Creatine supplementation improves brain performance in vegetarians [pdf] - http://www.ncbi.nlm.nih.gov/pmc...
This research is from Sydney, where I am, and also it's a very strong result. One study only, but IMO well-designed and with results that (a) are in areas likely to matter in daily life, and (b) are of a magnitude that people would notice on a daily basis. Brain energy and brain performance are related. Very interesting. - Daniel Dulitz