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Winter 03-04 index CivAb index previous page BSE Update and Review by Michael Greger, MD Autumn 83--Spring 84 issue of CivAb First, an appeal for a good cause: BUT THAT WAS THEN NOW, DR GREGER IS DIRECTOR OF PUBLIC HEALTH AND ANIMAL AGRICULTURE FOR THE HUMANE SOCIETY OF THE UNITED STATES Some copies of CivAb's autumn issue citing evidence that BSE is present in USA were still in the mail when the first officially recognized "mad cow" turned up in the state of Washington. At the risk of belaboring the issue we are devoting the space to Dr Michael Greger's recap, new information and assessment of BSE in USA because of the Government's reluctance to fully address this situation. We are leaving in reference numbers and apologize for lack of space to print them. They are available at http://www.organicconsumers.org/madcow/GregerCJDkills.cfm In October 2001, 34-year-old Washington State native Peter Putnam started losing his mind. One month he was delivering a keynote business address, the next he couldn't form a complete sentence. Once athletic, soon he couldn't walk. Then he couldn't eat. After a brain biopsy showed it was Creutzfeldt-Jakob disease, his doctor could no longer offer any hope. "Just take him home and love him," the doctor counseled his family.[1,2,3] Peter's tragic death, October 2002, may have been caused by Mad Cow disease. Seven years earlier and 5000 miles away, Stephen Churchill was the first in England to die. His first symptoms of depression and dizziness gave way to a living nightmare of terrifying hallucinations; he was dead in 12 months at age 19.[4] Next was Peter Hall, 20, who showed the first signs of depression around Christmas, 1994. By the next Christmas, he couldn't walk, talk, or do anything for himself.[5] Then it was Anna's turn, then Michelle's. Michelle Bowen, age 29, died in a coma three weeks after giving birth to her son via emergency cesarean section. Then it was Alison's turn. These were the first five named victims of Britain's Mad Cow epidemic. They died from what the British Secretary of Health called the worst form of death imaginable, Creutzfeldt-Jakob disease, a relentlessly progressive and invariably fatal human dementia.[6] The announcement of their deaths, released on March 20, 1996 (ironically, Meatout Day[7]), reversed the British government's decade-old stance that British beef was safe to eat.[8] It is now considered an "incontestable fact" that these human deaths in Britain were caused by Bovine Spongiform Encephalopathy (BSE), or Mad Cow disease.[9] BSE is caused by unconventional pathogens called prions--literally infectious proteins--which, because of their unique structure, are practically invulnerable, surviving even incineration[10] at temperatures hot enough to melt lead.[11] The leading theory as to how cows got Mad Cow disease in the first place is by eating diseased sheep infected with a sheep spongiform encephalopathy called scrapie.[12] In humans, prions can cause Creutzfeldt-Jakob disease (CJD), a human spongiform encephalopathy whose clinical picture can involve weekly deterioration into blindness and epilepsy as one's brain becomes riddled with tiny holes. We've known about Creutzfeldt-Jakob disease for decades, since well before the first mad cow was discovered in 1985. Some cases of CJD seemed to run in families; other cases seemed to just arise spontaneously in about one in a million people every year, and were hence dubbed "sporadic." The new form of CJD caused by eating beef from cows infected with Mad Cow disease, though, seemed to differ from the classic sporadic CJD. The CJD caused by infected meat has tended to strike younger people, has produced more psychotic symptoms, and has often dragged on for a year or more. The most defining characteristic, though, was found when their brains were sampled. The brain pathology was vividly reminiscent of Kuru, a disease once found in a New Guinea tribe of cannibals who ate the brains of their dead.[13] Scientists called this new form of the disease "variant" CJD. Other than Charlene, a 24 year old woman now so tragically dying in Florida, who was probably infected in Britain, there have been no reported cases of variant CJD in the U.S.[14] Hundreds of confirmed cases of the sporadic form of Creutzfeldt-Jakob disease, however, arise in the United States every year,[15] but the beef industry is quick to point out these are cases of sporadic CJD, not the new variant known to be caused by Mad Cow disease.[16] Of course, no one knows what causes sporadic CJD. New research, discussed below, suggests that not hundreds but thousands of Americans die of sporadic CJD every year, and that some of these CJD deaths may be caused by eating infected meat after all. Although the fact that Mad Cow disease causes variant CJD had already been strongly established, researchers at the University College of London nevertheless created transgenic mice complete with "humanized" brains genetically engineered with human genes to try to prove the link once and for all. When the researchers injected one strain of the "humanized" mice with infected cow brains, they came down with the same brain damage seen in human variant CJD, as expected. But when they tried this in a different strain of transgenic "humanized" mice, those mice got sick too, but most got sick from what looked exactly like sporadic CJD! The Mad Cow prions caused a disease that had a molecular signature indistinguishable from sporadic CJD. To the extent that animal experiments can simulate human results, their shocking conclusion was that eating infected meat might be responsible for some cases of sporadic CJD in addition to the expected variant CJD. The researchers concluded that "it is therefore possible that some patients with [what looks like]... sporadic CJD may have a disease arising from BSE exposure."[17] Laura Manuelidis, section chief of surgery in the neuropathology department at Yale University comments, "Now people are beinning to realize that because something looks like sporadic CJD they can't necessarily conclude that it's not linked to [Mad Cow disease]..."[18] This is not the first time meat was linked to sporadic CJD. In 2001, a team of French researchers found, to their complete surprise, a strain of scrapie--"mad sheep" disease--that caused the same brain damage in mice as sporadic CJD.[19] "This means we cannot rule out that at least some sporadic CJD may be caused by some strains of Population studies had failed to show a link between CJD and lamb chops, but this French research provided an explanation why. There seem to be six types of sporadic CJD and there are more than 20 strains of scrapie. If only some sheep strains affect only some people, studies of entire populations may not clearly show the relationship. Monkeys fed infected sheep brains certainly come down with the disease.[21] Hundreds of "mad sheep" were found in the U.S. in 2003.[22] Scrapie remains such a problem in the United States that the USDA has issued a scrapie "declaration of emergency." [23] Maybe some of sporadic CJD in the U.S. is caused by sheep meat as well.[24] Pork is also a potential source of infection. Cattle remains are still boiled down and legally fed to pigs (as well as chickens) in this country. The FDA allows this exemption because no "naturally occurring" porcine (pig) spongiform encephalopathy has ever been found. But American farmers typically kill pigs at just five months of age, long before the disease is expected to show symptoms. And, because pigs are packed so tightly together, it would be difficult to spot neurological conditions like spongiform encephalopathies, whose most obvious symptoms are movement and gait disturbances. We do know, however, that pigs are susceptible to the disease--laboratory experiments show that pigs can indeed be infected by Mad Cow brains[25]--and hundreds of thousands of downer pigs, too sick or crippled by injury to even walk, arrive at U.S. slaughterhouses every year.[26] A number of epidemiological studies have suggested a link between pork consumption and sporadic CJD. Analyzing peoples' diet histories, the development of CJD was associated with eating roast pork, ham, hot dogs, pork chops, smoked pork, and scrapple (a kind of pork pudding made from various hog carcass scraps). The researchers concluded: "The present study indicated that consumption of pork as well as its processed products (e.g., ham, scraple) may be considered as risk factors in the development of Creutzfeldt-Jakob disease." Compared to people that didn't eat ham, for example, those who included ham in their diet seemed ten times more likely to develop CJD.[27] In fact, the USDA may have actually recorded an outbreak of "mad pig" disease in New York 25 years ago, but still refuses to reopen the investigation despite petitions from the Consumer's Union (the publishers of Consumer Reports magazine).[28] Sporadic CJD has also been associated with weekly beef consumption,[29] as well as the consumption of roast lamb,[30] veal, venison, brains in general,[31] and, in North America, seafood.[32,33] The development of CJD has also, surprisingly, been significantly linked to exposure to animal products in fertilizer,[34] sport fishing and deer hunting in the U.S.,[35] and frequent exposure to leather products.[36] We do not know at this time whether chicken meat poses a risk. There was a preliminary report of ostriches allegedly fed risky feed in German zoos who seemed to come down with a spongiform encephalopathy.[37] Even if chickens and turkeys themselves are not susceptible, though, they may become so-called "silent carriers" of Mad Cow prions and pass them on to human consumers.[38] Dateline NBC quoted D. Carleton Gajdusek, the first to be awarded a Nobel Prize in Medicine for his work on prion diseases,[39] as saying, "it's got to be in the pigs as well as the cattle. It's got to be passing through the chickens."[40] Dr. Paul Brown, medical director for the US Public Health Service, believes that pigs and poultry could indeed be harboring Mad Cow disease and passing it on to humans, adding that pigs are especially sensitive to the disease. "It's speculation," he says, "but I am perfectly serious."[41] The recent exclusion of most cow brains, eyes, spinal cords, and intestines from the human food supply may make beef safer, but where are those tissues going? These potentially infectious tissues continue to go into animal feed for chickens, other poultry, pigs, and pets (as well as being rendered into products like tallow for use in cosmetics, the safety of which is currently under review[42]). Until the federal government stops the feeding of slaughterhouse waste, manure, and blood to all farm animals, the safety of meat in America cannot be guaranteed. The hundreds of American families stricken by sporadic CJD every year have been told that it just occurs by random chance. Professor Collinge, the head of the University College of London lab, noted "When you counsel those who have the classical sporadic disease, you tell them that it arises spontaneously out of the blue. I guess we can no longer say that." "We are not saying that all or even most cases of sporadic CJD are as a result of BSE exposure," Professor Collinge continued, "but some more recent cases may be--the incidence of sporadic CJD has shown an upward trend in the UK over the last decade... serious consideration should be given to a proportion of this rise being BSE-re-related. Switzerland, which has had a substantial BSE epidemic, has noted a sharp recent increase in sporadic CJD."[43] In the Nineties, Switzerland had the highest rate of Mad Cow disease in continental Europe, and their rate of sporadic CJD doubled.[44] We don't know exactly what's happening to the rate of CJD in this country, in part because CJD is not an officially notifiable illness.[45] Currently only a few states have such a requirement. Because the Centers for Disease Control (CDC) does not actively monitor the disease on a national level,[46] a rise similar to the one in Europe could be missed.[47] In spite of this, a number of U.S. CJD clusters have already been found. In the largest known REFERENCES: can be checcked at http://www.organicconsumers.org/madcow/GregerCJDkills.cfm |
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The Civil Abolitionist Winter 2003-2004 v.14 no. 3 |