From back in 2009, a pretty interesting article about the connection between flexibility and arteriosclerosis: Health and fitness: Stretching is good for your arteries - latimes.com;
From the study abstract:
"Flexibility is one of the components of physical fitness as well as cardiorespiratory fitness and muscular strength and endurance. Flexibility has long been considered a major component in the preventive treatment of musculotendinous strains. The present study investigated a new aspect of flexibility. Using a cross-sectional study design, we tested the hypothesis that a less flexible body would have arterial stiffening. These findings suggest that flexibility may be a predictor of arterial stiffening, independent of other components of fitness."
Here's the link for the study: http://ajpheart.physiology.org/cgi/content/full/297/4/H1314.
So, with a grain of salt, because of the words "independent of other components of fitness," this seems like yet another good reason to stretch!