I was interested to see the effects of a vegetarian/vegan diet on cognition, and as well as finding interesting data showing the importance of supplementing your iron and B12 levels when taking on a low cheese/egg vegetarian diet, to keep your cognitive levels high, I also found some other interesting studies.
One of the most interesting took a look at this question from the other side of the fence, did having a high IQ mean you’re more likely to be vegetarian? The answer seemed to be yes!
Admittedly this data is super old, and not worldwide in its consideration ( it’s a 1970s British cohort study) but interesting all the same as I had never considered this before: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1790759/
Looks like vegetarianism is the smart choice 🙂