Has news of the declaration of processed meat as carcinogenic blown over?
One answer is: I got a really good deal on bacon the other day, validating my first thoughts about the report released Oct 25, 2015 from the World Health Organization that processed meats and maybe red meat are carcinogenic:
Woo-hoo, steak’ll be cheap now.
I do love a good rare hunk of rib steak, flash fried in a bit of butter, with a side of mushrooms and onions. Mmmm. Humans are omnivores and we’ve been eating red meat since, uhm, before we were human. Also, the designation of processed meats – not red meat – as carcinogenic suggested to me that it’s a consequence of processing, not the meat, that’s the greater risk. Finally, lots of things are carcinogenic, but it depends on how much you consume and how often you are exposed. (My first scientist’s segue: the details of the announcement dwelt on the types of cancer and the amount of consumption.¹)
After a bit of data diving, I wondered if this was a good story about the fun you could have with death statistics. Then I settled down and realized only a very small fraction of the population considers statistics fun. (If you are interested, here some details about the relative significance of processed meat in the grand scheme of risk factors for mortality.² )
Adventures in epidemiology aside, I started feeling, instead of thinking. The things that are on the same list as processed meat include asbestos, smoking, sunbathing. Many of us give a healthy respect to avoiding these things, perhaps because we’ve all known someone who has died of a cancer associated with exposure to one of them. The announcement should be taken seriously.
Can we rely on efficient capital markets to take care of us? Only if demand for processed meats fall so low that they are no longer cost effective to produce will the products disappear.
Or should society take a more proactive approach, protecting citizens from hazard and remove processed meat from our grocery shelves?
A fantastic business model would be a new approach to producing savoury, well-preserved meats that avoided the current, toxic processing. Problem is, do we know what that is? I’ve seen some reports³ that suggests it’s nitroamines (carcinogenic in many models 4) generated during high temperature cooking of meats, or maybe other compounds (certain aromatic hydrocarbons), or the fat content, which tends to be higher in processed meats, or maybe the iron in red meat causes excess oxidation and is the culprit?
The biologist in me returns to add: We inherently relish the taste of the things that aren’t good for us. Consider sugar and fat. Donuts. Ice cream. Throw in starch and you’ve got french fries, potato chips. Then add meat. Hamburgers. Pizza. Chicken wings.
Need I go on?
Why do we salivate over fast food gluttonies and not celery, carrots and cod? Because we’re still living with the urges that kept us alive over the past centuries when food was scarce and storing up calories was the best thing we could do for ourselves. If the Neanderthals had had a ready supply of cheese puffs, say at the corner store, they might have out-competed Homo sapiens and we’d be in a very different place today. Perhaps non-existent. Or maybe Homo neanderthals would have been less completive and we’d co-exist. They might let us have cheese puffs if we were very good co-inhabitants of their domain.
I’m side-tracked. Maybe because the topic of processed meat is too complex. Too tied up in what it is to be human. Just as it’s human to get caught up in a sensational announcement about the dangers of a food group we’ve been revelling in for decades.
We learn. We find better ways. We evolve, whatever that means to us.
¹ I made a trip to the WHO website so I could see the data for myself. First a few definitions. Red meat includes beef, pork, lamb and a few other things, like horse. Processed meat seems to be a broad category, including any of the above meats smoked, cured, salted, fermented or other. Already, I’m sceptical. Scientific studies tend to be very specific, not use broad groupings.
Next question, what specifically is the risk? Colorectal cancer, definitely, maybe stomach cancer too.
From the Q&A posted by WHO: “According to the most recent estimates by the Global Burden of Disease Project, an independent academic research organization, about 34 000 cancer deaths per year worldwide are attributable to diets high in processed meat.”
² Considering that there are 7.1 billion people on earth ( retrieved Nov 25, 2015 from here ) and in 2012 about 56 million people died (retrieved Nov 25, 2015 from here ), processed meats causing 34,000 deaths is a small fraction, at 34,000/57,000,000 or approximately 0.06% of annual global deaths. Of course, if you happen to be one of the people who develop cancer because of processed meats, it is significant to you and your loved ones.
Also from the Q&A posted by WHO: “These numbers contrast with about 1 million cancer deaths per year globally due to tobacco smoking, 600 000 per year due to alcohol consumption, and more than 200 000 per year due to air pollution.”
So, a person’s chance of dying because of eating processed meat is about 1/30th the risk of smoking.
It’s a bit unfair taking a global perspective on this when it really depends where you live what you are likely to die of (retrieved Nov 25, 2015 from here) . In developing countries, death is much more likely due to cardiovascular and infectious disease, especially in children.
In Canada, it’s estimated that 9,300 people will died of colorectal cancer this year (retrieved Nov 25, 2015 from here). That’s a sizable fraction of the global number of 34,000 (9,300/34,000 or 27%).
If we add the US, where slightly under 50,000 people are expected to die of colorectal cancer in 2015 (retrieved Nov 25, 2015 from here) , we can see that the processed meat number has been overtaken by total deaths from colorectal cancer. Certainly, it’s not the sole cause of such types of cancer. Worldwide, there were 694,000 deaths from bowel cancer in 2012 ( retrieved Nov 25, 2015 from here). So, 34,000/694,000 colorectal cancer deaths due to processed meats. Five percent.
But wait, there’s another dimension to this. How much consumption are we talking?
Q&A on WHO site says: “An analysis of data from 10 studies estimated that every 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by about 18%.”
Daily? I suppose if you ate a processed meat sandwich every day for lunch, you’d be testing these levels. But occasional consumption, not so much.
³ for example, the abstract to this paper: Cross, A. J. and Sinha, R. (2004), Meat-related mutagens/carcinogens in the etiology of colorectal cancer. Environ. Mol. Mutagen., 44: 44–55. doi: 10.1002/em.20030
4 Retrieved from http://www.cancer.gov/publications/dictionaries/cancer-terms?cdrid=658447 Nov 24, 2015