Courtesy of Vegan Street, where it has over 750 likes and 630 shares.  This comes from a study, which the World Health Organization (WHO) recently cited to label processed meats like bacon and sausage as a carcinogen, and red meat as probable carcinogens.  The media went wild with this, and headlines ranged from cautious warnings to outright fear mongering about the dangers of bacon, like this meme.  Lost in most of this was the context and reality of the data.

Before we get into the study, it should be noted that there is debate over the efficacy of many food studies, which is acknowledged by researchers.  This study relied on what’s known as food frequency questionnaires to determine people’s diets.  Can you accurately recall what you ate last week?  How about last month?  These questionnaires often require people to recall their diets for the last year, which can understandably lead to all sorts of accuracy issues.  (Did I eat red meat 3 times a week or 5?!) In addition, red and processed meat eaters are more likely to engage in unhealthy lifestyles, eat more fast food and less vegetables.  Some might eat grass-fed steak along with piles of broccoli and go for a hike, but they’re probably in the minority.  Researchers try to control for these things, but the data can still be questioned.  That being said, these studies are often the best scientists can go on, so in this case we’ll take the WHO data as gospel and proceed.

Carcinogen Groups

This meme mentions that bacon has the same cancer risks as cigarettes, which is extremely misleading, as we’ll see.  The International Agency for the Research on Cancer (IARC), which is part of the WHO, classifies carcinogens into several groups.

• Group 1– Established carcinogens
  • Examples include asbestos, plutonium, cigarettes, alcohol, outdoor pollution, UV and solar radiation, contraceptives, Chinese-style salted fish, and now processed meats.
• Group 2A– Probable carcinogens
  • Examples include glyphosates, certain insecticides, burning wood, and red meat.
• Group 2B– Possible carcinogens
  • Examples include half of God’s green earth!  Things like coffee, cell phones and pickled vegetables are found here, and if you’ve ever thought “everything causes cancer” you wouldn’t be far off.
• Group 3– Not classified either way
  • Examples include the other half of God’s green earth.
• Group 4- Probably not carcinogenic
  • The IARC lists only 1 thing in this category; caprolactam, which is used in making nylon.  However, apparently it causes burning of the eyes and throat, so it’s not exactly manna from heaven.

It should be clear from this list that the grouping isn’t particularly relevant when deciding if something is dangerous or not.  A nuclear bomb detonation, cigarettes and contraceptives are all in Group 1, but have vastly different impacts on cancer.  The groupings are only viewing the strength of evidence, not the level of danger.  Now that we have the context of this, let’s move on to the dangers of bacon.

Processed Meats and Cancer

This study’s results dealt primarily with colorectal cancer, and determined eating 50 grams of processed meats everyday (a bit more than 2 slices of bacon) elevates one’s risk by 18%.  This might sounds substantial, but we have to keep it in context.  Colorectal cancer is fairly rare, the lifetime risk for 50 year old adults is only 1.8%.  Increasing that risk by 18% means one’s risk of colorectal cancer goes up to about 2.1%, which is likely not enough to get most bacon lovers across the world to shelve their habit.  However, it should be noted that those with family histories of this cancer already have up to a 7% chance of getting it, so processed meats could impact them more significantly.

As far as other types of cancers, this study does mention that there are positive correlations with pancreatic, prostate and stomach cancers, but the evidence wasn’t as strong, and it’s not clear to what degree.

Comparison to Cigarettes

If bacon can increase your risk of colorectal cancer by 18%, how do cigarettes compare with lung cancer?  Try 2500%!  Yes, smokers are over 25 times more likely to get lung cancer, as well as increased levels of almost every other type of cancer.  In other words, there is no comparison between the two.  Bacon does not carry the same cancer risk as cigarettes, nor is it the same as asbestos or nuclear fallout.

Other Useful Information on Red Meat and Cancer

• The study mentions that cooking meat under high heat (searing, grilling, pan frying, etc.) increases carcinogens, as does eating “well done” meat.  Admittedly, this is how many eat meat, but gentler methods like slow cooking, braising and marinating reduce these risks.
• Processing meat by curing, smoking and other methods may add carcinogens.  While it’s nothing like smoking a pack a day, it’s probably best not to base one’s entire diet around hot dogs.
• The study confirms that red meat “contains high biological-value proteins and important micronutrients such as B vitamins, iron…and zinc.”
• Eating green vegetables with meat can reduce the carcinogenic effects of meat
• Eating antioxidants with meat (i.e. coffee, dark chocolate, berries) can inhibit carcinogen formation
• Grass-fed and pasture raised animals are likely better, as the animals eat a more nutritious diet, and their fat contains antioxidants like lutein, which reduces colon cancer in humans.

Twin Memes!

To Vegan Street’s credit, after some complaints they did put forth another meme (shown to the right) that’s not quite as misleading, but still relies on the ignorance of the viewer about carcinogen categories and absolute risk.  It currently only has about 1/10 the likes and shares of the first one.