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n apple a day keeps the doctor away. We've all heard this old
adage, but new research is beginning to shed a scientific understanding
on or grandparents and great grandparents foresite.
Cornell
food scientists have discovered the properities of the apple
that imparts its healthful effects. A combination of plant chemicals,
such as flavanoids and polyphenols - collectively known as phytochemicals
-- found both within the flesh of apple and particularly in
the skin - provide the fruit's anti-oxidant and anti-cancer
benefits.
Although
it has long been known that apples provide anti-oxidant and
health benefits, "this concept is different," says Rui Hai Liu,
Cornell assistant professor of food science and lead author
on the Nature article, "Anti-oxidant activity of fresh apples."
Says Liu:
"Scientists are interested in isolating single compounds --
such as vitamin C, vitamin E and beta carotene -- to see if
they exhibit anti-oxidant or anti-cancer benefits. It turns
out that none of those works alone to reduce cancer. It's the
combination of flavonoids and polyphenols doing the work."
An anti-oxidant
is one of many chemicals that reduce or prevent oxidation, thus
preventing cell and tissue damage from free radicals in the
body.
The researchers
found that vitamin C in apples appears only to be responsible
for a small portion of the anti-oxidant activity. Instead, almost
all of this activity in apples is from phytochemicals. Indeed,
previous studies have shown that a 500 milligram vitamin C pill
might act as a pro-oxidant. The Cornell researchers found that
eating 100 grams of fresh apple with skins provided the total
anti-oxidant activity equal to 1,500 milligrams of vitamin C.
The researchers
used red delicious apples grown in New York state to provide
the extracts to study the effects of phytochemicals. They compared
the anti-cancer and anti-oxidant activity in the apple flesh,
and they also studied the fruit's skin.
Using colon
cancer cells treated with apple extract, the scientists found
that cell proliferation was inhibited. Colon cancer cells treated
with 50 milligrams of apple extract (from the skins) were inhibited
by 43 percent. The apple flesh extract inhibited the colon cancer
cells by 29 percent.
The researchers
also tested the apple extract against human liver cancer cells.
At 50 milligrams, the extract derived from the apple with the
skin on inhibited those cancer cells by 57 percent, and the
apple extract derived from the fruit's fleshy part inhibited
cancer cells by 40 percent.
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