By: Valerie Miller, Ph.D.
Society is Messing with Your Sleep
There are a number of factors, such as work, personal habits and families, that determine how much sleep a person gets. Individual chronotypes, the sleep cycle an individual’s body naturally prefers, also affect sleeping patterns. However, a question that remains to be answered is: does society as a whole affect sleeping patterns? Researchers from the University of Michigan seeking to examine societal effects on sleeping patterns at the population level have published a study in the journal Science Advances that used smartphone data to track sleep cycles in different countries. The researchers created a smartphone app, called Entrain, which was designed to recommend sleeping times to travelers to help them deal with jetlag in new time zones. People who signed up for the app were also given the option to answer questions for research purposes, such as where they live, how much indoor or outdoor light they’re exposed to, their usual bedtime, and when they typically wake up. The study included data from over 5,000 app users. Shift workers were excluded from the analysis.
The researchers first created a mathematical model to determine what might be considered a “normal” bedtime and wake time for each user location, using local sunset and sunrise times. They then compared these times to the actual sleep and wake times reported by the users. They found that there were variations on a demographic level, with older people sleeping less and waking earlier, and with women of all age groups getting more sleep than men. At the society level, the researchers found that there was little variation on when people in different countries wake up, although people in locations with earlier sunrises tended to get up slightly earlier. However, major differences were found when people in different countries reported going to bed. In other words, in countries where people tend to get less sleep, such as Japan and Brazil, later bedtimes are the cause, not rising earlier.
The study did not delve into the particular reasons for why some societies have later bedtimes, but did discuss that oftentimes, wake times are more rigid than bed times, due to work and school responsibilities. With bed time, people have more control in deciding when they want to go to bed, which may be based on how tired one is, how much sleep one wants to get and what else is going on in ones’ life. However, when bedtimes are differing across societies, cultural reasons are likely the cause, but future studies will need to be performed to determine what those reasons are. (Julie Beck, The Atlantic)
Child Health Policy
Beware the Monkey Bars! Playground Concussions are Rising
According to a study by the Centers for Disease Control and Prevention (CDC), an increasing number of children have been visiting the ER due to traumatic brain injuries, including concussions, sustained at playgrounds. The study, recently published in the journal Pediatrics, looked at children between the ages of 0-14 who visited an ER in the US between 2001 and 2013. They found that the estimated annual visits to the ER due to traumatic brain injuries remained relatively stable between the years 2001 and 2008, with fewer than 20,000 per year. However, this number has steadily increased to approximately 30,000 estimated ER visits per year by 2013. Of all pieces of playground equipment, the monkey bars and swings were the two places where children suffered the most traumatic brain injuries, followed by the slides.
The CDC doesn’t have a clear answer as to what is causing the increase. One suggestion posits that children are playing on playgrounds that aren’t repaired or maintained enough. Another possibility is that due to a number of recent reports regarding concussions in professional sports, doctors, parents and teachers have an increased awareness of traumatic brain injury, leading to more diagnoses.
Although concussions are serious injuries, they represent a relatively small percentage of injuries that occur at the playground. A study by the Consumer Product Safety Commission determined that fractures were most likely, representing 40% of all playground injuries in 2015. Concussions accounted for 3% of injuries, and internal injuries that affected the head accounted for an additional 9.5%. (Leah Libresco, FiveThirtyEight)
How safe is bike commuting? Perhaps less than you think
While most people think of biking as a healthy way to commute that is earth-friendly and can be faster, cheaper and more reliable than driving or public transportation, it turns out that biking is a lot less safe than people realize. Of all methods of transportation, biking is the second most dangerous, with motorcycles claiming the top spot. According to a 2007 study published by the CDC, people in the US are twice as likely to die while biking than riding in a car per trip, and 500 times more likely to die per trip than taking the bus. In US cities, the addition of dedicated bike lanes and trails have helped to reduce fatalities. Washington, DC and Boston are safest large cities for bicyclists, with only 1.5 fatalities per million residents in 2014, whereas Tucson, AZ was the least safe, with 11.4 fatalities per million residents.
Accidents aren’t the only health risk that bicyclists face. Air pollution is another risk that affects bike commuters. A 2015 study by researchers at Colorado State University found that, on average, people commuting by bike inhaled three times more air pollution than drivers, caused by heavier breathing and longer commute times outside in the presence of cars.
Despite these factors, Johanna Boogaard, a researcher at the Health Effects Institute in Boston, argues that biking is still the best commuting option for overall health due to the benefit of getting regular exercise. In fact, using data from the Netherlands, a nation in which many people bike, Boogaard and colleagues demonstrated that the benefits of cycling (3-14 months of lifespan gained) outweighed the negative effects of accidents (5-9 days lost) and air pollution (0.8-40 days lost). Boogaard also was confident that the findings of her study would hold true in the US, a place where there are more traffic accidents, but where more people with inactive lifestyles could benefit from physical activity. (Sadie Dingfelder, The Washington Post)
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