Unless you’ve been living under a rock, you would have read the headlines and stories and heard the reports exploding over the “WHO says red meat causes cancer” story last week.
Vegans were smug. Paleo people went on the attack. Virtually everyone voiced an opinion on it.
For this reason, I’ll refrain from voicing my own opinion on the matter (frequent readers will know my opinion anyway).
So my aim in this post is to present the facts, and let the reader use his/her own judgment and decide on a course of action. So here we go.
What did the WHO really say?
The WHO only published a 1.5-page summary of their findings (yes, this whole mess was caused by a 1.5 page summary). The full research won’t be published for a while.
The summary classified processed meats as a Group 1 Carcinogen (causes cancer) and red meat as Group 2A (probably causes cancer).
The studies were “observational”.
The studies looked at the association between meat consumption and colorectal cancer (not all cancer).
What’s the real risk we’re talking about here?
The report says that eating processed meats increases your risk of colorectal cancer by 17%.
This sounds like a lot, until you realize that this means that your risk goes from 5.5% (for someone who doesn’t eat any meat) to… wait for it… 6.6% for those who eat processed meat several times a day every day (read more).
In some of the other research used in the WHO report, eating processed and cured meats increases our chance of getting colorectal cancer by 1 in 33,000 (read more).
Numerous other studies have shown different results: many have shown that eating red meat REDUCES risk of colon cancer but INCREASES risk of rectal cancer (read more).
Other studies have shown no difference in mortality rates between fresh meat consumers and non-meat consumers (read more)
How strong is the evidence anyway?
By scientific standards (not my opinion), the evidence is weak: the types of studies used were “observational”, designed to look for “association” and not “causation” (vs. studies considered to be robust, such as randomized controlled trials, which are designed to look for cause-effect).
In other words, the studies observed people, asked them about their diet habits, and collected and analyzed the data.
Such studies are usually prone to “confounding factors” and “healthy user bias”: people who avoid meat tend to live more healthy lives anyway – they exercise more, don’t smoke, drink less, etc. So there is really no way to know the real cause-effect relationship.
The studies didn’t distinguish at all between “good quality meat” and “bad quality meat”: is it the meat that increases the risk of cancer? Or is it the hormones, antibiotics, and pesticides in the meat? Or meat from animals fed genetically modified corn and soy?
Other studies have shown “no relationship between grass-fed meat and mortality or cancer” and only a modest relationship for processed meats after significantly high consumption (read more).
So what else is Group 1 Carcinogen?
Here are some examples:
Estrogen therapy (post menopausal)
Outdoor air pollution (yes, the air you breathe)
Second hand tobacco smoke
Think of the dose-response: risk is related to how much your exposure is. For example: eating bacon 3 times a week vs. having a drink daily, or taking oral contraceptives daily.
What’s in Group 2A then?
Again, here are some examples:
Glyphosate (herbicide sprayed on almost every plant you eat)
Wood burning (fireplace)
Again, think dose: eating red meat 3x per week vs. eating vegetables 3x per day. Unless you’re eating organic all the time, you’re ingesting Glyphosate 3x a day.
(If you’re interested in the full lists, you can find them here).
Some additional thoughts to leave you with
Completely avoiding Group 1 and Group 2A essentially means a “true” caveman lifestyle, minus the hunting.
If you chose to continue to eat red meat, make sure that you prioritize the quality of the meat (grass-fed and organic)
If you chose to eat processed meats, again make sure there are no additives (nitrites or preservatives)
Red meat continues to be a primary source of essential nutrients, especially Vitamin B12, iron and zinc, all common deficiencies
High Performance Coach