Here are two credible reviews / meta-analyses stating the contrary, that is, that bicycle helmet use or legislation does, statistically, reduce head injuries.
That said, despite personally wearing a helmet on my daily commute, I don't support legislation. I unfortunately don't have sources on hand, but I firmly believe that spending public dollars on bike infrastructure and better legislation for bicycle/car interaction would yield better safety improvements for cyclists AND increase cycling uptake.
I always wore a helmet when I cycle commuted, so I think I mostly agree, but I will point out that my major objection to legislation is on the grounds that it would deter cycling, and therefore be a net negative for health overall, and that one of the most important factors for cycle safety is the number of cyclists, so anything that puts people off cycling creates a negative re-inforcement that makes everyone still cycling less safe, and every new cyclist makes everyone safer.
At least one of your studies notes that it doesn't cover that argument:
> None of the included studies measured actual bicycle use so it was not possible to evaluate the claim that fewer individuals were cycling due to the implementation of the helmet laws. Although the results of the review support bicycle helmet legislation for reducing head injuries, the evidence is currently insufficient to either support or negate the claims of bicycle helmet opponents that helmet laws may discourage cycling.
Use or legislation of helmets while driving a car and walking would also almost certainly reduce head injuries. It's far from a sufficient argument for legislation.
Head injuries in car accidents are very uncommon, and the same with pedestrians. Pedestrians aren't likely to hit their heads on concrete at speeds well beyond that which the human body was designed for. Car accident victims don't have hard surfaces to hit their heads on in cars, and instead get other injuries. That's why seat belts are required by law in most jurisdictions, and also why airbags are mandated in all new vehicles.
Are you trying to argue against seat belts and airbags now? Are you going to claim that you're safer being thrown clear?
The studies discuss the rate of accidents, not the sum difference, meaning that even if there were more or less bicyclists on the road, the probability of them being injured with a helmet on is still less.
http://www.sciencedirect.com/science/article/pii/S0001457500... http://www.cochrane.org/CD005401/INJ_bicycle-helmet-legislat...
That said, despite personally wearing a helmet on my daily commute, I don't support legislation. I unfortunately don't have sources on hand, but I firmly believe that spending public dollars on bike infrastructure and better legislation for bicycle/car interaction would yield better safety improvements for cyclists AND increase cycling uptake.