MADISON, Wisconsin––Just a week after the World Health Organization and International Agency for Cancer Research linked hot dog consumption to colorectal, pancreatic, and prostate cancers, Oscar Mayer is leaving town.
Oscar Mayer, for 132 years among the biggest names in hot dogs, known since 1936 for deploying a succession of custom-made “weinermobiles” to public events, on November 4, 2015 announced that it will close its headquarters and manufacturing facilities in Madison, Wisconsin, 96 years after relocating to Madison from Chicago.
A Kraft Foods subsidiary since 1981, Oscar Mayer is downsizing as part of a Kraft downsizing that includes closing facilities in California, Maryland, New York, Wisconsin, and Ontario, eliminating 2,600 jobs, following the August 2015 layoffs of 2,500 workers.
“The backdrop for all these changes is that Americans are becoming wary of processed foods,” reported Diane Bondareff of Associated Press. “For Oscar Mayer in particular, it doesn’t help that recent studies have linked processed meats to premature death and cancer.”
Oxford study confirms WHO warning of cancer risk from red meat
GENEVA, Switzerland; LYON, France, LIVERPOOL, U.K.––Less than a week after the World Health Organization and the International Agency of Cancer Research warned that eating red and processed meats markedly increases the risk that a person will contract colorectal, pancreatic, and prostate cancers, a major new University of Oxford study has confirmed several of the key points in the WHO and IACR warning.
The University of Oxford study “tracked the meat-eating habits of more than 500,000 British men and women aged 40 to 69,” summarized Yahoo.com health writer Korin Miller. “Participants who ate four servings of red meat a week were 42% more likely to develop colorectal cancer than those who had one serving or none at all. Participants who ate red meat at least twice a week were 18% more likely to develop colorectal cancer than vegetarians.”
The findings were presented on November 2, 2015 at the annual conference of the British National Cancer Research Institute, held in Liverpool, England.
Differing processed meat finding
“Surprisingly,” Miller added, the Oxford study “did not find a link between eating processed meats and an increased risk of colorectal cancer,” whereas WHO and the International Agency of Cancer Research reported that consuming an average of as little as 50 grams or two ounces of processed meat increases the risk that a person will contract cancer by about 18%.
Under intensive pressure from the beef and bacon industries, especially in the U.S., the World Health Organization and the International Agency of Cancer Research on October 29, 2015 “clarified” an October 26, 2015 warning that eating red meats and processed meats significantly increase the risk of the consumer contracting colorectal, pancreatic, and prostate cancers.
But the World Health Organization and International Agency of Cancer Research, a 50-year-old advisory body to WHO, did not retreat from the substance of their warning.
“Reducing consumption can reduce risk”
Said the WHO “clarification” statement, “IARC’s review confirms the recommendation in WHO’s 2002 Diet, nutrition and the prevention of chronic diseases report, which advised people to moderate consumption of preserved meat to reduce the risk of cancer. The latest IARC review does not ask people to stop eating processed meats,” WHO continued, “but indicates that reducing consumption of these products can reduce the risk of colorectal cancer.”
Concluded the WHO statement, “WHO has a standing group of experts who regularly evaluate the links between diet and disease. Early next year they will meet to begin looking at the public health implications of the latest science and the place of processed meat and red meat within the context of an overall healthy diet.”
The WHO/IARC warning identified red meat as “all mammalian muscle meat, including beef, veal, pork, lamb, mutton, horse, and goat.”
Processed meat was defined as “meat that has been transformed through salting, curing, fermentation, smoking, or other processes to enhance flavor or improve preservation. Most processed meats contain pork or beef,” WHO and IARC noted in a question-and-answer page posted online and distributed to media, “but processed meats may also contain other red meats, poultry, offal, or meat by-products such as blood.
“Examples of processed meat,” the WHO/IARC question-and-answer page offered, “include hot dogs (frankfurters), ham, sausages, corned beef, and biltong or beef jerky, as well as canned meat and meat-based preparations and sauces.”
Group 1 carcinogen
The October 26, 2015 WHO/IARC warning defined processed meat as a Group 1 carcinogen. This means that WHO and IARC consider the weight of scientific evidence demonstrating that processed meats cause cancer in humans to be strongly convincing. Among the best-known Group 1 carcinogens are tobacco and asbestos.
However, the WHO/IARC question-and-answer page clarified, “This does not mean that [all Group 1 carcinogens] are equally dangerous. The IARC classifications describe the strength of the scientific evidence about an agent being a cause of cancer, rather than assessing the level of risk.”
Continued the WHO/IARC question-and-answer page, “The strongest, but still limited, evidence for an association with eating red meat is for colorectal cancer. There is also evidence of links with pancreatic cancer and prostate cancer.
The IACR Working Group concluded that eating processed meat causes colorectal cancer. An association with stomach cancer was also seen, but the evidence is not conclusive.”
Comparing the risks from red and processed meats to the known risks from other carcinogens, the WHO/IACR question-and-answer page cited “recent estimates by the Global Burden of Disease Project, an independent academic research organization,” which found that “About 34,000 cancer deaths per year worldwide are attributable to diets high in processed meat.
“Eating red meat has not yet been established as a cause of cancer,” the WHO/IACR question-and-answer page continued. “However, if the reported associations were proven to be causal, the Global Burden of Disease Project has estimated that diets high in red meat could be responsible for 50,000 cancer deaths per year worldwide.
“These numbers contrast with about 1 million cancer deaths per year globally due to tobacco smoking, 600,000 per year due to alcohol consumption, and more than 200,000 per year due to air pollution.”
The University of Oxford and WHO/IACR warnings reinforce mounting evidence from earlier studies.
Among the most influential,” U.S. National Cancer Institute researchers reported in the March 23, 2009 edition of Annals of Internal Medicine that “High intakes of red or processed meat may increase the risk of mortality.”
Annals of Internal Medicine is a peer-reviewed journal published by the American Medical Association.
Similar U.S. findings
The National Cancer Institute researchers examined the relationship of diet and mortality among more than half a million middle-aged and elderly Americans from 1995 until the end of 2005. The participants, all between 52 and 71 years old, joined the study by completing a 124-question survey about their eating habits, distributed by the American Association of Retired Persons.
“Follow-up for vital status was performed by annual linkage of the cohort to the Social Security Administration Death Master File, and cause of death information was provided by follow-up searches of the National Death Index,” explained study authors Rashmi Sinha, Amanda J. Cross, Barry I. Graubard, Michael F. Leitzmann, and Arthur Schatzkin.
The authors corrected the findings to exclude the effects of smoking. The study examined many other potential variables affecting mortality, but none of the others appeared to have statistical significance approaching that of meat consumption–especially red and processed meat intake.
There were 47,976 male deaths and 23,276 female deaths among the study cohort of 322,263 men and 223,390 women.
“Red and processed meat intakes were associated with modest increases in total mortality, cancer mortality, and cardiovascular disease mortality,” Sinha et al found, as compared to the norms of the study group.
But the differences between the people who ate the most red and processed meat and those who ate the least were much greater. The 20% of men who ate the most red meat were 35% more likely to likely to die than the 20% who ate the least. The 20% of women who ate the most red meat were 43% more likely to likely to die than the 20% who ate the least. The differentials for the highest and lowest consumption of processed meat were 20% for men, 31% for women.
Deaths “could be prevented”
“Eleven percent of deaths in men and 16% of deaths in women could be prevented if people decreased their red meat consumption to the level of intake in the first quintile,” the study authors determined.
“Red meat intake was calculated using the frequency of consumption and portion size information of all types of beef and pork,” said the study, “and included bacon, beef, cold cuts, ham, hamburger, hotdogs, liver, pork, sausage, steak, and meats in foods such as pizza, chili, lasagna, and stew. Processed meat included bacon, red meat sausage, poultry sausage, luncheon meats, cold cuts, ham, regular hotdogs, and low-fat hotdogs made from poultry.”
“There are various mechanisms by which meat may be related to mortality,” Sinha et al explained. “In relation to cancer, meat is a source of several multisite carcinogens. Iron in red meat may increase oxidative damage and increase the formation of N-nitroso compounds. Furthermore, meat is a major source of saturated fat, which has been positively associated with breast and colorectal cancer. Elevated blood pressure has been shown to be positively associated with higher intakes of red and processed meat.”
The 2015 Oxford University, World Health Organization and the International Agency of Cancer Research publications did not evaluate the cancer risks and other health effects associated with consumption of poultry and fish.
Responding to the earlier National Cancer Institute findings, Harvard School of Public Health nutrition scientist Walter Willet recommended that, “It would be better to shift from red meat to white meat such as chicken and fish, which if anything is associated with lower mortality.”
But that is not what the study found.
Mortality among the 20% of the National Cancer Institute study cohort who ate the most poultry and fish was slightly lower than among those who ate the least, but the participants who ate the most poultry and fish tended to eat the least red meat.
“In general, those in the highest quintile of red meat intake tended to consume a slightly lower amount of white meat but a higher amount of processed meat compared with those in the lowest quintile,” the study reported.
“The data shows link between total meat & mortality”
“From Table 1 of the paper,” commented Burnham Institute for Medical Research biochemist Shi Huang, in a posting to Med Page Today, “it is shown that the group with the highest red meat intake consumed 119 grams [of all forms of meat] per kilogram of caloric intake. The data of total amount of all meat [consumed] for the group with the highest white meat intake is not shown, but my estimate based on the reported data for this group is 69 grams per kilogram of caloric intake.
“So, it seems that people who mostly eat white meat consumed [about half as much meat of all types] than people who eat red meat. The people with the highest intake of white meat have a lower risk of death than those with lowest intake, as reported. But those with low intake of white meat actually consume more red meat and total meat in general. The bottom line,” Huang concluded, is that “the data overall shows a link between total amount of meat and mortality. The color of meat is irrelevant.”
Vegetarians & vegans
The National Cancer Institute study did not separately investigate mortality among vegetarians, who in the middle-aged and elderly age brackets would be only about 2% of the U.S. population.
Suggested the WHO/IACR question-and-answer page, “Vegetarian diets and diets that include meat have different advantages and disadvantages for health. However, this evaluation did not directly compare health risks in vegetarians and people who eat meat. That type of comparison is difficult because these groups can be different in other ways besides their consumption of meat.”
Building on 2001 findings
The Oxford University, WHO/IACR data, and the National Cancer Institute findings all follow up and expand upon data presented in June 2001 by then-IACR nutrition division chief Elio Riboli, who now heads the School of Public Health at Imperial College, London.
Following the diets and cancer histories of 406,323 Europeans since 1993, Riboli and colleagues reported to the June 2001 European Conference on Nutrition and Cancer in Lyon, France that eating preserved meat products appeared to increase the risk of bowel cancer by 50%.