London, Oct 30 : An international research team has given two reasons why eating red meat could be bad for you: it increases risk of food poisoning in humans and a regular diet of the animal product can make people more susceptible to E. coli.
The study has been published in Nature.
According to University of California, San Diego School of Medicine professor Ajit Varki, M.D., the team has uncovered the first example of a bacterium that causes food poisoning in humans when it targets a non-human molecule absorbed into the body through red meats such as lamb, pork and beef.
In findings, the boffins discovered that a potent bacterial toxin called subtilase cytotoxin specifically targets human cells that have a non-human, cellular molecule on their surface.
The molecule -N-glycolylneuraminic acid (Neu5Gc) - is a type of glycan, or sugar molecule, that humans don't naturally produce.
Subtilase cytotoxin is produced by certain kinds of E. coli bacteria, causing bloody diarrhea and a potentially fatal disease called haemolytic uraemic syndrome (HUS) in humans. Humans usually become infected after eating contaminated red meat, which is why this is also known as "hamburger" disease.
Varki, UC San Diego School of Medicine distinguished professor of medicine and cellular and molecular medicine, and co-director of the UCSD Glycobiology Research and Training Center, previously discovered that humans don't produce Neu5Gc because they lack the gene responsible for its production. Therefore, it was thought that humans should be resistant to the toxin.
"Ironically, humans may set themselves up for an increased risk of illness from this kind of E. coli bacteria present in contaminated red meat or dairy, because these very same products have high-levels of Neu5Gc," Nature quoted Varki, as saying.
"The Neu5Gc molecule is absorbed into the body, making it a target for the toxin produced by E. coli," the expert added.
In the study, the researchers discovered that sites where the Neu5Gc has been incorporated into the human body coincide with toxin binding.
"When the toxin binds to the non-human Neu5Gc receptors, it can result in serious food-poisoning and other symptoms in humans," said Varki.
The research emphasizes the need for people to eat only well-cook meat or pasteurized dairy products, processes that destroy contaminating bacteria.