That's an interesting question. I guess the premise being that if your upper body blood vessels are made to be more flexible and wider that blood flow would increase to the upper body during cycling as the heart rate increases, thereby taking away more blood from the legs.

That would be an interesting research study. My thoughts are, even if there is a slight decrease in my cycling performance and I do think it would be very slight, if at all, then I'm willing to take that as a trade off for having overall lower blood pressure in general -- after all, no one pays me to cycle.

I'm sure professional cyclists would have a different opinion.