What was the response to the revelation that as many as 37 percent of breast cancer cases may be attributable to exposure to bovine leukemia virus, a cancer-causing cow virus found in the milk of nearly every dairy herd in the United States?
Industry Response to Bovine Leukemia Virus in Breast Cancer
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
What was the response to the revelation that as many as 37% of breast cancer cases may be attributable to exposure to bovine leukemia virus, a cancer-causing cow virus, found in the milk of nearly every dairy herd in the United States?
The industry pointed out that some women without breast cancer harbored the virus, too. Indeed, the virus was also found in the tissues of 29% of women who did not have breast cancer—to which the researchers replied: yet.
It can take decades before a breast tumor can be picked up by mammography. So, even though they’re harboring this virus in their breast, and feel perfectly fine, the cancer may still be on its way. That’s how other cancer-causing delta retroviruses appear to work. These viruses can make proteins that interfere with our DNA repair mechanisms. Infected cells are then more susceptible to carcinogens, and slowly accumulate mutations over time. Therefore, the evidence of BLV in normal breast tissues, prior to malignant and premalignant changes, would be expected. Kind of like what you see with cervical cancer, in which the causative virus is not just found in the cancerous tissue, but also the precancerous tissue, and the normal tissue surrounding the malignant tumor.
If bovine leukemia virus is really causing thousands of cases of breast cancer every year, then, hey, since it’s a retrovirus, maybe some of the antiretroviral therapies (like some of the AIDS drugs) may be able to counter the virus—but, best to not get infected in the first place.
The cattle industry appeared more concerned about “consumer confidence” than consumer cancer. “A public relations brouhaha”—concerned that they might actually be forced to control these diseases in dairy cattle, and how the public would perceive it.
What would control look like? Well, bovine leukemia virus is a blood-borne virus. Wait a second; then how’s it spread? Is Bessie sharing dirty needles? Yes! Blood-contaminated needles, and saws, and gougers, pliers, taggers, knives, and tongs that they don’t disinfect between animals. So, if you’re gouging or sawing at their heads instead of burning, they’re “likely to drive blood into the next animal.” Or, when you’re sticking your arm into her rectum for artificial insemination, it’s not “uncommon for [there to be] rectal bleeding,” and then, they just go from one cow to the next.
More than 20 countries have successfully eradicated bovine leukemia virus from their herds by changing their practices—whereas in the U.S., it remains an epidemic, in part because we’re not cleaning and disinfecting blood-contaminated equipment for things like “supernumerary teat removal.” See, “extra teats detracts from the beauty of the cow.” So, “gently pull…[it] from the udder and cut [it off] with a pair of scissors.” Just make sure you clean those scissors. Otherwise, you could be spreading bovine leukemia virus from calf to calf, and ultimately into someone’s breakfast, lunch, or dinner. Of course, you could just not slice off their teats at all. But then, how would you improve the appearance of their udders?
Please consider volunteering to help out on the site.
- G C Buehring, H M Shen, H M Jensen, D L Jin, M Hudes, G Block. Exposure to Bovine Leukemia Virus Is Associated with Breast Cancer: A Case-Control Study. PLoS One. 2015 Sep 2;10(9):e0134304.
- (Author unknown) Bovine Leukosis Virus (BLV) on U.S. Dairy Operations, 2007.Veterinary ServicesCenters for Epidemiology and Animal Health. APHIS Info Sheet.
- P C Bartlett, L M Sordillo, T M Byrem, B Norby, D L Grooms, C L Swenson, J Zalucha, R J Erskine. Options for the control of bovine leukemia virus in dairy cattle. J Am Vet Med Assoc. 2014 Apr 15;244(8):914-22.
- (Author unknown) Bovine Leukosis Virus Background and Best Management Practices. New York State Cattle Health Assurance Program Brochure.
- C.M. Burns, Extension Assistant, Veterinary Science, Penn State University. Calves/Young Stock Removing extra teats. Dairy Connection, Vol. 9, No. 4, December 1999. (no longer available online)
- Skjervold, H. Supernumerary Teats in Cattle. Institute of Animal Breeding and Genetics, Agricultural College of Norway, (1959), 71-74.
- AGRI-VIEW. Research links bovine leukosis, breast cancer.
- Extension.org. Bovine Leukosis Virus. Nov 2, 2015
Image thanks to Roswell Park via flickr
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
What was the response to the revelation that as many as 37% of breast cancer cases may be attributable to exposure to bovine leukemia virus, a cancer-causing cow virus, found in the milk of nearly every dairy herd in the United States?
The industry pointed out that some women without breast cancer harbored the virus, too. Indeed, the virus was also found in the tissues of 29% of women who did not have breast cancer—to which the researchers replied: yet.
It can take decades before a breast tumor can be picked up by mammography. So, even though they’re harboring this virus in their breast, and feel perfectly fine, the cancer may still be on its way. That’s how other cancer-causing delta retroviruses appear to work. These viruses can make proteins that interfere with our DNA repair mechanisms. Infected cells are then more susceptible to carcinogens, and slowly accumulate mutations over time. Therefore, the evidence of BLV in normal breast tissues, prior to malignant and premalignant changes, would be expected. Kind of like what you see with cervical cancer, in which the causative virus is not just found in the cancerous tissue, but also the precancerous tissue, and the normal tissue surrounding the malignant tumor.
If bovine leukemia virus is really causing thousands of cases of breast cancer every year, then, hey, since it’s a retrovirus, maybe some of the antiretroviral therapies (like some of the AIDS drugs) may be able to counter the virus—but, best to not get infected in the first place.
The cattle industry appeared more concerned about “consumer confidence” than consumer cancer. “A public relations brouhaha”—concerned that they might actually be forced to control these diseases in dairy cattle, and how the public would perceive it.
What would control look like? Well, bovine leukemia virus is a blood-borne virus. Wait a second; then how’s it spread? Is Bessie sharing dirty needles? Yes! Blood-contaminated needles, and saws, and gougers, pliers, taggers, knives, and tongs that they don’t disinfect between animals. So, if you’re gouging or sawing at their heads instead of burning, they’re “likely to drive blood into the next animal.” Or, when you’re sticking your arm into her rectum for artificial insemination, it’s not “uncommon for [there to be] rectal bleeding,” and then, they just go from one cow to the next.
More than 20 countries have successfully eradicated bovine leukemia virus from their herds by changing their practices—whereas in the U.S., it remains an epidemic, in part because we’re not cleaning and disinfecting blood-contaminated equipment for things like “supernumerary teat removal.” See, “extra teats detracts from the beauty of the cow.” So, “gently pull…[it] from the udder and cut [it off] with a pair of scissors.” Just make sure you clean those scissors. Otherwise, you could be spreading bovine leukemia virus from calf to calf, and ultimately into someone’s breakfast, lunch, or dinner. Of course, you could just not slice off their teats at all. But then, how would you improve the appearance of their udders?
Please consider volunteering to help out on the site.
- G C Buehring, H M Shen, H M Jensen, D L Jin, M Hudes, G Block. Exposure to Bovine Leukemia Virus Is Associated with Breast Cancer: A Case-Control Study. PLoS One. 2015 Sep 2;10(9):e0134304.
- (Author unknown) Bovine Leukosis Virus (BLV) on U.S. Dairy Operations, 2007.Veterinary ServicesCenters for Epidemiology and Animal Health. APHIS Info Sheet.
- P C Bartlett, L M Sordillo, T M Byrem, B Norby, D L Grooms, C L Swenson, J Zalucha, R J Erskine. Options for the control of bovine leukemia virus in dairy cattle. J Am Vet Med Assoc. 2014 Apr 15;244(8):914-22.
- (Author unknown) Bovine Leukosis Virus Background and Best Management Practices. New York State Cattle Health Assurance Program Brochure.
- C.M. Burns, Extension Assistant, Veterinary Science, Penn State University. Calves/Young Stock Removing extra teats. Dairy Connection, Vol. 9, No. 4, December 1999. (no longer available online)
- Skjervold, H. Supernumerary Teats in Cattle. Institute of Animal Breeding and Genetics, Agricultural College of Norway, (1959), 71-74.
- AGRI-VIEW. Research links bovine leukosis, breast cancer.
- Extension.org. Bovine Leukosis Virus. Nov 2, 2015
Image thanks to Roswell Park via flickr
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Industry Response to Bovine Leukemia Virus in Breast Cancer
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Content URLDoctor's Note
Up to 37 percent of breast cancer cases are attributable to exposure to bovine leukemia virus? See The Role of Bovine Leukemia Virus in Breast Cancer and Is Bovine Leukemia Virus in Milk Infectious?.
The meat and dairy industries’ intransigence in the face of a human health threat reminds me of the antibiotics and steroids issues—continuing to place the public at risk to save a few bucks. See, for example, Antibiotics: Agribusinesses’ Pound of Flesh and Zeranol Use in Meat and Breast Cancer.
2022 Update: I just released two new videos on BLV. Check out Bovine Leukemia Virus as a Cause of Breast Cancer and Breast Cancer and the Bovine Leukemia Virus in Meat and Dairy.
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