When does middle age (and old age) begin?

http://www.medicaldaily.com/section/news/us-world.htm

Hi Folks,

Please check out the "Middle Age May Actually Begin at 55" entry on the link.  I tend to agree with the folks researching the 1,000 participants in the UK who've concluded that middle age begins later than we had assumed, and ends at age 69 and 277 days.  What that means, of course, is that we have to ratchet up the bar for those of us post-middle age; something I've been saying for a while. 

In any event, the same predictors hold true for both middle and (dare I say it?) old age.  Which is ... that both middle and old age is a state of mind, rather than something that begins at a certain age.

What do you say?

Regina