Nature is reporting that researchers have identified the protein, named amyloid beta, which causes plaque to form in the brain. It has long been known that Alzheimer's patients have buildups of plaque in their brain, but the link between protein and plaque was not clear. New research indicates that mice who have low levels of this protein do not exhibit dimentia in later years.

 

Study Information: Ohno, M. et al. BACE1 deficiency rescues memory deficits and cholinergic dysfunction in a mouse model of Alzheimer's disease. Neuron, 41, 27 - 3, (2004).

I saw that somewhere a long time ago in the New Scientist, I think. It is a good sign, though.

Drinking 3 glasses of alcohol per day will reduce the risk of alzheimers and dementia by 50%... and no, drinking more does not increase the benefits.