Cancer-causing viruses in poultry may explain increased risks of death from liver and pancreatic cancers.
Thousands of Americans continue to die from asbestos exposure decades after many uses were banned, because the cancers can take years to show up. We are now in the so-called “third wave” of asbestos-related disease. The first wave was in the asbestos miners, which started in the 1920s; the second phase was in the workers—the ship-builders and construction workers that used the stuff in the 30s, 40s, and 50s. Now, as "buildings constructed with asbestos over the past six decades begin to age and deteriorate, not only are workers at risk, but "Potential also exists for serious environmental exposure to asbestos among residents, tenants and users of these buildings, such as school children, office workers, maintenance workers, and the general public.” "The Centers for Disease Control, the American Academy of Pediatrics, and the U.S. Environmental Protection Agency have projected that over the next 30 years approximately 1,000 cases of mesothelioma and lung cancer will occur among persons in the United States exposed to asbestos in school buildings as school children." But it all started with the workers. As one internal industry memo callously put it, "if you've enjoyed a good life while working with asbestos products why not die from it."
To see if something is carcinogenic, you study those who have the most exposure. That's how we learned about the potential cancer-causing dangers of asbestos, and that's how we're learning about the potential cancer-causing dangers of poultry viruses. For years I've talked about the excess mortality in poultry workers associated with these wart-causing chicken cancer viruses that may be transmitted to those in the general population handling fresh or frozen chicken. Last year I talked about the largest study at the time “confirming the findings of three other studies to date that workers in poultry slaughtering and processing plants have increased risk of dying from certain cancers,” and adding penis cancer to the risks linked to poultry exposure. That was looking at 20,000 poultry workers. Well, we have yet another study now looking at 30,000.
The purpose of the study was to "test the hypothesis that exposure to poultry cancer-causing viruses that widely occurs occupationally in poultry workers—not to mention the general population--may be associated with increased risks of deaths from liver and pancreatic cancers." They found that those who slaughter chickens have about 9 times the odds of both pancreatic cancer and liver cancer.
Just to put this in context, the most carefully studied risk factor for pancreatic cancer, one of our deadliest cancers, is cigarette smoking. Even if you smoke for more than 50 years, though, you ‘only’ about double your odds of pancreatic cancer. Those that slaughter poultry appear to have nearly 9 times the odds.
For liver cancer the most well-known and studied cause is alcohol. Those that consume more than a four drinks a day have triple odds of liver cancer. As with pancreatic cancer, poultry slaughtering appears to increase one's odds of getting liver cancer 9-fold.
There are diseases unique to the meat industry, like the newly described "salami brusher's disease" that affects those whose job it is to wire brush off the white mold that naturally grows on salami for 8 hours a day, but most diseases suffered by meat workers are more universal. The reason the connection between asbestos and cancer was so easy to nail down is that asbestos caused a particularly unusual cancer, which was virtually unknown until there was widespread asbestos mining and industrial use. But the pancreatic cancer one might get from eating chicken, is the same pancreatic cancer one might get smoking cigarettes, so it's more difficult to tease out a cause-and-effect-relationship Bottom line: despite the extremely high risks of deadly cancers, don't expect an asbestos-type ban on Kentucky Fried Chicken anytime soon.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Ariel Levitsky.
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I've addressed this topic before. See:
Although workers with the most poultry exposure appear to suffer the greatest excess mortality, increased deaths from cancer are also found in other slaughterhouse workers. More on that in the next video Eating Outside Our Kingdom.
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erratum: at 3:16 I say "lung" cancer. As shown on the slide and in the transcript, I meant to say "liver" cancer--sorry about that! I'll add this to the list of videos to be rerecorded to correct it.