York, November 19, 2004 (ENS): A group of chemicals
in apples could protect the brain from the type of damage
that triggers such diseases as Alzheimer's and Parkinsonism,
according to two new studies from Cornell University
"The studies show that additional apple consumption
not only may help reduce the risk of cancer, as previous
studies have shown, but also that an apple a day may
supply major bioactive compounds, which may play an
important role in reducing the risk of neurodegenerative
disorders," says Chang "Cy" Lee, Cornell
professor of food science at the university's New York
State Agricultural Experiment Station in Geneva, New
The two studies show that the chemical quercetin, a
phytonutrient, appears to protect rat brain cells assaulted
by oxidative stress in laboratory tests.
Phytonutrients, such as phenolic acids and flavonoids,
protect the apple against bacteria, viruses and fungi
and provide the fruit's anti-oxidant and anti-cancer
Quercetin is a major flavonoid in apples. Antioxidants
help prevent cancer by mopping up cell-damaging free
radicals and inhibiting the production of reactive substances
that could damage normal cells.
In a study that recently appeared online and is to
be published in the November/December 2004 issue of
the Journal of Food Science (69(9): S357-60), Lee and
his co-authors compared how two groups of rat neuronal
cells fared against hydrogen peroxide, a common oxidative
Only one of the two groups was pretreated with different
concentrations of apple phenolic extracts. The researchers
found that the higher the concentration of apple phenolic
extract, the greater the protection was for the nerve
cells against oxidative stress.
"What we found was that the apple phenolics, which
are naturally occurring antioxidants found in fresh
apples, can protect nerve cells from neurotoxicity induced
by oxidative stress," Lee said.
When Lee and co-author Ho Jin Heo, a visiting fellow
at Cornell, looked at quercetin they found that quercetin
works even better in protecting nerve cells against
hydrogen peroxide than vitamin C, a naturally occurring
antioxidant known to help prevent cell and tissue damage
from oxidation. Quercetin is primarily found in apples,
berries and onions.
This study will be published in the December issue
of the "Journal of Agricultural and Food Chemistry."
The study on apple phenolics, which was co-authored
by Heo and D.O. Kim, a postdoctoral researcher at Cornell,
as well as S.J. Choi and D.H. Shin at Korea University,
was supported in part by Heo's postdoctoral fellowship
through the Korea Science and Engineering Foundation
(KSEF) and the U.S. Department of Agriculture. The study
on quercetin, authored by Lee and Heo, also was supported,
in part, by the KSEF fellowship program and U.S. Apple
The two studies build on Lee's 2002 findings that quercetin
has stronger anti-cancer activity than vitamin C, and
his 2000 findings that phytochemicals in apples have
stronger anti-oxidant protective effects than vitamin
C against colon and liver cancer cells.
Other studies have found that phytochemicals are associated
with a reduced risk of cancer, heart disease and diabetes,
and that they fight not only cancer but also bacterial
and viral infections. In addition, they are anti-allergenic
Although Lee stresses that his studies were conducted
in the laboratory, not in clinical trials with humans,
he has no hesitation in recommending more apples in
the diet as well as other fresh fruits and vegetables.
"Indeed, I have a reason to say an apple a day
keeps the doctor away."