My friend showed me the above documentary (propaganda piece?) and suggested that the vegan diet shizzle could nearly eliminate cancer in a population.
If the claims made are valid, it puzzles me that meat is as popular as it is.
So… are the conclusions from said documentary piffle-paffle or at least mildly credible?
Here’s a brief backgrounder on the claims:
Mods: This is a question about populations of humans, not individual medical issues, so I wasn’t sure if it went here or IMHO. Move as you see fit.
Meat is as poplar as it is because the claims are just silly.
The human body is NOT designed to be vegan. Our intestines are too short, we can’t process a lot of plant matter, and our bodies rely on proteins that are difficult to find outside of meat. Going on a strictly vegan diet without paying attention to what you are doing (particularly to proteins) can be very dangerous to your health.
In our modern society we are fortunate that foods that contain the necessary proteins and such and are also vegan friendly are readily available, so those who choose to live a vegan lifestyle are certainly free to do so. The idea that it is somehow better for you though is just hogwash. Your body isn’t designed for it.
Your body isn’t designed for a meat-only diet either. We are biologically omnivores, and no amount of wishing we were built differently will make it so.
The lesson here is not to eat processed junk food; in this case, meat that has anything other than just meat as an ingredient (e.g. that states “no additives/fillers”; I assume spices and other seasonings are OK though).
*Of course, “causes” should really be “contributes to risk of”
Note that this is a particularly extreme example of a diet based almost entirely on meat (one should ideally eat a balanced diet). Also, the prevalence of grain-fed meat (in addition to the overall diet) in today’s diet may contribute to disease; for example, most people eat far too much omega-6 fatty acids and not enough omega-3 (ratios of up to 30:1 or more), and the fatty acid profile of meat is similar to the feed (fish don’t make omega-3, they get it from algae, thus farmed fish may lack in it too).
Vegetarians have a lower overall cancer risk, but a sharply higher colorectal cancer risk over meat eaters.
(This is particularly pointed for me, as last year I lost a friend—a nonsmoking, nondrinking, cheerful, meditating, fit, active, 33-year-old Buddhist vegetarian—to colon cancer.)
Please note, as your link did, that that one study’s finding was “contrary to suggestions from other studies” which have found that red meat to be “associated with higher rates of colorectal cancer.”
One outlier study does not create a fact; it merely creates some small doubt about the previous conclusion.
As to the whole Campbell idiocy. We have discussed this previously. Beyond what was pointed out in the debunking link is the fact that Campbell intentionally misrepresents his own data and leaves out previous studies that he did that completely disprove his own hypothesis. (See link posts #51 and 52 in particular.) As I stated there:
Hmmm. He is scum, running a scam. His conclusion is dumb, and I do give a damn.
Seriously, I have a real problem with someone who presents themselves as a scientist, and then intentionally misrepresents his research to support the conclusion he prefers despite the fact that his research actually disproves his preferred conclusion. It gives the scientific process a black eye.
As your first cite notes Vitamin C greatly mitigates the risk of nitrates which is a good thing as many veggies have large amounts.
As with all epidemiological studies, even if there was a study that vegetarians had half the mortality as Daily meat eaters just dropping meat from your diet would to little to help.
People who tend to eat healthy also tend to make other choices based on health.
A stressful sedentary lifestyle has more impact on your chances of being one of the 25% who die of heart attacks than the source of your calories.
Cancer is not a specific disease. Saying that one thing or another “causes” cancer is similar to saying getting wet and cold “causes” upper respiratory infections. Other factors are usually involved and not as well understood as we would like them to be.
I believe the meat eating population is even higher than this. I recall seeing a survey from a couple years ago that put the vegetarian population at ~3% (defined as those who don’t eat meat, poultry or seafood - things like eggs and dairy were allowed).