© C. C. Chapman/Flickr
BY GAIL BARNES SUSTAINABILITY SPECIALIST
On Monday this week the internet and social media erupted because of a monograph that had been published by the WHO’s International Agency for Research on Cancer (IARC). Headlines such as “processed meats rank alongside smoking as cancer causes – WHO” both misrepresented the IARC’s conclusions and added fuel to the flames of consumer concerns.
Below is the IARC’s monograph in full, as well as the WHO’s subsequent response to the outpouring of questions and requests for clarification from consumers:
Lyon, France, 26 October 2015 – The International Agency for Research on Cancer (IARC), the cancer agency of the World Health Organization, has evaluated the carcinogenicity of the consumption of red meat and processed meat. Red meat After thoroughly reviewing the accumulated scientific literature, a working group of 22 experts from ten countries convened by the IARC Monographs Programme classified the consumption of red meat as probably carcinogenic to humans (group 2A), based on limited evidence that the consumption of red meat causes cancer in humans and strong mechanistic evidence supporting a carcinogenic effect. This association was observed mainly for colorectal cancer, but associations were also seen for pancreatic cancer and prostate cancer. Processed meat Processed meat was classified as carcinogenic to humans (group 1), based on sufficient evidence in humans that the consumption of processed meat causes colorectal cancer. Meat consumption and its effects The consumption of meat varies greatly between countries, with from a few percent up to 100% of people eating red meat, depending on the country, and somewhat lower proportions eating processed meat. The experts concluded that each 50g portion of processed meat eaten daily increases the risk of colorectal cancer by 18%. “For an individual, the risk of developing colorectal cancer because of their consumption of processed meat remains small, but this risk increases with the amount of meat consumed,” says Dr Kurt Straif, head of the IARC Monographs Programme. “In view of the large number of people who consume processed meat, the global impact on cancer incidence is of public health importance.” The IARC Working Group considered more than 800 studies that investigated associations of more than a dozen types of cancer with the consumption of red meat or processed meat in many countries and populations with diverse diets. The most influential evidence came from large prospective cohort studies conducted over the past 20 years.
Lyon, France, 26 October 2015 – The International Agency for Research on Cancer (IARC), the cancer agency of the World Health Organization, has evaluated the carcinogenicity of the consumption of red meat and processed meat.
Red meat
After thoroughly reviewing the accumulated scientific literature, a working group of 22 experts from ten countries convened by the IARC Monographs Programme classified the consumption of red meat as probably carcinogenic to humans (group 2A), based on limited evidence that the consumption of red meat causes cancer in humans and strong mechanistic evidence supporting a carcinogenic effect.
This association was observed mainly for colorectal cancer, but associations were also seen for pancreatic cancer and prostate cancer.
Processed meat
Processed meat was classified as carcinogenic to humans (group 1), based on sufficient evidence in humans that the consumption of processed meat causes colorectal cancer.
Meat consumption and its effects
The consumption of meat varies greatly between countries, with from a few percent up to 100% of people eating red meat, depending on the country, and somewhat lower proportions eating processed meat.
The experts concluded that each 50g portion of processed meat eaten daily increases the risk of colorectal cancer by 18%.
“For an individual, the risk of developing colorectal cancer because of their consumption of processed meat remains small, but this risk increases with the amount of meat consumed,” says Dr Kurt Straif, head of the IARC Monographs Programme. “In view of the large number of people who consume processed meat, the global impact on cancer incidence is of public health importance.”
The IARC Working Group considered more than 800 studies that investigated associations of more than a dozen types of cancer with the consumption of red meat or processed meat in many countries and populations with diverse diets. The most influential evidence came from large prospective cohort studies conducted over the past 20 years.
In the light of global media attention and consumer concern and requests for clarification, on the 29 October the WHO posted this statement on their website:
WHO has received a number of queries, expressions of concern and requests for clarification following the publication of a report from the International Agency for Research on Cancer (IARC) relating to processed meat and colorectal cancer. IARC was established 50 years ago through a resolution of the World Health Assembly as a functionally independent cancer agency under the auspices of WHO. Its programme of work is approved and financed by its participating states. 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 but indicates that reducing consumption of these products can reduce the risk of colorectal cancer.
WHO has received a number of queries, expressions of concern and requests for clarification following the publication of a report from the International Agency for Research on Cancer (IARC) relating to processed meat and colorectal cancer.
IARC was established 50 years ago through a resolution of the World Health Assembly as a functionally independent cancer agency under the auspices of WHO. Its programme of work is approved and financed by its participating states.
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 but indicates that reducing consumption of these products can reduce the risk of colorectal cancer.
Important to note is this quote from the IARC monograph, “For an individual, the risk of developing colorectal cancer because of their consumption of processed meat remains small, but this risk increases with the amount of meat consumed.”
The last sentence in the WHO post is most pertinent, namely that the IARC review, “does not ask people to stop eating processed meats but indicates that reducing consumption of these products can reduce the risk of colorectal cancer.”
The source of the link to cancer
The link between processed meat and colorectal cancer may start with an iron-based chemical called heme, found in red meat. Heme iron has been reported to cause the formation of carcinogenic N-nitroso compounds, and also result in the formation of cytotoxic and genotoxic aldehydes.
The nitrates and nitrites used to preserve processed meats also turn into N-nitroso compounds. Grilling, frying, or otherwise cooking the meat at high-temperatures may create other cancer-causing compounds.
Advances in flexible packaging may offer a silver lining
The silver lining for processors deciding on how to respond to what could be declining sales as a result of consumer health concerns over processed meats, is that advances in flexible packaging materials have translated into being able to keep processed meats fresher longer. As a result of the superior barrier properties of these films, significantly lower amounts of salt and other preservatives are required.
© FoodBev Media Ltd 2024