Harmful proteins fragments known as amyloid fibrils associated with damage to brain cells in Alzheimer's disease and to pancreatic cells in Type II diabetes can be present in the meat of poultry and mammals. These amyloids are not destroyed even with high-temperature cooking process.
Greger, who is the Director of Public Health and Animal Agriculture at the Humane Society of the United States is concerned with this discovery and the transmissibility of amyloid fibrils. Researchers have recently demonstrated in the laboratory that these compounds, when ingested, can enter the organs of laboratory rats fed affected meat.
Greger explains that a biochemical mechanism akin to the replication of similar protein fragments in the brain diseases Creutzfeldt-Jakob Disease (CJD), scrapie, and Bovine Spongiform Encephalopathy (BSE), also known as mad cow disease, might occur when amyloid fibrils enter brain tissue or the pancreas. He points out that high levels of these materials can be found in pâté de foie gras, fatty liver pate, produced by force-feeding poultry.
Stressed poultry birds are known to undergo spontaneous amyloidosis due to a chronic inflammatory response that causes amyloid fibrils to form non-functioning deposits of this protein-like material in their organs. In laboratory tests amyloidosis is found to be accelerated by injection of tiny quantities of amyloid fibrils, which induce production of the malformed proteins strands.
Greger points out that pâté de foie gras is the only food stuff currently known to contain high levels of amyloid fibrils and no demonstration of it affecting people has been seen. However, the suggestion from laboratory research is that amyloid fibrils may be transmitted in a similar way to prion diseases like BSE/CJD is cause for concern.
Mice fed amyloid-affected beef, for instance, succumb to amyloidosis within weeks. Given that amyloidosis can occur in a wide variety of wild as well as domesticated animals, including chickens, cattle, dogs, goats, horses, sheep and, rarely, cats and pigs, Greger suggests that urgent research is now needed to ensure we are not eating food that might one day lead to amyloidosis in people.
"Amyloid fibrils: potential food safety implications" by Michael Greger in the International Journal of Food Safety, Nutrition and Public Health