FTA: "The researchers noted that previous experiments with flies found that bacterial infection threw off the insects' circadian rhythm, and not having this internal clock working properly made them highly susceptible to infection."

I wonder how much of an effect caffeine has on our circadian rhythm and how much that might be screwing with our health. I've looked around a little and haven't been able to find any studies on the two.

It would be funny if caffeine actually makes people healthier by making the circadian rhythm more pronounced (for those who consume caffeine at the same time each day).