I wrote this incomplete theory a while ago and thought it could be helpful.
What do you guys think?Start
You’ll have to read this.. http://en.wikipedia.org/wiki/Prostaglandin
And this… http://en.wikipedia.org/wiki/Neurotrophin
To understand this… http://www.ncbi.nlm.nih.gov/pubmed/15044028Vitamin K and the Nervous System: An Overview of its Actionshttp://advances.nutrition.org/content/3/2/204.long
The neuroscience seems to indicate that high intake of leafy greens mainly for Vitamin A/K and nuts/oily seeds for the non-oxidized Omega 6 fatty acids are required in high amounts with sufficient serotonin to produce enough series 2 prostaglandins, which are required to increase neurotrophin levels, which eventually increase the number of neurons.
I haven't seen any research which indicates that Omega 3 fatty acids increase neurotrophin levels.
Prostaglandins are required to remodel the skull and the series 2 prostaglandins are more effective at bone resorption/remoldelling than the series 3 prostaglandins.
Vitamin D3 inhibits the production of series 2 prostaglandins. Those living further away from the equator have bigger skulls because they have lower levels of Vitamin D3 compared to those living closer to the equator. Less Vitamin D, less inhibition on neurogenesis however skull bone will not form without sufficient Vitamin D.
I don’t doubt we ate animals for survival purposes but animal fat is very low in Omega 6 fatty acids unless animals are force fed nuts and seeds high in omega 6 fatty acids. Plus if meat increased cranial size; big cats wouldn't have small 350cc cranials.End