Will Cycling to Work Really Cut your Risk of Cancer and Heart Disease by Half?

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I am a cyclist.

It is by far my preferred mode of transport.

I cycle around town, I cycle to the shops, I go on bike rides for fun.

You’d might think therefore, that I’d be joyfully and uncritically tweeting and sharing around the recent press coverage of the latest study on cycling and health, such as the following in the metro:

Cycling to work ‘cuts risk of heart disease and cancer by half’

No words minced there by bastion of accurate and informed investigative reporting that is the metro…

Tempting as though that might be however, I am not going to celebrate this “good news”, as that would be very intellectually dishonest of me.

VolkerSchnaebele / Pixabay

Correlation Still Doesn’t Mean Causation, Even When You’d Really Like it to…

I’ve talked many times on this blog about the limitations of observational studies.

They are interesting, and they are useful, but they simply can’t be used to draw conclusions about cause and effect.

Just as the numerous inflammatory news reports based on observational studies that claim that red meat consumption increases risk for cancer and heart disease should be viewed with a skeptical eye, so must this study claiming that cycling to work will reduce them (Or maybe you can keep a balance by cycling to work while eating a bacon butty…).

This article is a great example of the uncritical, and irresponsible reporting of observational studies I talked about in a recent article on Jazz Musicians.

The Metro committed the ultimate sin, by presenting the associations between cycling to work and reduced risks of death from cancer, heart disease and all causes as causative:

Cycling to work cuts risk of heart disease and cancer by half

Fancy cutting the risk of developing heart disease and cancer by almost half? Then cycle to work

Cycling will cut the risk, according to new research

Not a may, might or maybe in sight.

Irresponsible journalism indeed, and not only from the metro I might add. Searching “Cycling to Work Heart Disease Risk” brings up a full-page of results, with only one, The Independent, adding the qualifier “Could” to their headline.

There are lies, damned lies and statistics. Mark Twain stevepb / Pixabay

The Independent go a step further towards good reporting in their article by including the following quote (emphasis added):

The scientists said: “The findings, if causal, suggest population health may be improved by policies that increase active commuting, particularly cycling.”

To be fair to the press on this occasion however, the scientists themselves are certainly not shy in implying a probable causative link, and suggesting that encouraging people to cycle to work could have public health benefits in the study itself (No doubt shills of Big Cycling):

This has important policy implications, suggesting that policies designed to affect a population level modal shift to more active modes of commuting, particularly cycle commuting (eg, cycle lanes, city bike hire, subsidised cycle purchase schemes, and increasing provision for cycles on public transport), present major opportunities for the improvement of public health.

Association between active commuting and incident cardiovascular disease, cancer, and mortality: prospective cohort study

Cyclists are like Jazz Musicians

As with all observational studies, the authors claim to have done their statistical shenanigans, ensuring that other factors such as “sex, age, deprivation index, and ethnicity, smoking status, body mass index, leisure time, occupational and DIY physical activity, sedentary behaviour, and dietary intake” were adjusted for.

Just as with Jazz Musicians however, we cyclists are peculiar beings. Yes, there are many differences between us – lycra or casual wear, helmet or basket with flowers etc, brompton or fixie, but there are no doubt also a great deal of similarities. Many complex, intertwined, and unadjustable differences which can’t be magicked away with the wave of a statistical wand.

My skeptical title for the results of the study would be:

The type of people who choose to cycle to work, have lower risk of heart disease, cancer and all cause mortality

It is this element of making an active choice, which I think most likely is what leads to the difference in findings between walking and cycling to work.

Walking is widely considered to be one of the best things one can do for one’s health – why have the researchers not seen the same benefits as with cycling?

They hypothesise that it’s something to do with intensity or duration. Personally, I’d guess that it’s more to do with the motivations, mentality and personality types of people who walk to work, rather than those that choose to cycle.

I.e. the vast majority of people who walk to work, do so because they work close to home, and taking public transport or driving, would just be totally impractical.

The majority of those that cycle to work though, do so because they have made a determined choice.

Cyclists are a different breed gdakaska / Pixabay

Yes, there may be some who do so out of necessity – they can’t afford a car, public transport is too expensive, unreliable or doesn’t do the route, and so on, but this is not the case in the majority of cycle commuters that I know.

I choose to cycle myself, and though I love it for many reasons (of which I shall elaborate in a minute), it has to be acknowledged that there can be down sides – inclement weather, sweating, punctures, having to take a change of clothes, bike thieves and dangerous roads to name but a few.

If we were to take Sid the Cyclist’s bike away from him, and make him take the bus, give it to Dave the Driver, and force him to cycle against his will, would we see a dramatic reversal in their longevity prospects?

I very much doubt it. Perhaps even the opposite!

Avoiding Heart Attacks vs Avoiding Lorries

Reducing your risk of heart attack by half sounds pretty impressive, who wouldn’t want to do that!

How about this for a statistic then:

A cyclist travelling a mile in Great Britain is 15 times more likely to have a fatal accident than a car driver going the same distance. Statician Jamie Jenkins for www.bbc.com

He’s not the only one at risk on the road! klimkin / Pixabay

Blinkin’ ‘eck, expressed as a percentage that a 1500% increased risk!

He does go on to qualify I should add, that the overall risk of death from either is low.

In 2013, in Britain, there was 1 cycling death for every 29,000,000 miles cycled. You’d need to be doing a pretty serious daily commute to rack up that kind of mileage before retirement…

If all things were equal, a 50% reduction in your risk of death from heart disease or cancer, two of the biggest killers, could potentially more than compensate a 1500% increase in your risk of death in a traffic accident.

But all things aren’t equal.

  1. Cycling to Work MAY Reduce your Risk of Heart Disease and Cancer, but it DEFINITELY Increases your Risk of Road Death.
  2. If the aforementioned Sid and Dave were to keep all things in their lives equal, save for their mode of transport to work, it’s very unlikely they’d have any significant impact on their risks of heart disease or cancer. There are too many other significant factors such as genetics, diet, wealth, education, smoking, alcohol, attitude, overall activity, sleep etc which play a role.

    All of these same factors (along with many others), which we will look at shortly, also affect your risk of being involved in, or surviving or not, a road accident, but nowhere near to the extent of whether you’re in a car or on a bike at the time.

  3. We all still have a 100% Risk of Death
  4. Statistics, especially relative risks, can be pretty mind-boggling.

    One thing, that can be said with a fair amount of certainty, however, is that we all have a 100% risk of dying.

    Well, who knows, maybe if we’re lucky, we’ll live to see the singularity, it will result in benevolent super intelligent AI, and we’ll all be made immortal, either in physical or digital form uploaded to the cloud. But best not to pin all your hopes on this scenario.

    What we are really concerned with, is maximising our time on this planet – even more importantly, in my opinion, is maximising our quality time on this planet. Indeed, that is really the primary focus of this blog.

    With a bit of luck, and the right genetics, you should be able to get 80+ good active, productive, enjoyable years of life.

    Heart disease, cancer and road deaths, are all considered as “avoidable deaths”. Succumb to any one of them, and you are going to lose some of those 80+ years of quality life.

    Around 70,000 people in the UK die every year from coronary heart disease, whereas in 2014 cycling road deaths were just 113.

    A lot more lives lost to CHD. But what about years of quality life?

    Around 65% of CHD deaths are in the over 75s, a loss of around 5 years of life, the next 17% in the over 65s, around 15 years. 8% of CHD deaths are in the over 55s. That’s 25+ years of potential life lost, pretty crazy.

    Cycle deaths can occur at any age however. If you’re 20 and get hit by an HGV, that’s 60+ years lost!

    I don’t want to belittle the tragedy of dying at 75 from a heart attack. It is indeed tragic, and you should do what you can to avoid it. It can’t be compared to being struck down in your prime of life however.

    Years of quality life, isn’t just about life or death either.

    A cycling accident doesn’t necessarily result in either just a few scratches, or death, there’s a spectrum in between.

    Around 3500 cyclists are seriously injured every year. Brain damage, paralysis, loss of limbs, the human body does not come off well in high-speed collisions involving concrete roads and tons of metal, even if you’re a gluten-free raw paleo vegan keto crossfitter!

    My aim is not to put you off cycling. On the contrary, I’m going to try to persuade you in a moment, I just want to make sure you’re doing it for the right reasons (and safely).

    How about cycling while eating fast food? JuralMin / Pixabay

    [Tweet “Cycling is great, but don’t cycle to work in the hope of gaining extra quality years of life”]

    There’s still no hard evidence that it’s really going to make a difference in the grand scheme of things, and if it does, it’s probably going to be the difference between dying at 80 instead of 78.

    The chance of 2 years of extra life is nothing to be sniffed at, but is it worth gambling 40 the or more years you might lose via a traffic accident, no matter how small that risk is?

    I would say, no, probably not.

    Don’t put your bike on ebay just yet!

    Sorry for all the horrible, depressing, potentially off-putting statistics there.

    Let me stress, in the grand scheme of things, cycling isn’t actually that dangerous.

    Pedestrians actually have a higher risk of being killed in a traffic accident than cyclists (though cyclists have a far greater risk of serious injury).

    It should also be noted, that by far the majority of cycling deaths are on country roads. That is to say, most likely these are not cycle commuters, but leisure cyclists out for bike rides for fun.

    Bad news for those who like to get out on the country roads at the weekend, but good news for those commuting to work.

    It should also be fairly obvious, that the riskiness of a cycle commute varies massively depending upon the route, the time of day, and the rider.

    Some cycling safety tips/common sense:

    1. Wear Safety Gear and Use Lights
    2. Yes, there is a bit of a debate about cycle helmets.

      Personally, I choose to wear one. There is little question that they do protect you in the case of an accident. Some argue that they increase your risk of being in an accident – cars give less room, and riders themselves take more risks. While you can’t control car drivers actions, you can control your own (see next bullet).

      By far the most common cause of accidents however, is drivers simply not seeing cyclists. Make yourself as visible as possible. Reflective clothing, and plenty of (flashing) lights if riding in poor light conditions. You may not look sleek and sexy, but neither does having your insides splashed across the tarmac.

    3. Keep Your Head
    4. A disproportionate number of male cyclists are killed compared to female cyclists – Male cyclists tend to ride faster, and take more risks.

      Don’t. You’re on a commute, not the Tour de France. Set off earlier and take your time. Though of course a significant number of these deaths are likely recreational riders on country roads, not commuters.

      (Also, interestingly, it could be partly down to driver behaviour, who may give less room to men than women when passing)

      On the flip side, a hugely disproportionate number of female cyclists are killed in London, usually by large vehicles turning left. (In 2009 for example, 10 out of the 13 cyclists killed in London were women, 8 of them killed by HGVs).

      Consider taking a cycling proficiency course, particularly if you don’t hold a driver’s or motorbike licence.

      Always presume that cars haven’t seen you – that car in the side street IS going to pull out, the car coming towards you is going to turn right regardless, and so on. It’s better to slow down needlessly than come to an abrupt and unwanted halt when they collide with you!

    5. Avoid Routes with HGVs
    6. HGVs account for around 1 in 5 cycling deaths, typically when turning left at junctions.

      Avoid routes with lots of HGVs, and don’t let yourself get sandwiched between them and the curb, particularly near a junction!

    7. Use Your Common Sense
    8. If your route to work feels dangerous – there’s a lot of fast or heavy traffic, bad junctions, you feel exposed – it’s very probably not worth the risk. Try and find an alternative route, even if it’s much longer and slower. If that’s not possible, cycle commuting is probably not the answer.

      Perhaps counter intuitively, this rider is at greater risk than someone on a city commute Pexels / Pixabay

      Good Reasons to Cycle to Work

      So, cycling to work may not be a fool-proof way to increase your life expectancy, but that doesn’t mean that there aren’t other excellent reasons to do it.

      The following are my top reasons to commute via bicycle:

      1. It’s Fun
      2. My main reason for cycling to get from A to B, is that I enjoy it.

        Irrespective of whether the journey time is longer or shorter than the possible alternatives, the journey is much more pleasurable.

        It’s hard to put into words exactly what it is about cycling that is so satisfying – the journey just seems to flow by.

        Of course, the pleasure of the ride depends greatly on the route – referring back to the final point in the last section – if your route is stressful and you don’t enjoy it, don’t do it!

      3. It’s Fast
      4. There’s no queueing in traffic (or very little) on a bike, especially if you’re in an area with good cycling infrastructure.

        There are few things more satisfying than whizzing past huge queues of stationary traffic on your bike…

      5. It’s Time Efficient
      6. Even if your commute might take a bit longer than were you to do it in a car or public transport, it can still save you time.

        Perhaps you can drive to work in 20 mins, rather than a 30 minute cycle.

        With the cycle commute however, you’ve effectively achieved 60 minutes of exercise while only “losing” 20 extra minutes of your day (or you’ve gained 20 mins of fun depending on your perspective!).

        Getting sufficient daily exercise is crucial for long-term health and wellbeing, both physical and mental.

        If you drive to work, you’ve still got to get that 60 minutes elsewhere. Not always easy.

        Indeed, the researchers note in the study in question, that in general, it was only those that cycled to work who got close to achieving daily exercise targets, and that it was basically this that accounted for the results.

      7. It’s Cheap
      8. You can get a serviceable bike from as little as £50. Insurance is a fraction of the cost of car or motorbike insurance (though it’s not obligatory, it is advisable), there’s no road tax and no fuel to pay for. Maintenance fees are negligible and you can repair most things yourself instantly at the side of the road.

      9. It’s Green
      10. Cyclists don’t contribute to greenhouse gases (well maybe some of the vegan ones do a little), and when a bike comes to the end of its life, it creates much less waste, and much safer waste, than does a car.

      11. It’s Safe
      12. Yes, there is a small risk that comes with cycling for the rider. I really must stress however, that it is very small, and if you follow the safety rules listed above, they are almost negligible. But here I’m actually referring to the safety of others!

        The car has been described as “The World’s Most Dangerous Machine“, with car drivers being responsible for millions of deaths every year worldwide.

        By choosing to cycle, you vastly reduce your risk of killing someone else.

        The more people cycle, the safer the world is for everyone, cyclists, pedestrians and even motorists.

      Sue decided to leave the RangeRover at home today PublicDomainPictures / Pixabay

      Final Thoughts

      I hope that this post hasn’t needlessly scared anyone off cycling.

      I must stress again, the risks are very small, particularly if you’re sensible, and though the physical health benefits may have been over played a little in the study, this is not to say that they don’t exist.

      What I would like to do, however, is reframe the question a little, to give a different perspective.

      The study claims that cycling to work reduces risk of heart disease, cancer and all cause mortality.

      Could it then be said that commuting to work by other means increases your risk of heart disease, cancer and all cause mortality?

      It’s all very well to compare one form of commuting to another, but how about commuting vs not commuting?

      Personally, I think commuting is a huge waste of life.

      The average commuting time in the UK is 1 hour per day, though 1 in 7 face a commute of 2 hours or more! That’s 5 to 10 hours per week.

      The worst case scenario, in my opinion, is doing this commute in a car, crawling start stop in traffic, the stress and boredom only occasionally punctuated by the occasional impact with a cyclist/pedestrian/animal/other motorist on the way…

      Yes, if you can do some or all of your commute on a bike, it can make it more pleasant and count towards your daily exercise goal, but wouldn’t it be better to not have to commute at all? You could use the time you’ve saved to go on a bike ride on the safest most pleasant route of your choice, pick different varied routes, or do a different physical activity altogether.

      Rather than urging Dave to commute to work by bicycle in order to improve his health and longevity, I’d urge him to do everything he can to reduce his commuting to as near zero as possible.

      Encourage your employer to let you work from home some or all of the time, or use co-working spaces closer to home (also flexi hours to avoid peak traffic times). If this doesn’t work seriously consider alternatives closer to home (or that will let you work from home). If you have the prefect job, but you simply have to be there, move yourself closer to it.

      Very few people have the perfect job of their dreams however, and quite possibly the 40+ hours you spend working are as big, if not bigger, waste of your time, and harmful to your wellbeing, as the commute itself.

      Rather than worrying about the effects of how you get to work and back on your health and wellbeing, perhaps it would be better to focus on much more profound changes – i.e. avoiding the daily commute and the 9-5 (or 6, 7, 8…) altogether.

      Complete madness? I’m not saying that it’s easy, or that everyone can achieve it. But it’s not impossible either. I’d strongly suggest reading The Four Hour Work Week by Tim Ferris.

      Even if you can’t imagine 4 hours a week of work and zero commute right now, think what a difference reduction to 30 hours a week and a 15 minute commute by bicycle could make to your life. That’s an extra 14 hours per week for yourself/your family.

      Or at least that’s how it starts – you’d be amazing how much more creativity, ingenuity and head space that extra time gives you, which in turn you can use to create yourself more extra time, and so on…

      This article was written by Simon Whyatt and first appeared on the blog Live Now Thrive Later.




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