Correlation does not prove causation. Also, there might be downsides to avoiding meat: in general, carnivores tend to be smarter than grazing animals, so it is possible that the non-dying vegetarians are also dumber. I haven't eaten meat in 8 years, maybe I am getting dumber and dumber. :)
Correlation does not imply causation, correct. I only eat meat one day a week; notably, days that start with "M".