Recipe For Cancer Protection?
Food compounds may help ward off tumors
Honey, rosemary, curry, and red wine may lower your risk of
cancer if added to your diet. They contain a group of natural
substances that inhibit activation of a gene linked to the development
of pancreatic, breast, colorectal, lung, and other cancers. Curiously,
the compound is similar to drugs that combat inflammation, which
is not only associated with heart discase, but may also play
a role in cancer.
The findings are the result of years spent studying compounds
found in fruits and vegetables by Andrew Dannenberg, MD, Director
of The Strang Cancer Prevention Center and Kotha Subbaramaiah,
PhD, an assistant professor of medicine, at the New York Weill
Cornell Medical Center.
How a gene plays a role
The gene in question is called the cyclooxygenase (or COX-2)
gene. It produces an enzyme associated with cancer by promoting
angiogenesis, the formation of new blood vessels that fuel a
tumor's growth. The enzyme associated with the COX-2 gene may
also inhibit apoptosis (the programmed death of cancer cells).
Seeking novel ways to block this enzyme's production, Dr.
Dannenberg's team has investigated nearly 1,000 natural extracts
which they found to have multiple anti-cancer properties. "We
try to learn exactly how they affect the COX-2 gene," says
His team has identified several natural compounds that deactivate
the COX-2 gene. These substances are found naturally in such
foods as red grapes, fish, rosemary and other herbs, and the
seasoning curcumin, commonly known as turmeric.
The COX-2 deactivator in a supplement called propolis, harvested
from beehives, is CAPE (caffeic acid phenetbyl ester). Propolis
comes in capsules, and is used in salves, ointments, soaps, and
other health care products. Honey itself--a natural source of
energy--contains a wide array of vitamins, minerals, amino acids,
Curious COX compounds
There are actually two types of COX enzymes: COX-1, which
helps to maintain normal body functions, and COX-2 which is released
with inflammation, explains Raymond Sinatra, MD, PhD, professor
of anesthesiology at the Yale University School of Medicine.
Conventional nonsteroidal anti-inflammatory drugs (NSAIDs) such
as aspirin block both COX-1 and COX-2. "COX-2 inhibitors
act by selectively turning off the COX enzymes responsible for
the production of prostaglandins--substances that cause pain
by irritating surrounding nerves," Dr. Sinatra adds.
Several drugs, including celecaxib (Celebrex) and rofecoxib
(Vioxx), are designed to relieve arthritis pain and inflammation
by inhibiting the COX-2 protein. These "selective"
COX-2 inhibitors cause fewer side effects than NSAIDs (although
one recent study raised concern about possibly increased heart
attack risk with Vioxx, because it doesn't have the anti-clotting
properties of aspirin). A study in the September 2001 Lancet
Oncology by Dr. Dannenberg found these drugs may also help prevent
colon cancer (by reducing colon polyps). They are also being
studied for preventing skin, bladder, esophagus, and oral cancers.
Natural COX-2 Inhibitors
Natural COX-2 inhibitors differ from those prescription drugs
in several ways. "The agents we study prevent the protein
from even forming. It's the same molecule, but at an earlier
point," explains Dr. Dannenberg.
It has not yet been proven that natural COX-2 inhibitors will
definitely lower cancer risk in humans, but evidence is growing.
Resveratrol in red grapes, for example, slowed the growth of
human breast cancer cells in the lab. In animal studies at the
National Cancer Institute (NCI), curcumin prevented cancers of
the skin, tongue, stomach, colon, and breast. Curcumin, as turmeric,
is used in India and Southeast Asia to treat tumors, but no controlled
clinical trials have been done. The University of Michigan Medical
School has just begun an NCI-approved clinical trial to study
how curcumin acts in humans.
Drs. Dannenberg and Subbaramaiah look forward to extending
their findings to specific dietary recommendations, and expect
further research to determine how much natural COX-2 inhibitors
people will need to consume to reap the cancer-fighting benefits.
Their work is spearheading a new field of nutrigenomics (the
effect of dietary elements on genes). So far, their research
has been done only on animal models and cultured human cells.
When it comes to lowering cancer risk, "Our data point to
a sound, fundamental understanding of some of the benefits of
fruit and vegetable consumption. The development of nutrigenomics
as a field is likely to lead to dietary recommendations that
may eventually be tailored to a particular individual, based
on her genetic profile," Dr. Dannenberg predicts.
In the meantime, it couldn't hurt to put some of these foods
on your table. They may one day prove to be real lifesavers.
WHAT YOU CAN EAT
The natural COX-2 inhibitors include:
- Curcumin, from turmeric root, used in curries and mustards
for color and flavor.
- Resveratrol, found in red wine and the skin of red grapes.
- Omega-3 fatty acids found in fish like salmon, and fish oils.
- Retinolic acids, in vitamin A, and green or yellow fruits
- Carnosol, found in rosemary.
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