Good news for Alzheimer's disease patients. A recently published randomized, double-blind, placebo-controlled, multicenter trial indicates butyrate derivatives improve cognitive functions.... COMMENTS from the Longevity Institute: Butyric acid is a short chain fatty acid present only in butter and absent in vegetable oil -  The suppression of butter and its replacement by vegetable oil  may well have been a factor in the spread of Alzheimer's disease.