Progress, generally defined as a higher standard of living, more advanced education, and better medical care, is commonly thought to be a positive. Yet a new international study found that one aspect of progress, specifically the ownership of televisions, cars, and computers, is linked to higher rates of obesity and diabetes in lower and middle income countries. "There was over a four times increase in the rate of obesity and about a 2.5 times increase in the rate of diabetes going from owning none to owning all three devices in these houses,” Dr. Scott Lear, a member of the faculty of Health Sciences at Simon Fraser University, told Medical Daily. "So that’s quite a remarkable difference."
Global increases in rates of obesity and type 2 diabetes have largely been among high income countries, where these are commonly referred to as lifestyle diseases. This umbrella term encompasses any disease that can potentially be prevented by changes in diet, lifestyle, and environment, and would include heart disease, stroke, and osteoporosis. Generally, if each of us were to eat the appropriate amount of healthy foods, avoid toxins like alcohol and cigarettes, all while exercising daily, we would substantially decrease our risk for obesity, certainly, and other lifestyle diseases. The reason certain diseases proliferate in high income countries may be attributed to various factors including high availability of processed food and the increased potential to avoid physical activity due to modern conveniences — among them, cars and TV. Why walk when you can drive? Why play a sport yourself when you can comfortably sit and watch athletes on TV?
Granted, this is somewhat of a simplification. Lives are shaped by livelihoods and, increasingly, many people have jobs where they spend more time inactive. For instance, a recent study found that fewer than 20 percent of jobs in the U.S. involve physical exertion — years ago half of all private-industry jobs, such as manufacturing, farming, and construction, involved physical activity. Add to this the fact that American employees often spend nine hours a day or longer at work. Many industrious people, then, sit for a solid portion of their day, and this is true not only in America but in developed nations across the globe.
Meanwhile, low and middle income countries are becoming more industrialized, and so their populations are expected to become similarly sedentary. Will this mean an increased risk of lifestyle diseases? A team of international researchers, led by Lear, who is also a faculty member within the Division of Cardiology at Providence Health Care, Vancouver, decided to find out.
International Health Study
The research is actually a subset of an international and observational analysis known as the Prospective Urban and Rural Epidemiological or the PURE study. The intention of PURE is to look at the causes of chronic disease and to investigate the impact of factors such as urbanization and economic status as well as societal policy and access to health care. For the current study, Lear and his colleagues specifically, “wanted to look at how the home environment led to the risk factor for these diseases.” The team, then, collected data on 153,996 adults in 107,599 households from 17 countries enrolled in PURE. Of these, 10,000 participants came from Canada — more than a quarter from the Vancouver area — with others from:
- Sweden, United Arab Emirates (high income)
- Argentina, Brazil, Chile, Malaysia, Poland, South Africa, Turkey (upper-middle income)
- China, Columbia, Iran (lower-middle income)
- Bangladesh, India, Pakistan, Zimbabwe (low income)
The researchers asked participants whether they owned a TV, computer, or car, and then they asked to characterize their physical activity, sitting time, and diet. Participants also reported on their health condition, including whether or not they have diabetes. Finally, the researchers measured both height and weight. What did they discover?
TVs were the most common device owned by households; over three quarters of all households owned at least one TV, followed by about one-third owning a computer, and just under a third owning a car. Ownership of devices appeared to be more heavily concentrated among those in urban areas of middle and low income countries compared to those in rural areas. In low income countries, the study linked owning all three devices with a 31 percent decrease in physical activity, 21 percent increase in sitting and a nine centimeter or a roughly 3.5 inch increase in waist size compared with those who owned no devices. The prevalence of obesity increased from 3.4 percent among those owning no devices to 14.5 percent for those owning three devices. The prevalence of diabetes also increased such that those owning no devices had a 4.7 rate of diabetes, compared to those who owned three devices and had an 11.7 percent rate of diabetes.
Overall, in low income countries, those who owned these devices have over four times the rate of obesity and about 2.5 times the rate of diabetes compared to those who do not own these devices. And what about high income countries?
The same is not true of people living in high income countries and when asked about this “plateau effect,” Lear said, “What I mean there, for lack of a better term, is the damage is already done.” The negative impact, then, of these devices on health may have already occurred and are already reflected in the high rates of obesity and type 2 diabetes. “We’ve been exposed to cars, TV, and computers for decades now.”
Nevertheless, the study holds great fascination for those who live in high income countries. “When we look at a cross-sectional study, when we look across countries at different periods of development, it’s almost like looking at North America and going backward in time,” Lear said, adding that looking at these low income countries, is “like 50 years ago for high income countries.”
He adds a single caveat, though: “Accumulation and use of these devices is happening at a lot faster rate than it ever did in the high income countries.” And this is hugely significant because these lower income countries are still dealing with things like large portions of their population being undernourished and the spread of diseases long unfamiliar to residents of high income countries. “It’s almost like in the lower income countries their health care systems are less robust and they’re now being squeezed at both end,” Lear said. “When change happens so fast, it’s harder for policies and governments and regulations to keep up with that pace.”
For these reasons, lower income countries may soon be facing the same obesity and diabetes epidemics as their higher income counterparts. Noting that “it’s not as if anyone would be going out and telling people to not buy these products or use them,” Lear suggests it’s important for public health officials to establish policies that inform people of the health “dangers” involved, say, in sitting and watching TV for too many hours each day.
Going forward, Lear will be changing the angle of his camera in order to shift his field of vision. “We are interested in looking at the community environment as well as what’s in the household,” Lear said. “Are there sidewalks? Is the neighborhood safe? Are there parks or fields or community centers, and similarly what about healthy eating? Is fresh fruit available or are there fast food restaurants?”
Source: Lear S, Koon T, Gasevic D, et al. The association between ownership of common household devices and obesity and diabetes in high, middle and low income countries. CMAJ. 2014.