Don't forget that it is not easy to remove confounding with smoking, drinking, low physical activity etc. as, incidentally, those who eat most meat happen to also score worse with those factors. Of course, there are statistical methods, but there are reasons to believe that not all confounding may be properly removed.
For those interested in statistics behind studies like this, I think this (not very long) video is a good explanation why it is not so easy to remove all residual confounding:
The lector actually discusses a very similar or even the same study - mortality as a function of meat consumption. Not too complicated for a technical person even without a background in statistics, I believe.
> Don't forget that it is not easy to remove confounding with smoking, drinking, low physical activity etc. as, incidentally, those who eat most meat happen to also score worse with those factors.
And those who aim to be healthy will probably try to be at least moderate w.r.t their meat intake because they have heard that meat is unhealthy, which further "proves" that meat is unhealthy, while in reality it might be because of other habits that they might have, like exercising.
Things like paleo might make things a little less one-sided.
For those interested in statistics behind studies like this, I think this (not very long) video is a good explanation why it is not so easy to remove all residual confounding:
https://www.youtube.com/watch?v=3hnWaNThBFw
The lector actually discusses a very similar or even the same study - mortality as a function of meat consumption. Not too complicated for a technical person even without a background in statistics, I believe.