Unless you’ve been living under a rock, you undoubtedly heard the media blast on Monday that consuming processed meats – and “probably” red meat itself – causes an increased risk or cancer. Talking heads, newspapers, and the Internet were breathless with the news. Here’s an example from The Washington Post:
The WHO findings were drafted by a panel of 22 international experts who reviewed decades of research on the link between red meat, processed meats and cancer. The panel reviewed animal experiments, studies of human diet and health, and cell processes that could explain how red meat might cause cancer.
And this from Yahoo News:
Each 50-gram (1.8-ounce) portion of processed meat eaten daily increases the risk of colorectal cancer by 18 percent, the agency estimated.
A 50-gram portion would be the equivalent of eating one hot dog or two slices of bacon. Americans eat about 21.7 grams of processed pork per day, according to a 2011 National Health and Nutrition Examination Survey.
The news reports are referring to a World Health Organization study that was drafted by a panel of 22 international experts who reviewed decades of research on the link between red meat, processed meats and cancer. The panel reviewed animal experiments, studies of human diet and health, and cell processes that could explain how red meat might cause cancer.
So what does that mean – an 18 percent increase in colorectal cancer risk? Sounds scary, right? Blogger Da Tech Guy is skeptical:
Right now a lot of lawyers are licking their chops and a lot of members of the food Gestapo are preparing to demand changes in school heath programs, school diets etc etc and I can feel the sheer panic among shoppers at Whole Foods from here.
And the reason why this is coming? Well there are two:
- Americans are really ignorant about math
- What are the actual odds of getting colorectal cancer?
The American Cancer Society, on its website, calculates the lifetime risk of developing or dying from cancer. The lifetime risk of developing or dying from cancer refers to the chance a person has, over the course of his or her lifetime (from birth to death), of being diagnosed with or dying from cancer. The risk is expressed both in terms of a percentage and as odds.
The risk for men of developing colorectal cancer during their lifetime is 4.84 percent. Put another way, 1 out of every 26 men in the United States will develop this type of cancer during his lifetime. The risk for men of dying as a result of colorectal cancer is 2.04 percent or 1 out of every 49.
What if he eats a hot dog or two slices of bacon every day? Most people (including journalists, apparently) would say his risk of contracting colorectal cancer would increase by 18 percentage points from 4.84 percent to 22.84 percent. Right?
Wrong. My Lincoln Elementary School math teacher Mrs. Buckley would write the words “of” and “by” on the chalkboard, then write a giant “X” over them. “Multiplication!” she would tell us. “These words in a math problem mean multiplication!”
A risk of 4.84% increased by 18% is 5.71%, a difference of only 0.87%. This makes headlines?
Back to Da Tech Guy:
In other words, if this study is absolutely positively spot on correct, eating that hot dog every single day for your entire life raises your odds of catching colorectal cancer by nearly, but not quite….1%.
Now when you put it that way, if you told a guy that giving up bacon decreases your odds of getting cancer by less that 1% most people would decide those odds aren’t worth panicking over and would rightly consider such panic as idiotic.
To be fair, there is absolutely nothing wrong if person decides that 1% increase warrants decreasing one’s intake of processed meats, if an individual thinks the increased risk isn’t worth it it’s their life and their choice to make.
But if you do make that choice do so on the actual evidence not due to panic and deception.
I think I’ll keep eating – and enjoying – my bacon.
Further Reading:
- The Washington Post – “Hot Dogs, Bacon and other Processed Meats Cause Cancer, World Health Organization Declares”
- Yahoo News – Bacon and other Processed Meats Can Cause Cancer, Experts Say
- World Health Organization – Q&A on the Carcinogenicity of the Consumption of Red Meat and Processed Meat
- Da Tech Guy – Bacon Panic + Poor Math Skills = Easy Money
