This week the World Health Organisation’s International Agency for Research (IARC) on Cancer classified processed meats – such as bacon, ham and sausages – in the category of group 1 carcinogens due to its causal link with colorectal or colon cancer.
This category is used when there is sufficient evidence of carcinogenicity in humans. The evaluation is usually based on epidemiological studies showing development of cancer in exposed humans.
The WHO findings were drafted by a panel of 22 international experts from 10 countries who reviewed decades of research on the link between red meat, processed meats and cancer.
The agency placed red meat in group 2A, meaning that it was “probably carcinogenic to humans”.
The experts concluded that each 50 gram portion of processed meat (roughly equivalent to a hot dog or a little less than two pieces of bacon or a few slices of smoked turkey) eaten daily increases the risk of colorectal cancer by 18%.
Processed meat is thought to have a higher cancer risk than red meat because carcinogenic chemicals, such as the N-nitroso compound and polycyclic aromatic hydrocarbons, can form during smoking or curing and when salt or preservatives are added.
A summary of the final evaluations is available online in The Lancet Oncology, and the detailed assessments will be published as Volume 114 of the IARC Monographs.
There is sure to be a response from the $95-billion US beef industry.