[extropy-chat] Kurzweil and aging

[TC]

I've been working my way through The Singularity is Near, and ran into what
struck me as a pretty bizarre claim.  An excerpt from p. 211:

"When I was forty, my biological age was around thirty-eight. Although I am
now fifty-six, a comprehensive test of my biological aging (measuring
various sensory sensitivities, lung capacity, reaction times, memory, and
related tests) conducted at Grossman's longevity clinic measured my
biological age at forty. Although there is not yet a consensus on how to
measure biological age, my scores on these tests matched population norms
for this age. So, according to this set of tests, I have not aged very much
in the last sixteen years, which is confirmed by the many blood tests I
take, as well as the way I feel."

What?  Taking that at face value would imply he'd live to a good 350 or so,
and I have a hard time believing that's what he's saying here.  And if not,
what relevance at all does that "biological age" hold?  Anyone have a
clarification?

-tc