> If this is a significant treatment of Alzheimer's then that's a breakthrough to me, what bar would you set?

Wouldn't having some kind of proof against a placebo or at least a dose-dependent improvement be the least possible requirements to actually believe the paper found any kind of effect at all?

If you randomly give 6 Alzheimer's patients an apple a day for 5 weeks, they could show improvements in cognitive tests by pure accident, especially for a disease that is known to ebb and flow.