A steady diet of red meat makes the body more susceptible to a virulent form of intestinal bug that can cause bloody diarrhoea and
even death, according to a study.
Researchers in the United States and Australia said persistently
eating red meat appears to prime the body for exposure to this potent
form of Escherichia coli (E. coli). The meat naturally contains sugar molecules called Neu5Gc that accumulate in cells lining the intestines and blood vessels.
These molecules also act as a sort of magnet for the toxins exuded
by the E. coli strain, thus making it easier for the poisons to enter
the blood stream, they said. "Prior meat eating would set one up for the toxin to bind when it shows up," explained Ajit Varki, a researcher at the University of
California at San Diego, one of the study's co-authors.
The Neu5Gc molecule is virtually absent in other foods such as
fish, poultry and vegetables and fruits, Varki said. The investigation, published in the London-based journal Nature, is led by Travis Beddoe of Monash University in Melbourne.
How the study was done
In experiments, the team first tested the affinity of the E. coli bacteria for Neu5Gc using cultured human cells in a lab dish. "The human samples showed the presence of the Neu5Gc toxin binding sites in the gut and the kidney, the two target organs for the
disease," said Varki.
The researchers then confirmed the positive results using
genetically modified mice in which the gene which naturally produced
Neu5Gc was suppressed.
E. coli is found in the lower intestine of animals and humans. Many
of its strains are harmless, but others can cause serious, sometimes
fatal health problems. There are about 75 000 cases of E. coli-related to food poisoning
every year in the United States, including an average of 60 fatalities, according to the Centres for Disease Control and Prevention (CDC) in Atlanta, Georgia.
Most outbreaks have been traced to undercooked ground beef tainted
with faecal matter post-slaughter. E. coli can also be transmitted through unwashed vegetables grown in farmland irrigated by sewage-contaminated water. – (Sapa, October 2008)
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