Lack of folic acid dementia link
Extract from the article on the BBC website:
"Dementia is three times more common in people whose blood is low in folates, a form of vitamin B particularly found in green vegetables, a study suggests.
The Journal of Neurology, Neurosurgery and Psychiatry study followed 518 South Korean pensioners for two years.
There is growing evidence linking levels of folates - or folic acid - and Alzheimer's disease, though deficiency could be a symptom of dementia."