Do helmets keep you safer in an accident? Or by discouraging cycling, do they increase your risks in other ways?

I'd like to think they keep us safer.

But this made me rethink that.

Anyone who has landed on their head in a bike accident (flipping over your bike, which is rather common) know bike helmets make you safer.

Landing and sliding your bare head at 15-20mph across a surface like concrete or asphalt is not only unpleasant, but leaves most with some rather nasty wounds.

I have not flipped my bike, and do not think it is common for bike commuters -- as opposed to mountain bikers who really do it all the time. However I have landed on my face while going at a good clip, and it was unpleasant but the helmet neither hurt nor helped.

If helmets discourage you from bike commuting, they are exchanging the rare situation in which a helmet saves you from a direct head impact, for the near certainty of fitness-deficiency related illnesses in our society.