Doctor warns of mad cow disease

Michael Greger, Ph.D., visited Hoyt Auditorium to tell the other side of the story about mad cow disease on Feb. 28. He started his lecture by stating the fact that over 76 million Americans, roughly one in five, contract some form of food poisoning a year. He hinted that some minor forms of illness, such as a 24-hour flu, may be a form of food poisoning. Microbes found in meat, such as E. coli and salmonella, are showing up in increasingly high frequencies and are largely responsible for the incidences of food poisoning. Even more worrying to some are the recent outbreaks of mad cow disease in Europe and North America, with the potential to become a global epidemic.Stanley Pruisner discovered that mad cow disease or Bovine Spongiform Encephalopathy was being caused by prions, winning the Nobel Prize in medicine for his work. Prions are bio-molecules that are “practically invulnerable [to most detoxification methods],” Greger stated in his lecture. “Even incineration does not work.” Creutzfeldt Jakob Disease is the disease found in humans caused by eating meat containing prions. The nerve tissue in people who have CJD would also contain prions.The difficulty of killing prions makes sterilization extremely problematic, according to Greger. It’s possible for meat to become contaminated by coming in contact with a knife that has been used on an infected animal. This means that surgical tools not properly cleaned after coming into contact with tissues containing prions from a person with CJD could potentially infect the next person they are used on. Greger stated during his lecture that American officials have banned all blood from Europe and made it impossible for someone who has spent more than two months in Europe to donate blood. Great Britain has also discarded their entire supply of blood from fears of contamination.In addition, researchers at Yale University have recently found evidence that CJD may in fact be responsible for hundreds of deaths in America. Pruisner believes that most diagnoses of Alzheimer’s disease are given to patients who are actually suffering from a prion-related disease. The fact that CJD can linger in a person, or an animal, for decades without showing symptoms, coupled with the difficulty of obtaining tissues with the highest prion concentration – brain matter – makes it very hard toSee DISEASE, Page 8Continued from Page 5detect cases of it. Scientists at Yale performed autopsies on cadavers whose cause of death was listed as Alzheimer’s. They concluded that between three percent and 13 percent had signs of CJD, with the classic holes in nerve tissues and proliferation of prions throughout. According to Greger this suggests hundreds if not thousands of deaths in America are falsely diagnosed as Alzheimer’s and that people are dying from CJD every year. To ascertain the risk of contracting CJD one must consider the major sources of infection. Since the disease has such a long incubation period, it is almost impossible to tell how and when a person was first exposed to the disease. Greger believes the number of animals who are infected is grossly underestimated. Medical Director of the U.S. Public Health Service, Paul Brown believes that pigs and poultry could be harboring the disease in addition to cattle, and that humans may be contracting it from them.”[Eating beef] is kind of like unsafe sex – you’re not just eating that cow, you’re eating every cow that that cow ate,” Greger said, referring to what he likens to the recycling of livestock. “Farmers can grind up cows and feed them to chickens and then feed the chicken droppings to the cattle.”Since the outbreak of mad cow disease, the World Health Organization has made the recommendation that, in order to keep the food chain as safe as possible, no “part or product” of any mad cow-like disease be fed to any other animal. Greger noted, “In the U.S. it remains legal to feed deer and elk known to be infected with a transmissible spongiform encephalopathy called chronic wasting disease and to feed downer cows untested for mad cow disease to livestock such as pigs and chickens.” Greger also addressed the issue of which parts of the cow can contain the disease. Prions normally dwell within the nerve tissues of an infected animal but can spread to other regions when the animal is killed. The majority of cattle are killed with pneumatic stunning devices that drive bolts into their skulls – the force of the impact can scatter brain fragments throughout their bodies. One study at Texas A&M University found pieces of brain as large as 14 cm in the lungs of a slaughtered bovine. Students who attended the event found it to be very insightful. Junior Megan Ann Walter said “I thought it was very interesting and enlightening. It kind of scared me, I didn’t know how long the incubation period was and that CJD might be more common.” Greger hoped that by sharing his knowledge he will “encourage people to pressure the public officials [to change food safety laws].” He is a general practitioner who owns a private practice in Boston and is a vegan.