented by eating the recommended amounts of fruits
and vegetables. Several studies, however, including the Iowa
Study noted above, showed that the benefits of eating more
whole grains remained significant, even after allowing for
other eating habits like eating more fresh vegetables and
fruits, or avoiding excessive amounts of meat.
HOW MUCH?
How much does it take? The group of people in the Iowa Women’s
Health Study who ate the most whole grains actually consumed
just over the minimum recommended, which is three servings
a day. Although that’s significant compared to the group
that ate only one or two servings a week, three a day is not
a difficult target to reach.
At breakfast, choose a whole-grain cereal, toast, or bagel.
Depending on your portion size, that could equal one or two
servings. If you have a sandwich at lunch made with whole-wheat
bread, you’ve already met the goal. For other sources
of whole-grain nutrition, choose brown rice, corn or whole-wheat
tortillas and whole-wheat pasta. If you use mixes to prepare
muffins and quick breads, make them from scratch instead,
substituting whole-wheat flour. That only takes a few extra
minutes but results in lots of extra nutrition.
A diet centered on white bread, fat-free cookies,
pretzels and bagels is not a basis for good health. We need
to focus on a variety of whole grains, vegetables, fruits
and beans for the many different health benefits they bring,
as well as their great taste.
© 2002 Newsweek, Inc., Sept. 23, 2002
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