This thread has showed me that there is at least some anecdotal evidence that more, cooler air may help, so thanks for that. I'm also in agreement that a hot, stuffy cabin is no fun in turbulence.
I'm still of the opinion though that if we're starting with a comfortable cabin environment, lowering the temperature will just cause a cold, bumpy ride.
@parabellum, newer A320's allow the cabin crew to control the temperature in the manner you've described.