5 things: What the findings on red, processed meat and cancer really mean

Now that the International Agency for Research on Cancer has confirmed a link between processed meat and colorectal cancer, you might be reconsidering what's in your lunch bag. We've rounded up what you need to know before eating your next meal.

Cancer risk pales compared to smoking

Bacon, ham, sausage and other processed meats are connected to a higher risk for colorectal cancer, researchers have found. (CBC)

Now that the International Agency for Research on Cancer has confirmed a link between processed meat and colorectal cancer, you might be reconsidering what's in your lunch bag.

But although the fact that processed meats like ham and sausage have been classified in the same risk category as tobacco, it does not mean they're as likely to cause cancer as smoking.

Here's what you should know before you eat your next meal:

1. Processed meat definitely boosts risk of colorectal cancer

The International Agency for Research on Cancer found a definitive link between eating processed meat and developing colorectal cancer, as processing causes chemicals linked to cancer. The working group of 22 experts feels so confident in its findings that it has classified processed meats in the same category as tobacco and asbestos — a substance that definitively causes cancer.

That's likely because the salting and curing of meat creates cancer-causing chemicals like polycyclic aromatic hydrocarbons (PAHs), according to the IARC's article published in the medical journal the Lancet Oncology Monday.

2. Level of risk depends on how much processed meat you eat

Eating 50 grams — two slices of bacon — each day boosts your risk of colorectal cancer by 18 per cent, according to the findings. The researchers found a "statistically significant dose-response relationship" between the consumption of processed meats and colorectal cancer.

"These findings further support current public health recommendations to limit intake of meat," Dr. Christopher Wild, the IARC's director said Monday.

But the agency doesn't say how much meat is safe; they're leaving that up to governments to recommend.

3. Eating processed meat not as dangerous as smoking

To put the findings in perspective, it's important to understand that about seven per cent of Canadian men and six per cent of Canadian women will develop colorectal cancer in their lifetimes, according to the Canadian Cancer Society.

So, starting from there, an average Canadian man who eats a 50-gram serving of ham each day boosts his risk of getting colorectal cancer to about 8.26 per cent — an increase of 18 per cent from a person's baseline risk. And, theoretically, it would be a little lower since the baseline figure of seven per cent would already include people who eat processed meat.

Other risks that can predispose someone to colon cancer include having inflammatory bowel disease, a family history of the illness, age, smoking and certain genetic conditions.

Smoking, on the other hand, increases someone's risk of developing lung cancer by about 25 times — or 2,500 per cent, according to Cancer Research UK.

4. Jury's still out on red meat — and it depends how it's cooked

While the IARC researchers are satisfied of the link between processed meat and cancer, they are less confident about the role red meat plays in cancer risk.

"Chance, bias and confounding could not be ruled out ... since no clear association was seen in several of the high quality studies and [the influence] from other diet and lifestyle risk is difficult to exclude."

Researchers ruled red meat as "possibly carcinogenic" — and found that the way in which meat is cooked could increase the amount of cancer-causing agents in it. High-heat cooking like barbecuing is more likely to produce higher amounts of carcinogenic chemicals, like polycyclic aromatic hydrocarbons, the Lancet article says.

5. 34,000 cancer deaths each year could be blamed on processed meat, researchers say

The Global Burden of Disease Project suggested that 34,000 global cancer deaths each year are connected to diets rich in processed meat, according to the IARC.

On the other hand, about one million cancer deaths are attributed to smoking and 600,000 due to drinking alcohol, Reuters reports.

6. You don't have to give up cold cuts, hot dogs for good

Risk of bowel cancer from processed and other meats is small, but increases with consumption, agency says 5:26

Corrections

  • An earlier version of this story said that the average man who eats a 50-gram serving of ham each day boosts his risk of getting colorectal cancer to about 12 per cent, when, in fact, it would 8.26 per cent.
    Oct 26, 2015 1:15 PM ET

Comments

To encourage thoughtful and respectful conversations, first and last names will appear with each submission to CBC/Radio-Canada's online communities (except in children and youth-oriented communities). Pseudonyms will no longer be permitted.

By submitting a comment, you accept that CBC has the right to reproduce and publish that comment in whole or in part, in any manner CBC chooses. Please note that CBC does not endorse the opinions expressed in comments. Comments on this story are moderated according to our Submission Guidelines. Comments are welcome while open. We reserve the right to close comments at any time.