Is there any real correlation between handedness and average life span?

I’m sure we’ve all heard that old “statistic” that right-handed people live (on average) five (or so?) years longer than their left-handed counterparts.

• Can we really chalk it up to the dangers
of operating machinery in a right-handed world?

• Or shall we blame the increased prevalence of various
mental disorders linked with left-handedness? (ie LRRTM1)

• Or what about the theory that left-handed people live longer
because they are better utilizing the muscles around their heart?
(Or something like that.)

• While I’m tempted to call it a load of hooey, there are (seemingly valid) studies that correlate certain levels of intra-uterine testosterone to a predisposition for left-handedness as well as certain immune system disorders.

• Though if the former is true, would the creative side often associated with left-handedness be inherently masculine?
Or have I gone on a totally unsubstantianted tangent here (as usual)?

What thinks you?