Big news here in the UK this morning is a supposed link between processed meat and pancreatic cancer...although the news report I heard mentioned that this link was additional to the already identified links with obesity and smoking.
Is anyone going to change their approach to bacon as a result of this finding?
This is a perfect example of media hype. The article never mentions any scientific information and also doesn't give any detail about how these percentage increases in risk are arrived at. If there's one thing they evidently don't teach in J-school, it's this:
CORRELATION DOES NOT EQUAL CAUSATION
Remember the story last week about the correlation between a 'fatty diet' and brain damage? It was discussed at length here and on Marks' Daily Apple. http://www.marksdailyapple.com/does-high-fat-diet-cause-brain-damage/#axzz1jKZiiHC5. Exactly the same kind of thing. OMG! Stop eating fat! You're gonna get brain damage!
Bottom line for me: don't base your diet on what you read in newspapers. You'll be freaking out on a daily basis and that's not good for cortisol levels.
Why would you want to cut down on bacon? If you're afraid of nitrates, buy the uncured kind. If you're afraid of CAFO meat, buy pastured.
This story periodically crops up in the media. Dr David Colqhoun has written a pretty definitive piece on this whole topic. It really is a great article, highly informative on how statistics are manipulated by the popular press. In fact it gives a great primer on the broader issue of statistical analysis in research. A very powerful and informative must-read post.
"In the UK there were around 5 cases of colorectal cancer per 10,000 population in 2005, so a 20% increase, even if it were real, and genuinely causative. would result in 6 rather than 5 cases per 10,000 people, annually. That makes the risk sound trivial for any individual. On the other hand there were 36,766 cases of colorectal cancer in the UK in 2005. A 20% increase would mean, if the association were causal, about 7000 extra cases as a result of eating processed meat, but no extra cases if the association were not causal. "
If i eat whole grains, i have 100 percent chance of becoming a type two diabetic. thats my history. If i eat bacon, i have a slim chance of getting pancreatic cancer. why is it i dont read in the paper to avoid grains? All i read is eat whole grains to delay becoming diabetic for 5 years.
When they define "Processed meats" so broadly as to encompass everything from cheap cereal-and-soy-filled sausages to organic bacon I'm left wondering just what validity these studies are supposed to have.
Little late to the party here, but maybe someone will scroll this far down and read this...
There are tons of problems with epidemiological studies like this one, and they've been discussed everywhere, including paleohacks. So I'm not going to spend too much time rehashing it, but I want to point out a couple of things:
1 - do you know what they classify as "processed meats"? If you're a researcher doing this study, you have to take everything a person eats and break it up into the predefined categories you want to study. Do you break it up by mass, volume, calories? Well, there's a study from the UK that says processed meats cause cancer (maybe it's the one you linked too or another one, I don't know I didn't read this one) and they took ALL of the calories from a slice of pizza and said that it's a "processed meat" if it has pepperoni on it. So unless you read the actual paper and talked to the researchers you don't even know how the foods are classified.
2 - When you do an epidemiological study, you're going "hunting" for correlations. And that's not science. You can hunt for correlations to start your study, to help direct the research, but you should NEVER use them for actual results. Here's why: when you look for a correlation between two variables, you have to pick some level of "confidence" that the correlation is actually a correlation and not just there "by chance". The standard in science is usually p=0.05 (or p=0.95 depending on whether you're coming from mathematics or statistics). What that means is that there's a probability of 5% that your correlation is "by chance" and not actually there. That sounds pretty good, but 5% is 1 in 20. So when you have a huge table of numbers from n epidemiological study and you take every pair of columns and look for a correlation you can easily run across some that are there "by chance". And since the non-correlations aren't reported, you don't know how much they tried to find something that is "significant" and it could be by chance. Here's my favorite cartoon that show this phenomenon: http://xkcd.com/882/
Just like we should always say "correlation does not equal causation" we also need to say "epidemiological studies are only good at best to generate a hypothesis"
I don't pay attention to the media either. They brainwash people that whole grains are good for you and help you lose weight, blah blah blah. They also promote genetically modified foods and corn syrup and everything else unnatural.
I try to stay away from nitrates, but this article is interesting to read, so I wonder if the whole labeling of foods as Nitrate-free is one of the marketing hypes too
One major problem with these studies is how can you possibly separate it out from every other factor in someone's life? On top of that, they never take quality into consideration.
I've been trying more and more to source all my bacon and processed meats (sausages, ham) locally. I have a pork belly in my freezer, and I'd like to attempt making my own bacon, though I hear it can be a little tricky to nail down a good method.
So no. Bacon will continue to be on my plate occasionally. Had it this morning scrambled up with eggs, sweet potato, onion, and mushrooms. Yum.
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