Arthur, the research on acupuncture is quite clear regarding pain relief, which is why it is being used in hospitals and other conventional settings where chronic pain is a sustaining and expensive problem. Research on other conditions, like alzheimers, so far as I can tell, is as you suggest slim to none. But that really means "un-researched" rather than research=fail. NIH/NCCAM is funding new studies to look at the underlying biologic/nervous systems that appear to be in play.
NCCAM has funded research into acupuncture for many years, in particular through the work of the University of Maryland Medical School's Center for Integrative Medicine. This clinical and research center works within the evidence base, and in fact helps establish it. This page has some info on its acupuncture focus, part of broader integrative and medical practices (they have not looked at alzheimers that I know of).
http://www.compmed.umm.edu/integrative/serviced_desc_acupuncture.asp
Otherwise, a friend of mine who was CEO of a major US medical system took some docs to China to consult with US firms interested in setting up conventional western care centers. While there they witnessed a C-section, in which the mother had no anesthesia, but was treated with acupuncture. Something is at work. let's find out what.
As for that site you refer to, I see that the writers are all MDs. I'm sorry, but sometimes MDs are not the most qualified at making connections in medical science, parsing the literature, or understanding the broader issues.