Blueberry compounds linked to colon cancer prevent
3/26/2007
Pterostilbene, a compound found in blueberries, may prevent the
development of tumours in the colon, if results from an animal
study can be translated to humans, researchers have said.
Researchers from Rutgers University told attendees at the 233rd
national meeting of the American Chemical Society that rats supplemented
with pterostilbene had 57 per cent fewer pre-cancerous lesions
in the colon than rats not supplemented with the blueberry compound.
The research could boost further the healthy image of the berry,
already firmly engrained in consumer's minds for its apparent cholesterol
lowering abilities, as well as indications that the fruit could
offer protection from neurodegenerative diseases like Alzheimer's.
Sales of the fruit have been booming, going from £10.3m
(€14.9m) in 2003 to almost £40m (€58m) in 2005,
according to UK supplier BerryWorld, driven by dieticians and scientists
hailing the fruit as one of nature's superfoods.
"To our knowledge, our studies are the first to show
that administration of a blueberry constituent, pterostilbene,
strongly inhibits the development of early pre-neoplastic lesions
in the colon,"
lead researcher Bandaru Reddy told attendees in Chicago.
Reddy and co-workers conducted a small pilot study with 18 rats
given a compound (azoxymethane) to induce colon cancer in a manner
similar to human colon cancer development.
Half of the animals were then placed on a balanced daily diet,
while the other nine were given the same diet supplemented with
pterostilbene (40 parts per million).
At the end of an eight-week study period, Reddy and collaborators
from the USDA's Agricultural Research Service and the University
of Oklahoma, found that the pterostilbene-supplemented rats showed
57 per cent fewer pre-cancerous lesions in their colon in comparison
to the control group.
They also report that the blueberry compound reduced colonic cell
proliferation and inhibited certain genes involved in inflammation,
both of which are considered colon cancer risk factors.
"The results of the study suggest that naturally occurring
components offer an attractive alternative for the prevention
of colon cancer," said Reddy.
"Our results may support dietary prevention of colon
cancer and health benefits of blueberries."
There are 363,000 new cases of colorectal cancer every year in
Europe, the incidence of the cancer is rising, especially in Southern
and Eastern Europe. Eighty per cent of colorectal cancers may be
preventable by dietary changes. It is also one of the most curable
cancers if diagnosis is made early.
The humble blueberry's cholesterol-lowering activity was also
given a boost at the ACS meeting, with Agnes Rimando, co-researcher
on the colon cancer study, reporting that hamsters fed a high-cholesterol
diet containing blueberry skins (7.6 per cent of the diet) had
lower levels of plasma and liver triglycerides (TGs), LDL-cholesterol,
free and total cholesterol of 39, 18, 19, 30 and 37 per cent, respectively,
compared to animals fed the control diet. Source: 233rd national
meeting of the American Chemical Society March 25 2007, Abstract:
AGFC 009
"Novel approaches for colon cancer prevention by types
of dietary fat, pterostilbene and other food components"
Authors: B.S. Reddy, H. Newmark, N. Suh, A.M. Rimando, and C.V.
Rao 233rd national meeting of the American Chemical Society March
26 2007, Abstract: AGFC 038 "Blueberry skins lower plasma
and liver cholesterol and triglycerides in hypercholesterolemic
hamsters" Authors: A.M. Rimando, W.H. Yokoyama, A. Patny,
M.A. Avery, C.S. Mizuno
|
