“The researchers ducked the obvious question of whether it might be simpler, faster and cheaper to simply light up a joint. “Could people smoke marijuana to prevent Alzheimer’s disease if the disease is in their family?” Wenk said in a statement. “We’re not saying that, but it might actually work.””

http://www.scientificamerican.com/blog/post.cfm?id=pot-joins-the-fight-against-alzheim-2008-11-19