The biology department of MIT is currently researching a gene in the mouse brain, known as SIRT1. This gene has been shown to govern a class of proteins known as situin one, which are involved in cellular regulation of things such as longevity and a cells ability to respond to stress. So far the results indicate that mice with a model of Alzheimer's disease that were genetically engineered to produce more sirtuin one, maintained cognitive abilities as they aged, has less inflammation and fewer plaques in their brain. Mice without this extra sirtuin one, and those who were engineered not to produce any sirtuin at all, showed the steep declines in learning ability and memory as they aged, that is often associated with Alzheimer's. The later group, the SIRT1 knockout mice, showed the greatest declines.
Interestingly, resveratrol may somehow help to increase the expression level of SIRT1, as does caloric- restriction, a diet which has been shown to increase the longevity in just about every living thing. It is for this reason that SIRT1 is often referred to as a longevity gene.
Although previous petri-dish studies have suggested a link between SIRT1 and Alzheimer's, the study at MIT more definitively indicates such a link. SIRT1's specific involvement in the disease comes from the genes ability to cleave amyloid precursor proteins into smaller, harmless, protein fragments.
While these findings certainly provide a degree of hope, the biggest obstacle in creating a drug that increases SIRT1 in humans, will be in finding something that can effectively cross the blood-brain- barrier.