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Does cycling cut cancer and heart disease risk?

Or are people who are at relatively low risk of those diseases more likely to cycle?

Or both?

The way the headline reads, many people will be led to believe "Oh, if I start cycling, then I'll cut my risk of cancer and heart disease."

This study does not lead to that conclusion. All we can say is that there is a correlation between cycle and lower cancer/heart disease risk - even when accounting for a few other factors.

Given that there are other ways of concluding that regular aerobic exercise cuts cancer and heart disease risk - and indeed the preponderance of the evidence suggest that it does.

But I doubt the effect is really to almost halve the risk of those diseases.




I've no source to cite, but AFAIK similar observations have been made in multiple studies in countries where cycling has been/is becoming quite popular (e.g. Netherlands, Denmark, Sweden) and as far as I remember, they did control for many external factors in at least the Danish study I recall.

I know, vague hand-waving, but hopefully others can pitch in with data.


I was a bout to say: as a Dutchman I'd like to see some comparisons between our population and the neighbouring countries.


well, for a start.. Dutch men are among the tallest in the world[1].. and taller people have different health risks[2] (higher cancer, lower heart disease). So.. I dunno but I like cycling to work anyway :)

[1] http://www.bbc.com/news/science-environment-36888541 [2] http://blogs.discovermagazine.com/crux/2013/11/08/is-being-t...


From the article:

> The way the study, published in the British Medical Journal, was carried out means it is not possible to determine a clear cause and effect.

> However, the effect was still there even after adjusting the statistics to remove the effects of other potential explanations like smoking, diet or how heavy people are.

> It means the reason cycling cuts cancer risk cannot be down to weight loss in the study.


The increased probability of being killed by a motorist reduces your net probability of dying from anything else regardless.

Joking! (Well, mostly.)


I bike on city streets. So not only is there the risk of impact, but I'm also breathing all kinds of exhaust. That can't be good...


realistically, everybody else is also breathing the same air though?


Don't most cabin air filters take out the big particles in diesel exhaust? I think Tesla does at least.


I think there are some studies from here in the UK which indicate that air quality may actually be worse inside motor vehicle cabins than it is outside [1].

This may be mitigated in newer vehicles with particulate filters, I am not sure. I don't know whether filters can eliminate NOX as well as PM2.5.

[1] http://www.bbc.co.uk/news/health-35504768


Plus, when I'm on my bicycle I'm breathing much harder than most people in cars and I'm in it for longer because I'm slower.


The article mentions that by the metric of all causes of death, the bikers still have a 40% lower death rate.

There have been a number of other studies that put the expected increased lifespan (due to better health) vs expected decreased lifespan (due to accident) anywhere from 7:1 to 70:1. And that is just mortality; biking brings a host of benefits on top of that.


I believe the death rate for all human beings is 100%, so if they can reduce it to 60% that's a miracle.

I was making a joke (and I am a cyclist), but appreciate your reply.


Cycling more than likely increases the likelihood that you get creamed by a vehicle that didn't see you. But hey, no cancer :D


It's not the vehicle that doesn't see you, it's the driver. If we make it acceptable for them to hit cyclists (like we tend to), they'll keep "not seeing them".


I agree.

I recall another study that linked regular flossing with reduced heart disease. However, that study was on a behavior that was much too narrow -- People included to floss are also much more likely to engage in other health-positive activities.


That's what drives me crazy about 'findings' like these that we're being presented with, every day.

For example when comparing mortality rates of drinkers and non-drinkers, the fact that a lot of non-drinkers are former alcoholics with significant health issues is often ignored.


Do you have some examples of studies that don't control for previous behavior?

Asking about it just seems like such a basic component of the data gathering.


You'd think but apparently not always the case. See this https://www.bloomberg.com/news/articles/2016-03-21/health-dr...


It seems many studies even gather the data and then ignore it (by choosing to lump together former drinkers and life long teetotalers).


Having published research is a required part of the cv for many jobs. There are a lot of researchers out there who view it as a necessary evil. They'd be unlikely to put their heart and soul into it. And that's before you even get to researchers who might have motivations to achieve certain outcomes. Say ones who receive funding from certain industries.


heart I can understand but cancer it seems improbable.


There is some evidence that cancer is linked with obesity: https://www.cancer.gov/about-cancer/causes-prevention/risk/o...

It makes sense that obese people are less likely to bike to work, and also that people who bike to work are less likely to become obese.


I still disagree in essence. I know that obesity increases risks but I don't remember how much, it seems a complicated situation with a small effect, compared to say... smoking.


General fitness is cancer-preventative; this is just a specific study with some nice numbers showing that.




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