Originally Posted by
I-Like-To-Bike
The unanswered question arises then what is so special about bike commuting and by what mechanism it allegedly reduces the risks of diseases such as cancer and does it apply to all other types of "active" bicycling?
You are 100% on the right track. Identifying the correlation between bike commuting and staying alive is interesting, but without the why, mostly useless. Someone pointed out earlier in the thread that correlation does not necessarily imply causation. These results we are looking at, as an example, might be explained by something different in the air you breathe on each type of commute. My point is that we just don't know. More research is needed.