I was carrying out a research for my project "Red Meat and Cancer" when I came across this question "How did the WHO conclude that red and processed meat causes cancer" and the following answer by Stephen Labit on quora.com. Please keep reading.


The WHO has come to the conclusion on the advice of its International  Agency for Research on Cancer, which assesses the best available  scientific evidence. - Processed meats do cause cancer - WHO - BBC News

So where did the International Agency for Research on Cancer get their data from? The full text of the assessments of the studies they looked through are here (Page on thelancet.com), but I summarized in note format below to make it easy:

On 22OCT2015, 22 scientists from 10 countries met at International Agency for Research on Cancer Monograph Working Group (or WG for short) assessed 800 studies that investigated association between  cancer - redmeat/processed meat consumption (the details of eval weights,  data discrimination, and links to individual studies in full text).

Meat consumption varies worldwide w/ some stats

Terms Defined:
Red meat refers to unprocessed mammalian muscle meat—for example,  beef, veal, pork, lamb, mutton, horse, or goat meat—including minced or  frozen meat; it is usually consumed cooked.

Processed meat refers to meat that has been transformed through  salting, curing, fermentation, smoking, or other processes to enhance  flavour or improve preservation.

Evidence assessed:
Positive associations w colorectal cancer was the concern of  majority of data from assessed studies (data also available on 15 other  types of cancer). Majority of WG concluded sufficient evidence in human  beings for carcinogenicity of consumption of processed meat and limited  evidence w red meat (since they could not rule out chance, bias, and  confounding w latter).

Inadequate evidence in experimental animals

Mechanistic evidence assessed as strong for red meat, moderate for processed meat.

WG classification:
Consumption of processed meat as “carcinogenic to humans” on  basis of sufficient evidence for colorectal cancer and positive  association w consumption of processed meat found for stomach cancer.

Consumption of red meat as “probably carcinogenic to humans” took  into consideration all relevant data, incl substantial positive  association between consumption of red meat and colorectal cancer and  the strong mechanistic evidence. Consumption of red meat also positively  associated w pancreatic and w prostate cancer.

My thoughts:
Calculated risk is the bottom line. Our bodies have natural  mechanisms to mitigate harm from the environment (to include our food),  so it's less of a matter of avoiding risk but staying informed of the  risks allows us to make effective decisions to control our fragility to  those risks.

I will certainly reduce the qty of processed meat I eat because  at the moment I do eat it frequently and in generous amounts (mmm  bacon...)

Thanks for reading!

If you enjoyed these notes, check out my other notes on a variety of other topics at http://Stephenlabit.com -- a repository of personal projects.


My conclusion. Red meat causes cancer. Avoid it as much as possible.