Nutrition and the brain.

Severe nutritional deficiencies, such as protein energy malnutrition and deficiency of nicotinamide, vitamin B(12), folate, and thiamine, have long been recognized to cause severe confusion. Lesser vitamin deficiencies have been linked to the pathogenesis of delirium. Hypo- and hyperglycemia and hypertriglyceridemia can cause cognitive deficits. Epidemiologic and animal studies have linked several other nutrients (omega-3 fatty acids, lutein, alpha-lipoic acid, and the Mediterranean diet) to cognitive performance and the prevention of dementia.