The Miracle Pill

by Peter Walker

  When, in the more distant past, people wanted to rest for a period, a common method was to squat on their haunches. This is something occasionally seen today, but generally only in parts of East and Southeast Asia. The majority of chair-habituated adults tend to find squatting for any period fairly uncomfortable. From the bitter professional experience of trying to perch just above a wet pavement but out of the view of TV cameras to take notes while a politician gives a statement, I know I can generally last only a few minutes without having to shift. Cregan-Reid argues that years of daily sitting has so shortened most people’s hip flexors, the bands of muscle around the joint, that their pelvis is permanently tilted forwards, even when standing – an adaptation he believes contributes to the epidemic of back pain in many nations.5

  The rise of the chair as the default support for the human body has happened on two fronts. In the home, comfortable upholstering using fabric emerged in the early eighteenth century, particularly in the French royal court, even though a combination of cost and generally damp houses limited its initial spread. Far more influential was the Industrial Revolution and the dawn of the seated, urbanised workforce. English census figures show the pace of change. Between 1851 and 1871 the number of commercial clerks shot up from just under 44,000 to more than 91,000. Office work still remained a minority occupation in an era with more than 110,000 blacksmiths and a million-plus servants. But the trajectory was obvious. In 1851, England had almost 1.5 million farm labourers and shepherds. Twenty years later that figure had fallen to 980,000.6

  And now? In many countries, sitting down has become the norm for large parts of the day, both at work and during leisure. Precise figures vary, not least because much of the data is self-assessed, but various surveys have claimed common figures for the UK of up to nine hours of sitting time a day,7 a figure matched by estimates in places like Australia.8 The most recent NHS figures are slightly less dramatic, saying that around a third of adults sit for six hours a day or more on weekdays, with a slightly higher figure at weekends. An international study, which took data from twenty countries, found an average daily sitting time of five hours. This varied between countries, with Portugal, Brazil and Colombia reporting averages below this, while Norway, Japan, Saudi Arabia, Taiwan and Hong Kong saw greater than six hours.9

  What does seem common is that when the researchers are able to actually measure how long people are immobile, rather than just asking them, the hours involved start to rise. US researchers enlisted more than 8,000 middle-aged and older people to wear a movement-monitoring device during the day for up to a week. It found that sedentary behaviour took up more than 75 per cent of people’s entire days on average, totalling more than eleven hours. In contrast, those tested were lightly active, for example standing up or walking around, for about three hours a day, and managed an average of around eighteen minutes of moderate or vigorous exertion. The authors did note that this particular set of figures could be higher than the US average because around half the data was collected in the chillingly named Stroke Belt, a collection of southeastern states including Alabama, Kentucky, Tennessee and North and South Carolina which suffer particularly high rates of both strokes and early death, something closely connected to poverty levels as well as inactive, sedentary living.10

  For all that the idea of active applause made me think about sitting down, it’s fair to say it still didn’t make much of an immediate dent in my behaviour. Soon after learning about it, I moved into the specialism of political journalism. This was in the aftermath of the UK’s Brexit referendum, a period involving two general elections, two changes of prime minister and near-constant drama and chaos. It certainly felt to me like I was spending a long time sitting in my office chair, typing up the latest developments. But how long?

  So, again, I decided to become my own research subject. To make sure the data was robust, it couldn’t just be about me making estimates. So I went in search of some technology. There are plenty of mass-market activity trackers that will try to assess how many minutes a day you have spent sitting down, but they tend to have drawbacks. Phone apps are, as we saw with the data in earlier chapters on step counts, reliant on someone carrying the device. But more than that, in measuring activity, both smartphones and wrist-based trackers like Fitbits, as well as the Garmin smartwatch I borrowed to measure my heart rate, use in-built accelerometers, sensors which measure acceleration forces, and thus movement. To work out whether someone is sitting, standing, walking or running, this raw data must be interpreted, and to an extent it depends where on the body the device is located. This makes phones, at best, approximate arbiters of step counts, let alone sitting time. Even wrist-based movement sensors have their limitations in this regard. In a break writing an earlier part of this chapter, I remained sitting down but spent a minute or so swinging my left arm back and forth, promptly registering another hundred-plus steps for the on-screen daily tally. I needed something accurate enough to be used in laboratory tests.

  Internet searching led me to the website of a small Danish company called Sens, which manufactures tiny devices that look a bit like the plastic security tags you see on clothes in shops, but much smaller, weighing just seven grams.11 Using a bespoke plaster they are attached to the outside of the thigh, just above the knee, where the measurements for acceleration and angle can be much more easily translated into accurate assessments of walking, standing, sitting and other behaviours. They are waterproof and can be left on for days, even weeks at a time. Intrigued, I sent a speculative email to the address listed on the website, explaining that rather than being a university researcher hoping to buy a few hundred sensors (their usual customer), I was an author who wanted just one sensor, for me. Oh yes, and I didn’t really know what I was doing. I was doubtful how interested they would be.

  A few days later, however, the company’s joint founder, Kasper Lykkegaard, emailed back to say they would happily sell me a single device, with full technical support, for a bargain price. He even arranged a video call so he could talk me through how to attach the sensor and access the data. It stores up to two weeks’ information at a time, which can be downloaded to the company’s website, via the intermediary of a smartphone app. If you are a professional you can see this in raw accelerometer form, or a graph showing the angle the device is pointed at over time.

  Luckily for me the website also turns all this information into an easily digestible 24-hour rolling bar chart. Each hour is split into fifteen-minute chunks which then rise upwards, divided in turn into various bands of colour, depending on what the wearer has been doing. Standing is marked in blue, walking is orange, and what is termed intermittent walking – what you might call pottering around – comes as a sort of yellow. The most satisfying colours are a bright green for running, and a darker green to indicate cycling. And then there is sitting or lying, represented as a blank, featureless grey.

  Luckily, I obtained the sensor some weeks before the coronavirus emergency began in the UK, and so I was able to wear it for a few weeks during my normal pattern of working. One of the rules of science is that when something is observed it necessarily changes, so I decided to, essentially, attach the device to my leg and try to forget about it. It was so tiny that this was just what happened. Of course, I can’t rule out some half-conscious awareness that might have made me more likely to, say, break up a prolonged period in my chair, but in general this felt like the natural, workplace me.

  When I did examine the results, even though I knew I had a job where I could and should stand up more, there was still a significantly larger mass of sedentary grey on the charts than expected. One immediate contrast was the difference between workdays and weekends. The latter showed occasional sustained periods of sitting, mainly at mealtimes, and again later in the evenings. But for the most part, it was continually broken up by flashes of colour to indicate walking and standing, even brief bursts of vivid green for running, mainly playing football in the local park with my son.

  In
contrast, the charts for workdays were much more drab, even given the morning-and-evening periods of cycling green for my commute. This was a fairly relentlessly busy news period, amid the combined news pressures of the latest Brexit fallout and the build-up to coronavirus. But it seemed no more busy than the rest of the near-four years I have spent reporting from Westminster, and so the sensor data was probably typical. As such, it was pretty depressing.

  Yes, there were fairly regular periods of walking, every day. Weeks earlier, Downing Street officials had changed the location of the twice-daily briefing with the prime minister’s spokesman, moving it from inside parliament to an office in 11 Downing Street, an extra ten-minute walk away. We had cursed the inconvenience at the time, but looking back at my activity record, it did at least generate a reasonably long orange bar for walking. But the later the chart went into any workday, the longer and more damning became the grey gaps between bursts of movement. Even in the internet era, newspaper time pressures tend to tilt towards a late afternoon deadline to deliver copy for the next day’s physical paper, and after lunch it was common to see two-hour periods in which I had clearly been out of my office chair not once, or very briefly, just sitting there, typing. Overall, the whole period from about 2pm to 6:30pm or so tended to be a long line of grey.

  Seeing my days presented as such an eloquent, easy-to-understand activity chronicle was simultaneously fascinating and alarming, and sometimes in ways that highlighted other sedentary aspects of modern life, those outside the office. For example, the day I travelled to Copenhagen to interview Jan Gehl, whom we heard from in Chapter 5, I spent much of it walking and cycling around the city, splashing the chart in satisfying orange and green. But it also showed a long, unbroken grey period when I was sitting down on the flight from London.

  The Sens software allows you to download the full data as a chart for each day, with a combined total for each type of movement, and a step count. It’s fair to say the picture, particularly for workdays, was mixed. I would rack up half an hour or so of cycling – my actual commute takes more like thirty-five minutes there and back, but waiting at traffic lights and junctions would be measured as standing – and my step count would somehow generally top 10,000. On my day tramping around Copenhagen I amassed a barely plausible 20,000 steps. But then there was the sitting. Here, the data showed two problems. Firstly, there were prolonged immobile periods, not broken up by standing or walking, a pattern which, as we’ll see later, is believed to be particularly hazardous.

  Also, there was the sheer amount of sitting down. The sensor does not distinguish between sitting and sleeping, but captures every single sedentary moment, from a brief sit-down to an office chair marathon. And, for me, it really added up. Even after discounting the time spent in bed, I would regularly clock up nine hours or more of immobile time every workday. Even on what looked like busy, active weekend days it could easily reach five or six hours.

  I was officially sedentary. Yes, I was also active, at least by government guidelines – as we saw in Chapter 5, my commute into work alone takes me well above the minimum thresholds. But in health terms, did the latter cancel out the former? I needed to find out.

  Throw away your television

  The physiological reasons why prolonged sitting is bad for you are very similar in many ways to the risk factors for inactivity in general, but to an extent they are more condensed. We saw earlier how regular movement helps your body transport and process different types of fat, including high-density lipoprotein cholesterol (HDL) – the ‘good’ cholesterol – and variants linked with poorer health outcomes, mainly low-density lipoprotein cholesterol (LDL) and triglycerides.

  The significance of prolonged sitting is that it puts some of our biggest muscles, notably in the legs and the back, into a cellular process known as downregulation, during which they produce less of certain proteins. These muscles are among the sort known as ‘red muscles’, so called because they are rich in capillaries, and are resistant to fatigue. They contain disproportionately high levels of lipoprotein lipase, which has a major role in breaking down triglycerides.

  Low-intensity activity, such as standing up or walking around, is a biological signal for this work to take place. If someone stays sitting down, this fat processing doesn’t happen properly, bringing a greater risk of cardiovascular disease, as well as excess weight. A body which does not properly break down triglycerides also has a higher chance of being unable to correctly process glucose, which is the path leading towards type 2 diabetes.

  At the most basic biological level these risks have been demonstrated using unpleasant-sounding laboratory experiments in which rats had their rear legs suspended above the floor for sustained periods over eleven days. The scientists found that these underused leg muscles ended up with significantly lower levels of lipoprotein lipase than those of rats not subjected to the regime.12

  While researchers are not permitted to treat human volunteers in quite the same way, reading some academic papers it can sometimes be hard to notice much of a difference. Numerous studies have used what is usually known as ‘bed rest’ – lying down for as much of the day as possible beyond basic bodily functions – to show the numerous ways that complete sedentariness affects the body. One 1968 experiment, which would presumably struggle to pass ethical guidelines now, saw five young American male volunteers spend a marathon twenty continuous days in bed. At the end of this, their fitness was almost a third lower than at the start, and even their hearts had shrunk by 11 per cent. Luckily, the researchers then put them all through an eight-week fitness programme, which undid the damage.13

  In population-wide terms, the consequences of prolonged sitting are also well proven, and the risks are many. A massive study published in 2018 tracked more than 127,000 US men and women over an average of twenty-one years, assessing them on the basis of non-work sitting. Those who averaged six hours or more sitting per day had significantly worse health prospects than those whose average was less than three hours. For more habitual sitters, the study concluded, the risks were higher in terms of dying for any reasons, and for acquiring cardiovascular disease and strokes, cancer, diabetes, kidney disease, chronic obstructive pulmonary disease (COPD), liver disease, digestive problems, Parkinson’s, Alzheimer’s, musculoskeletal disorders, nervous disorders and suicide.14

  This is quite a list, even if it is perhaps fair to argue that, even with other variables factored out, prolonged sitting can still be a decent proxy for more general inactivity. One particular academic focus over the years has been on the perils of watching television, and the conclusions are more or less always the same – the more you watch, the worse your chances.

  A UK study with a cohort of just over 13,000 people in Norfolk found that after the standard adjustments for other factors, each one-hour increase in average daily viewing time increased people’s overall chances of death during the study by 5 per cent, and the risk of cardiovascular disease by 8 per cent.15 Other research has indicated that the risks can then escalate. A US paper which tracked more than 220,000 fifty-plus adults for an average of fourteen years found that when compared to those who watched less than an hour a day, people who averaged three and a half hours – which, the researchers noted, is the norm for 80 per cent of Americans, taking up half their entire leisure time – had a 15 per cent higher chance of death for any reason over the course of the research. For the group who racked up an admittedly formidable seven hours or more a day, the additional mortality risk went up to 47 per cent. This covered eight separate increased health risks: cancer, cardiovascular disease, COPD, diabetes, flu or pneumonia, Parkinson’s, liver disease and suicide. ‘There was no cause of death where TV viewing was protective,’ the authors added, perhaps unnecessarily.16

  According to Dr Katrien Wijndaele, an epidemiologist and research scientist at Cambridge University, who led the Norfolk study, television viewing tends to show a generally worse series of health outcomes even compared to other sedentary behaviours, for
example office work. There are, she says, several theories as to why this might be the case, all of which could be at least partly true. One, she explains, could be because, as mentioned earlier, watching a lot of TV ‘is just one of those behaviours that tends to be higher in people who also show many more other unhealthy behaviours’, and that studies are unable to properly account for all these other activities. Connected to that is research showing that when people watch TV they are more exposed to advertisements for unhealthy foods and snacks, which could affect their diet and thus further embed their existing non-TV health risks.

  On a biological level, the bulk of TV viewing tends to happen in the evening, generally after people have eaten their biggest and most sugar- and fat-laden meal of the day. As we have seen before, being inactive in this so-called postprandial state can worsen the way our bodies process fats and sugars, with long-term results for our cardiovascular systems and chances of moving towards pre-diabetes.

  There is a final theory: all sedentary time is more or less equally bad, but TV watching comes across worse in the studies because it’s the only one that people report correctly. ‘We find that TV viewing tends to be recalled better by people, because it’s done in a very habitual way,’ Wijndaele says. ‘People basically remember programmes they watch, and so they can fairly accurately report on levels of TV viewing, more accurately compared to other types of sitting. Sitting is something we do throughout the day. We can’t remember when we go and sit down, when we get up again. So if you ask people about a total estimate of their sitting time, or even of other, more specific types of sitting, it’s a lot harder to recall those. So if you then have to come up with a total estimate of sitting time, they tend to be less valid and reliable than estimates of TV viewing time. So that is one factor that could explain why we find those stronger associations for TV viewing.’17