The Unintended Consequences Of Bicycle Helmets


–We should encourage people to cycle, not scare them away.

From personal experience I can attest that it is almost impossible, in the US at least, to have an intelligent conversation about bicycle helmets. The universal view is that you have to be crazy not to wear a helmet. Since I almost never wear a helmet this is not a good way to begin a productive conversation.

I think the issue is far more complex than most people believe. It’s a great example of unintended consequences, and that what seems obvious may not always be so.

Thrill seeking cyclists in Amsterdam defying death and injury.

Now let me be the first to admit that I am not against bike helmets. If you want to wear a helmet then you have every right to do so. I’m not going to argue with the proposition that if you fall on your head while cycling you are almost certainly better off if you are wearing a helmet. (But— and this is not my main point, just a point worth noting– it’s been suggested that wearing a helmet creates a comfort level that leads some people to take more risks. So it’s at least possible that for some people wearing a helmet may actually increase their risk.) Let me also acknowledge that you would have to be crazy not to wear a helmet in a bike race, or while mountain biking, or while taking part in any other sort of inherently dangerous type of cycling. My argument against helmets  only concerns routine commuter or casual recreational cycling.

Here’s my main point: I am opposed to public health campaigns that focus on helmets, thereby implanting in people’s minds the dangers of cycling. Instead, in my view, the public health agenda regarding cycling should be to promote the far greater health benefits of cycling. The overarching goal of any public health campaign should be to dramatically increase cycling in the US, thereby encouraging physical activity and helping to reduce obesity and diabetes.  In tiny Denmark, by way of example, one expert, Lars Bo Andersen, PhD, of Western Copenhagen University of Applied Sciences, reports that “26 persons were killed in the whole country in cycle accidents last year, but more than 6000 deaths were avoided due to the huge amount of physical activity this behavior is a result of.”

As I wrote last week, despite the increase in accidents linked to cycling, the overall public health benefits of cycling are enormous. If the goal is to begin to increase cycling in the US to levels seen in the Netherlands and Denmark, where cycling is a routine part of everyday life, then people will need to think about cycling the way they think about walking or taking the train. Cycling needs to be completely routine. Imagine if you thought you had to put to put on a helmet before walking or driving. You’d probably do it less often. (For a variety of reasons I won’t go into here I don’t think the seat belt analogy is relevant here.)

It is true that, given the less advanced infrastructure in the US and the absence of a cycling culture, cycling is more dangerous in the US than in countries like the Netherlands and Denmark. However, the public health benefits of cycling will likely be even greater in the US. Cycling in the US will never achieve optimal levels of popularity if helmets are viewed as necessary. Therefore, everyone should be encouraged to cycle; campaigns to increase the use of helmets in casual cycling are therefore counterproductive on the large scale of public health.

Western Australia perfectly illustrates the issue. Following enforcement of a law mandating bicycle helmets, cycling became less popular. Paradoxically, the roads became more dangerous for cyclists and motorists alike. The law had the overall effect of damaging the public health, the law’s critics contend.

I’m a baby boomer who grew up in the suburbs riding a bike. No one had a helmet in those days. Now I ride all over New York City on my hybrid bike and never wear a helmet. A major reason why I ride is to recapture a tiny bit of the feeling of joy and freedom that I experienced when I was younger. If I felt compelled to wear a helmet I suspect I would ride much less. In my opinion, despite the increased risk for a rare head injury, I am better off because of the decreased risk for all sorts of chronic diseases, not to mention the substantial and immediate increase in my overall happiness.

One argument in favor of helmets is that in Denmark, which rivals the Netherlands when it comes to cycling popularity, helmets are growing in popularity. But I don’t think this is a reason for a public health emphasis on helmets in the US. A public health emphasis on helmets in a nation that’s already achieved extremely high cycling levels may have a very different effect than a similar message in a nation with far lower levels of cycling. The first goal in the US should be to increase cycling. If this is successful and results in a big increase in head injuries then a helmet campaign might be warranted. For now, it seems to me, we should devote our messaging resources to getting people on bikes.


In response to arguments about helmets, Andersen makes an important distinction between promoting helmet use and legislation requiring its use. “I can support promotion but not legislation. The problem is you would get a fine every time you were caught without a helmet if you have legislation. In Denmark, the bike is used as daily transportation and sometimes it is not convenient to bring a helmet, because there is nowhere you can put it if you take your bike to the city. If you hang it on the bike it will be stolen and it is inconvenient to carry it around. This fact would decrease cycling substantially in Denmark if we got legislation. We know that 26 persons were killed in the whole country in cycle accidents last year, but more than 6000 deaths were avoided due to the huge amount of physical activity this behavior is a result of. Any reduction in cycling will cause more morbidity and mortality than all cycle accidents taken together. Therefore, helmet use should be promoted but not my legislation.”


  1. I couldn’t agree more (
    We need less helmets and more protected bike lanes!

  2. Stephen Sossin says

    I think they’re RIDICULOUS! Looking and functionality. My generation ( and every one before ) grew up riding our bikes ( which for 20 + years now- I almost never see school age kids doing- at break neck speed, EVERYWHERE! Never EVER heard of or saw anyone get hurt ( even those of us who took tumbles in our EARLIER childhood years ).. As an adult, in my 60’s.. I do not ( nor have I ever ) work ridiculous ‘spandex’ clothing that often is TOO TIGHT, nor a ridiculous ‘pointy’ in the front helmet.. WHICH by the way I have, in the past seen these are very dangerous as a frontal collision or fall cause that llloonnnggg point to really snap one’s neck backwards. Plus, I actually ride ‘leisurely’ actually SEEING the beauty of nature rather than the bulk of fools in their apandex and pointy helmets always ( it seems ) peddling like the wicked witch in The Wizard of Oz- flat out!!

  3. dearieme says

    (i) There was research in Britain some years ago that discovered that drivers take more risks with regard to cyclists if the cyclists are wearing helmets.

    (ii) Rather relevant to this blog: my GP insists that his patients on warfarin must wear helmets.

    (iii) I started wearing a helmet at my wife’s insistence when my daughter started cycling. Small children come off bikes quite often, and it would be hard to make the nipper wear a helmet if Daddy and Mummy didn’t wear them.

    (iv) Unexpected bonus from going to buy a helmet: I was told that all customers had either a French shape of head, or Italian. “Ooh” said the good lady, “yours is Italian.” I like to think that she meant “handsome boy”.

    • Larry Husten says

      As the picture at the bottom of the story shows, you probably shouldn’t visit Amsterdam. You will have a heart attack looking at all those small children w/out helmets!

      • dearieme says

        No, my wife would have a heart attack ….

        Especially since she used to cycle around with our youngest plonked in a Dutch basket.

  4. James Gaulte says

    The “Peltzman effect” needs to be mentioned . the gist is that safety regulations may have unintended consequences that sometimes counter the purpose of the regulation.

  5. Yep. Slow-moving commuter cyclists in areas with good biking infrastructure (like Copenhagen and other Euro-metropolises, *maybe* some stretches of downtown Manhattan and SF) probably have little to gain from wearing helmets, and there’s no way you’re gonna get bike share users to wear them. More people on bikes and more brakes on cowboy car culture (which contributes to the diseases of the sedentary lifestyle as well as pedestrian and cyclist deaths and injuries) are an all-around public good.

    The cyclists who *should* wear helmets are those spandex-clad idiots riding road bikes down 2nd Ave. in rush hour motor traffic at high speeds because they’re too cool for the bike lane, but y’know, good luck with that demographic…

  6. Good article that makes the key point… the health benefits of cycling far outweigh the potential risk of a crash. So I look at it as a two stage decision:
    1) Decide to ride
    2) Decide whether you want to wear a helmet while riding.
    Helmet use should never be a barrier to cycling. The clear harms of a sedentary lifestyle are too great.
    PS: I always wear a helmet now. But I was fully committed to cycling long before I started wearing a helmet… and to me it is no impediment.

    • Larry Husten says

      Great points, Andrew. You’ve helped me clarify my thinking. I have nothing against you or anyone else deciding to wear a helmet. Of course, I am not *against* people wearing helmets if they want to wear them. And as I said in the story I think they should wear them in non-casual cycling situations.

      The question then is about public health policy and how public health dollars should be spent. Helmets should *not* be the focus or even a target of public health campaigns, because, as I said, that strategy is counterproductive. You can save one head or life but at the cost of 100 or 1,000 cases of obesity/diabetes/CV disease.

      So let’s get people on bicycles. When Topeka starts to look like Copenhagen perhaps then we will want to change the focus of our public health campaign. But we have a LONG way to go before that happens.

  7. Magnus Dalen says

    Great article. I ride a mountain bike on streets & highways an average of 1,000 miles/month in sunny Florida. I began wearing a helmet 20 years ago when I discovered how much cooler I was with a helmet – the sun isn’t directly beating on your noggin & the air flows faster through your scalp via the vents that channel it past your head. Before the helmet, I hated cycling because it was so darn hot, but now easily ride 3 hours at a stretch. So, in my case, a helmet encourages me to ride, taking away a very effective excuse for sitting on the couch.

    Why does every rider in the Tour de France wear a helmet? I think it’s because it protects a rider from most head injuries that don’t involve a motor vehicle – that’s most accident situations. Hit some sand or a pothole, and you’re going down hard. Those Tour riders, like me and lots of recreational cyclists, clip into their pedals – most recreational riders or commuters don’t. Unlike the riders in Amsterdam, if you’re clipped in you rarely have time to get your foot down to the ground to prevent falling.

    A cyclist isn’t going to win in an accident with a bus, truck or 6,000 pound car, even if they wear the best race car crash helmet on the market. If that’s the kind of crash you expect to be in, stay home on the couch.

  8. Peter Hatfield says

    Epidemiological studies notably Olivier et al have not found robust evidence that MHL lead to decreased cycling exposure in Australia.. Cycling rates dipped after MHL – helmets were expensive at first – but returned to pre-MHL levls, presumably as people bought helmets. Now helmets are cheap and any drop in cycling numbers since then would be among very casual/occasional cyclists and so have little health dis-benifit (Hagel article in the BMJ.explores this).

    Australian research shows helmets liekly to have saved lives and prevented injuries. MHL led to a normalisation of helmet wearing but this is being undermined by the anti-MHL advocates who appear oblivious to the impact of their fashion statement on younger cyclists helmet wearing. .

Speak Your Mind