I think this is a recent development and it is mostly older people who would previously not cycle as much anymore, but now drive e-bikes and so are going a lot faster while being physically more fragile. I think they were mostly one sided incidents (them driving into stuff or slipping).

For those people, I’d indeed recommend or mandate a helmet.

Do consider that in the Netherlands, people cycle 15,000,000,000 kilometers per year (that’s over 800 km per year per citizen, including babies etc.) to put the 50,000 injuries into perspective.

(Dutch source: https://www.fietsersbond.nl/ons-werk/mobiliteit/fietsen-cijf...)

I have a theory that requiring helmets would reduce bicycle usage, making people in general less healthy. It would also increase the ratio of cars to bikes, making roads more dangerous. I think the net effect would be worse outcomes.

I'd love to see evidence of this (either proving or disproving) but it seems like a hard thing to measure.

That said, I always wear a helmet when biking, but I never wear a helmet when driving, and I am aware of the irony.

A Dutch satire program had an item on this (https://www.youtube.com/watch?v=WflYjsaC19g). A lot of these injuries is with the elderly and the teenagers. It is suggested that this due to the rise of e bikes, which go faster.

A helmet should be required for ebikes.