Sitting: is it really the new smoking?

Sitting: is it really the new smoking?

Here’s what the science says so far: there is very possibly something wrong with sitting. Or maybe not.

Discover the underbelly of the sitting debate where people make ridiculous statements, the media calls everything the new smoking and scientists don't agree on definitions.

On the surface, debating the meaning of sedentary behaviour may appear semantical in nature, but definitions matter when you are investigating how to prevent disease and keep entire populations healthy.

On this wacky journey, we’ll get you up to speed on the fantastically odd scandals in the sitting science community, media mudslinging and wild statements. You'll also get a comprehensive overview of what disease risks are influenced by sitting when you take the Atlas Biomed Health Questionnaire and why.

So get ready for a winding path of science titbits written for the average human truffled with outlandish behaviour in the strange world of sedentary behaviour science.

Sitting: it’s very controversial

Scientists aren’t known for vocally indicting governments or media, especially since funding is hard to come by without a sexy pitch. And let's face it, we all instinctively know a few things:

  • we probably do sit too much, both as individuals and nations
  • we could definitely probably get some more exercise
  • life would probably be better if we weren't desk-bound for most of it

And that's probably what several governments thought when they published public guidelines about sitting. It hasn't helped that media has adopted the anti-sitting banner like cheerleaders at a basketball match: all frills, no substance.

It is the combination of poor evidence about the ills of sitting, clickbait journalism and the eye-watering quotes of one American doctor that has the medical research community teetering on the brink of an aneurysm.

Most recently, a 2019 review of research and state guidelines decried public health recommendations, calling them premature and lacking hard evidence for telling people to break up their sitting with short breaks. But why does this matter?

Because the authors nailed the controversial areas of sedentary science and we are going use their public dissent to dissect the many disputes of this topic. One could be forgiven for assuming that sitting is a pretty natural human inclination: just add a chair and hey, presto. Unless you work for the county council, in which case, you may prefer a good shovel and a nice long lean.

The study has a very boring title, but authors with credentials. The lead researcher was E. Stamatakis who is no shrinking violet in the field of disease risk and sedentary lifestyle patterns. His team cite good reasons for vocalising their disapproval of blanket statements for the masses mostly “consisting of messages to sit less and break prolonged sitting times”.

This is because, while it seems likely that sitting does indeed increase the risk of certain diseases, there is no consensus in the scientific community over what constitutes sedentary behaviour. For many (and government officials), it often just means “sitting too much”, but it's a bit more complex than that. It actually includes any waking activity in a sitting, reclining or lying down posture.

☝️FACT☝️ The definition of sitting is a source of such antagonism that in 2017, two researchers actually published a paper called Is sedentary behaviour just physical inactivity by another name?

Words, words, words

Let's think about this for a second. Is sedentary behaviour merely the act of lounging for hours on end like an extra family member in Downton Abbey? Is it unhealthy to spend 8 hours chained to your desk if you run a few miles every other day and ride your bike to work?

Perhaps it’s the Sunday night cake-eating RDV in front of the Great British Bake Off that's bad for us? But is it really bad for us if it's a raw vegan cake made from bananas, nuts and beetroot? And how about binge-watching Netflix every weekend because we have a hangover from Friday?

In all these examples, there are several confounding factors that are known to influence health: physical activity (or lack thereof), TV watching, diet, mindless snacking and alcohol consumption. The problem is that, as average humans, we tend to lie about these things to ourselves and researchers, extrapolating the good and omitting the bad.

This makes it very difficult to study humans in their natural environment. And therein lies the issue within the medical research community: it’s extremely hard to dissociate sitting from the rest of life - and that’s exactly what my geneticist colleague confirmed.

These confounding factors lead to friction between research methods and criteria that make it very difficult to establish public health guidelines on the mere act of sitting.

However, lack of consensual best practice in research methods puts the validity of the scientific findings in peril. Combined with premature public messaging on the sedentary behaviour and a doctor with very quotable material, and it's no wonder the media made sitting enemy number one.

Claim it til you make it

Scientists really hate being misquoted, especially by not-so-scrupulous media. In fact, some even went as far as investigating the media’s claims of sitting being the new smoking in a study called Hyping health effects: a news analysis of the ‘new smoking’ and the role of sitting. Somehow, we feel like this probably didn't make the news.

And for an academic paper, what a zinger it was. The no-holds barred commentary started by dryly pointing out that: “No scientists were quoted as saying ‘sitting is the new smoking’ specifically.” However, one doctor from the Mayo Clinic was indicted for his encouragement of the media.

Dr James Levine appeared in 10% of such stories making surprisingly pungent statements on a topic he is clearly very passionate about. According to this man, “Sitting is more dangerous than smoking, kills more people than HIV and is more treacherous than parachuting. We are sitting ourselves to death.”

Now, working with researchers on a daily basis has taught this writer one simple truth that can apply to sitting, exercise and the makers of brash claims: everything in moderation, please.

So is sitting really the new smoking?

A few scientists actually answered this exact question in a study helpfully named: Is sitting really the new smoking? And the basic conclusion is, well, no. That’s not to say sitting is good for you - it’s just not quite the killer that tobacco is.

But firstly, the authors would like to point out that it is wrong to compare an addiction (smoking) to a habit (sitting), because addictions come with cravings and impulses to engage in behaviours that are bad for your health.

They also soundly lambaste media for extrapolating the risks of sitting and therefore shirking their responsibilities to report accurately. After all, the media is the leading source of health information for most people. In the words of worried researchers, “equating sitting with smoking is unwarranted, misleading for the public, and may serve to distort and trivialize the ongoing and serious risks of smoking.”

Estimates of the team that published this research indicate that there is about 190 excess deaths in people “with the highest volume of sitting” versus those with the lowest. Compared to 2,000 excess deaths per year among the heaviest smokers versus the “never smokers”.

As one 2015 systematic review and meta-analysis on disease risk, hospitalisation and mortality for sitting put it: “prolonged sedentary time was independently associated with deleterious health outcomes regardless of physical activity.” So basically sitting down too much is still bad for you. But it’s not the new smoking.

However, there is one chronic, preventable and widespread disease that does seem to thrive on sedentary behaviour. Sitting appears to be most likely to increase your risk of diabetes type 2, a finding confirmed by several studies.

Sedentary diabetes risk

According to the authors of Is sitting really the new smoking?, sedentary behaviour “almost doubles the risk of type 2 diabetes, but only increases incidence and mortality risk associated with other common chronic diseases by approximately 10% to 20%.”

Research has turned up evidence that bouts of movement improves post-meal glucose and insulin responses. This means that movement helps the body manage the influx of glucose that is absorbed following a meal. The body’s muscles help lower blood glucose levels by drawing it out of the bloodstream as a source of fuel for their activity (ATP).

Furthermore, regular exercise actually trains the cells and makes the tissues more sensitive to glucose. This can reduce insulin resistance that is diagnosed in type 2 diabetic patients and people with prediabetes. In short, the more active you are, the better your muscles function and the better your body can deal with glucose.

So it's not really about sitting after all. It's time to change the dialogue from the static consideration of sedentary behaviour to the more dynamic investigation of movement.

The sitting decoy: it's all about exercise

Physical activity isn’t just good for preventing diabetes, it also lowers the risk of argument among researchers. As we’ve established, it’s very hard to evaluate sitting independently from other factors.

But scientists are relatively satisfied with their methods for measuring the effect of physical activity on disease, like frequency of activity, intensity and things like “hours spent” performing specific exercises.

These methods are even used to assess how exercise impacts the gut microbiome. Incidentally, that too responds positively to exercise and negatively to lounging.

So, as a general rule, the best predictor of health outcomes in the field of sedentary behaviour is actually physical activity. Low physical activity (but not necessarily the act of sitting) increases the risk of several chronic conditions that are preventable and associated with premature death:

  • Diabetes type II
  • High blood pressure
  • Cardiovascular events

The association with cardiovascular events like heart attacks and stroke is not straightforward, but lack of physical activity alone is known to increase blood pressure. Scientists think that lack of movement doesn’t train the cardiovascular system to respond adequately to physical stress.

Simply put, doing sports trains your blood vessels to dilate and your heart to pump more in order to deliver oxygen and glucose to your muscles. So if the body isn't used to physical strain like movement, then the blood vessels aren’t responsive: they can’t stretch to accommodate the extra blood pumped by the heart in response to effort.

In addition, other factors like excess glucose circulating in the bloodstream, caused by insulin resistance, or high levels of cholesterol can damage the lining of your arteries. This makes them narrower and less flexible, thus contributing to high blood pressure.

Gogglebox on trial

The authors of Is sitting really the new smoking argue that TV and physical activity are the best predictors of disease risk according to their meta-analysis. In particular, the study fingered the TV as the most dangerous belonging in modern households:

“Watching TV for 3 h or more per day was associated with increased mortality, regardless of physical activity, except in the most active [people], where mortality was significantly increased only in people who watched TV for 5 h/day or more.” In essence, even the most active people put their health and wellbeing at risk by watching too much of the gogglebox.

When they ran the numbers of other studies, the team also found that activity level alone also influences a person’s mortality risk. Basically, people who did the least exercise and spent the longest time sitting were most at risk. However, those who combined 8 hours of sitting with high levels of physical activity didn't have increased risk of mortality.

And so consensus grows among doctors and researchers at the forefront of medicine on one point: lack of physical activity is not good for your health.

Sitting and specific disease risks

In the Atlas Biomed offices, we have a team of geneticists, MDs and biostaticians that work a 9-5 job like the rest of us. And who better to ask about sitting than these overachievers?

After all, they have dedicated their lives to quantifying disease risk for the rest of us based on our DNA, environment and lifestyle habits, And here's what they say counts, and thus features in our disease risk algorithm among a myriad of other factors.

☝️TIP☝️ If you've taken the Atlas Biomed DNA Test, click on the disease to access your risk profile directly.

Disease The Science
Age-related macular degeneration Less than 2 hrs/week of exercise was associated with more drusen (fatty deposits in eyes), the first sign of age-related vision loss.
Alzheimer’s disease Physical activity was associated with lower risk of Alzheimer’s in people over 65
Gallstones Physical activity lowers risk of gallstones. People with low physical activity have the highest relative disease risk.
Gout Physical activity in men combined with healthy BMI, diets rich in fruit, low in meat/alcohol may lower the risk of gout.
High blood pressure Moderate and high levels of physical activity lower the risk of hypertension.
Diabetes type II Low-, medium- and high-intensity physical activity lowers the risk of diabetes type II
Coronary heart disease Physical activity in older adults, especially walking, can reduce the incidence of coronary heart disease and stroke
Crohn’s disease Physically active women are nearly half as likely to get Crohn’s as inactive women and have less “flares”.
Ulcerative colitis Physically active female patients have less “flares” than sedentary women.
Parkinson’s disease High and consistent levels of physical exercise appears to be protective against Parkinson’s

So when you fill out the Health Questionnaire, we use these data in our recommendations algorithm that identifies areas in your life that you can address to improve your health and wellbeing over the long-term.

For example, if you are at above-average risk of a disease that can be influenced by physical activity, and you're not getting enough exercise, then it will probably come up in the insights section of your profile,

Basically our system actually computes your self-reported frequency of exercise and intensity as well as sedentary habits based using the most reliable data in the field. We're not even telling you this to sell tests, but because it's the future, it's called preventive healthcare and it's really cool.

In Conclusion

At Atlas Biomed, working with a team of scientists comes with a simple mantra: everything in moderation, especially when you’re discussing the results of scientific research.

So sitting is probably bad for you, but researchers find it a lot easier to measure the benefits of exercise and the risks of not getting enough of it. And this whether you are chained to a desk or not.

Other researchers are making a case for a max 4-hour sitting work day with office workers progressively increasing their time dedicated to standing and light activity for the other 4 hours.

The dawn of team yoga sessions is still far off, but the same researchers think that reducing stress and improved access to higher quality nutrition could also help minimise the potential ills of workplace servitude.

And so, we must wait for more answers and better science on the art and artlessness of sitting. But it’s still probably best to turn off the Great British Bake-Off and give your cardiovascular system a good stretch with a nice walk in the park.

Sources:
Leigh Stewart
Leigh Stewart Head of Atlas Biomed content, trained chef and avid fermenter of edible bacteria.

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