Global study shows: a sedentary lifestyle is correlated with higher incidence of heart disease

As if it weren't too terribly obvious from that much-maligned common sense, a new global study of 29,000 people from 52 countries in Asia, Europe, North America, South America, Australia and the Middle East has shown:

mild to moderate physical activity at work, and any level of physical activity during leisure time reduces the risk of heart attack, independent of other traditional risk factors in men and women of all ages, in most regions of the world and in countries with low, middle or high income levels. Interestingly, heavy physical labour at work did not protect against heart attacks.... Furthermore, ownership of a car and TV, which promotes sedentary behaviour, was found to be independently associated with the risk of heart attacks.

And the authors were able to run the numbers of how much help light and moderate physical activity helps with reductions in heart attacks:

...they found that people whose work involved either light or moderate physical activity had a fifth (22%) or a tenth (11%) lower risk of having a heart attack when compared to people whose occupation was mainly sedentary. However, heavy physical labour did not reduce the risk at all. During leisure time, the risk of a heart attack was lower for any level of exercise when compared with being mainly sedentary, reducing by 13% for mild activity and 24% for moderate or strenuous activity.

Of course, physical exercise isn't the only thing that these people looked at. After all, it would be a waste of an opportunity to look at a panel of conditions for so many people. And some of the additional things that they asked questions about - in order to control for confounding in the population:

After adjusting for various confounding factors such as age, sex, country, income, smoking, alcohol, education, health, diet etc...

... and they found that:

People who owned both a car and a TV, both indicators of a sedentary lifestyle, had a 27% increased risk of a heart attack, compared to those who owned neither a car nor a TV.

So what is the take-home from this study?

The authors conclude that daily moderate physical exercise should be encouraged in everyone to prevent heart disease. Prof Held added: "The data have some real-life implications. One suggestion may be for the lower income countries to be more involved in promoting physical activity as their societies starts to use more labour-saving devices, so as to counter-act the inactivity that this can lead to; however, it also important to promote physical activity in all parts of the world."

To me, the basic lesson is a good one. However, I think that Prof Held seems to forget one of the greatest "labour-saving devices" that tends to get implemented once income levels rise: motorized personal vehicles (mopeds, motorcycles, cars, trucks). In so many places that have undergone "development", there has been a concomitant increase in personal motor vehicle use, a shift away from public transportation options (such as buses, bus-taxis, etc), which increases road congestion and increases public health problems caused by exhaust inhalation (exacerbated due to lax/nonexistent car exhaust laws/enforcement of such laws). Furthermore, increased personal motor vehicle use is also coupled with increased road fatalities and serious injury than predominantly public transport, bike, and walking transportation options. Furthermore, in the authors' study, easy walking was listed as "light exercise" (something that drastically diminishes with car and TV ownership) and walking and cycling were listed as "moderate exercise" (something that also drastically diminishes with car and TV ownership).

To me, it makes sense that doing more physical activity than effectively nil produces a more physically healthy body. Removing options for that will lead to costs that will need to be paid down the road (unless you happen to have good genetics or are really lucky). To that end, I'm kind of glad that I decided to purchase a good, study bike instead of a reliable used car; my 8-10 mile daily commute on that personal pedal-powered vehicle has helped me lose a decent amount of weight, lowered my resting heart rate, and likely helped in other ways that are less apparent.

(And when I was 10 years old, the idea of a personal robot that would do everything for me was soooo appealing. I suppose that if I did ever get a personal robot, it would have to also act as a physical fitness trainer; forcing me to do physical labor so that its help with alleviating my physical labors wouldn't be offset by the negative outcomes of a sedentary lifestyle that a personal robot would be designed to create.)