Why bacon and deli meat are treated differently from steak.
6 min read
The risk isn't the same for all meat. Processed meat has stronger evidence than red meat.
In 2015 the World Health Organization's cancer agency (IARC) placed processed meat in Group 1, 'carcinogenic to humans,' because there was sufficient evidence it causes colorectal cancer. Red meat went in Group 2A, 'probably carcinogenic,' because the evidence in humans was more limited. IARC estimated that each 50 grams of processed meat eaten every day was linked to an 18% higher relative risk of colorectal cancer. That is a daily-eating estimate, not the risk from an occasional serving.
Red meat means all mammal muscle meat: beef, veal, pork, lamb, mutton, horse and goat. Processed meat means meat changed by salting, curing, fermenting or smoking to improve flavor or keep it longer. This applies to poultry too: fresh chicken and turkey are not red meat, but cured turkey bacon, smoked turkey and many packaged chicken or turkey deli slices can still count as processed meat.
AICR's recommendation follows the evidence: eat no more than moderate amounts of red meat (12 to 18 ounces a week), and little, if any, processed meat. It says both are causes of colorectal cancer. The American Cancer Society also says to limit or avoid both.
So this is not 'never eat steak.' It is a limit on red meat and a strong reason to eat little, if any, processed meat.
18%
higher relative colorectal cancer risk for each 50 g of processed meat eaten daily
IARC, 2015 (22 experts, 10 countries)
Group 1
IARC's classification for processed meat
IARC
Group 2A
IARC's classification for red meat ('probably carcinogenic')
IARC
12 to 18 oz
a week of red meat is AICR's limit
AICR
IARC's examples: hot dogs, ham, sausages, corned beef, beef jerky, biltong, canned meat, and meat-based preparations and sauces. Bacon and deli meats such as salami are in the same group. Poultry can be processed meat too: cured turkey bacon, smoked turkey, chicken sausage and many packaged deli slices count if they are salted, cured, smoked or made with preservatives.
The 18% is a relative increase. It means a person's risk is 18% higher than it would have been, not that 18 in 100 people get cancer. IARC's group 1 label describes how strong the evidence is that something can cause cancer, not how large the risk is. For perspective, if a baseline risk were 5%, an 18% relative increase would bring it to about 5.9%, not 23%.
The size of the effect depends on how much and how often. Daily processed meat adds up. An occasional hot dog at a cookout is a very different thing from a daily deli sandwich. Even so, research hasn't established a completely risk-free amount, and AICR recommends eating little, if any, processed meat.
It's about three modest portions of red meat a week, each in the 4 to 6 ounce range, rather than one large steak every night. It's a guideline, not a line where one more ounce suddenly becomes dangerous.
| If you usually have | Try |
|---|---|
| A deli sandwich at lunch | A hummus and vegetable wrap, or the Mediterranean chickpea salad jar |
| Bacon or sausage at breakfast | Veggie egg scramble, overnight oats, or banana oat pancakes |
| Hot dogs or sausage for dinner | Chicken, white bean and kale stew, or a turkey stir-fry made with fresh turkey |
| A beef-heavy dinner most nights | Fish twice a week and a bean or lentil dinner twice a week |
Check labels on packaged poultry. Smoked, cured and deli-style chicken or turkey can still be processed meat.
Myth
Red meat and processed meat carry the same risk.
What research says
IARC puts them in different groups because the evidence for processed meat is stronger. AICR allows a moderate amount of red meat and says little, if any, processed meat.
IARC; AICR
Myth
Group 1 means it's as dangerous as smoking.
What research says
Group 1 means there is sufficient evidence that processed meat can cause cancer in humans. It does not mean processed meat carries the same level of risk as smoking. IARC classifications describe the strength of the evidence, not how dangerous an exposure is at a particular level.
IARC classification
Myth
Jerky and canned meat aren't 'real' processed meat.
What research says
IARC lists beef jerky, biltong and canned meat among processed meats.
IARC
Myth
Turkey and chicken deli meat is the same as fresh poultry.
What research says
Fresh chicken and turkey are not red meat, but packaged turkey or chicken that is cured, smoked or made with preservatives can still be processed meat. Check labels.
AICR
Myth
Red meat means only beef.
What research says
IARC's definition covers all mammalian muscle meat: beef, veal, pork, lamb, mutton, horse and goat.
IARC
Audit your fridge and freezer
Write down every processed meat you buy regularly: bacon, deli meat, sausage, hot dogs, jerky.
Cut your most frequent one
Pick the processed meat you eat most often and replace it with a meal-plan lunch or breakfast at least twice this week.
Set a red meat limit
Plan no more than about three portions of red meat for the week (12 to 18 ounces total).
Make an easy swap ready
Cook an extra chicken breast on Sunday and slice it for sandwiches instead of buying deli meat.
- IARC (World Health Organization): Press release 240: IARC Monographs evaluate consumption of red meat and processed meat (Oct 2015)
- American Institute for Cancer Research: Cancer prevention recommendations: red and processed meat
- American Cancer Society: Guideline for Diet and Physical Activity for Cancer Prevention