The team leader at the Laboratory for Proteolytic Neuroscience at Riken's Brain Science Institute is not a man usually given to making apocalyptic statements.

Yet when I asked him whether Japan should be investing more money in Alzheimer's research, he responded with more than the usual academic plea for more money. "Alzheimer's disease," said Takaomi Saido, "will destroy Japan's social-welfare mechanisms in the near future."

Saido, based in Wako, Saitama, is on a twin social and scientific mission: to protect Japanese society from the ravages of Alzheimer's disease, and to uncover the secrets of how the brain ages.