There’s a major dearth of scientific information on sleeping surfaces.
Image: Masahiko OHKUBO/Flickr
In Western society, our definition of a bed is fairly narrow: a mattress, often with a box spring, a bed frame, fitted sheets, multiple pillows, duvets, comforters, the works. But around the world, people catch z's on a wide range of surfaces, from hammocks and thin bed rolls to bamboo mats, wooden cots, and even grass.
Considering as many as 70 million Americans suffer from sleep disorders or deprivation, it's tough to say for sure if our cushy nests are really preferable to simpler setups. Perhaps we'd be better off sleeping on the ground, How can we know what kind of sleeping surface is best for our health, our backs, and our rest? What does science have to say when it comes to beds?
Turns out, thanks to the fact that the mattress industry dominates and controls much of the research, science doesn't have a whole lot to say on the matter.
"The academic community has kind of felt that it's a business issue and not something they should be engaging in," said Dr. Andrew Krystal, a psychiatrist and sleep researcher at Duke University. "But I think that's a big mistake given that we're putting people on mattresses in research studies all the time and we haven't bothered to figure out if the mattress characteristics matter. I think it's a big hole in the scientific literature of sleep."
There's a serious dearth of any kind of solid scientific research on how the surface you sleep on affects the quality of that sleep. There are a number of practical reasons for this, but the consequences are pretty significant. Since we don't have a scientific baseline for how a mattress (or any other surface) affects sleep, pretty much every other sleep study ought to have an asterisk next to it. Without knowing what impact a mattress has, how can we really measure all the other complicated, intersecting factors that can affect our fragile sleep cycles?
One reason for the lack of research is cost. Imagine trying to conduct a study comparing just two different mattresses. To get a useful sample size, you'd need to dole out something like 250 mattresses to one group and 250 different mattresses to another group, and mattresses aren't cheap.
While high costs alone are not necessarily a deterrent for doing scientific study, getting funding for a mattress study can be tricky, since, as Krystal pointed out, it's largely viewed as a business problem, rather than a health one. Since research showing the health benefits of a particular mattress could improve sales for that mattress, a lot of research funding committees just steer clear of the whole question.
Instead, these studies end up getting funded by mattress companies themselves, which can lead to questionable results, according to Dr. Robert Oexman, a chiropractor and sleep researcher currently serving as the director of the Sleep to Live Institute—a research organization owned by mattress manufacturer Kingsdown.
"If you look at those studies they're typically based on just one or two mattresses, and the conclusion might be 'most people slept better on a medium-firm mattress,' but there's no definition for medium-firm," Oexman said. "That's like saying 'some subjects took a little bit of aspirin and some took a lot of aspirin.' It's not replicable and so you have to just throw that study out."
One study, published in 2011 (funded by the Sleep to Live Institute) surveyed 128 healthy people who had no sleep disorders and had them each sleep on seven unidentified mattresses, each with a different firmness level, for one month at a time.
"There were two eye-openers for me: one was that mattress does matter, in terms of your sleep, and the other was that people differed quite a bit when it came to which mattress was best," said Krystal, one of the co-authors of the study.
In the study, a sleeper's "best" bed was determined through actigraph measurements of their sleep during the night (the less movement, the better sleep) as well as self-reports of factors like their pain and energy levels the next day, and the number of times they awoke in the night.
The researchers found that the "best" bed varied greatly between individuals—each mattress was the "best" for at least 12 percent of the participants, and no single mattress was "best" for more than 16 percent of participants. And the difference between a sleeper's "best" and "worst" mattress was statistically significant: subjects felt more rested, less pain, moved less and woke up less frequently during the night, when on the mattress best suited to them.
The difference boiled down to a few minutes for each individual, but these are all healthy, good sleepers, and it shows that even with this group, the surface on which you sleep has an impact. For individuals with insomnia, who have been shown to be more sensitive to pain, the wrong mattress may have a more significant impact.
Prior to the mattress tests, the researchers also had subjects choose which mattress they wanted to try first in a showroom-like setting. They each spent a few minutes lying on the beds and pushing on them, like when you go mattress shopping. The researchers found the subjects did not choose the mattress that ended up being their individual "best bed," suggesting our current methods for bed-buying might not be very effective.
"This is just opening the door. This is not definitive research," Krystal said. "It's obvious to anybody that if you slept on a cold rock on the ground that you won't sleep as well as if you slept on something vaguely like a mattress. It seems like it's an obvious thing, but it's never been studied."
Krystal said it's been difficult to secure funding to do further research on this topic. Even this initial study, because it was indirectly funded by a mattress company, posed some issues when it came time to get it published, he told me.
If we had a better understanding of how mattresses impacted our sleep, people could make more informed decisions about picking the best surface for their individual needs and get a better night's rest. However for certain sleep ailments, adjusting your bed isn't quite enough, points out sleep neurologist Dr. W. Christopher Winter.
"If you took 100 people with a sleep problem, my guess is that dealing with things like environment, light, temperature, noise, and bedding probably solves 25-30 percent of those problems," Winter said. "But if you have sleep apnea, and that's your problem, you can make the room as dark, quiet, and cool as you want to, it's not going to change the fact that your airway is collapsing."
So if you're having trouble sleeping, these experts had a few tips. First, make sure your bedroom is dark, quiet, and cool, and that whatever you're sleeping on supports your back. Second, if you're in the market for a new mattress, seek out one that lets you try it out for more than a minute or two on the showroom floor, if possible. Lastly, if you've done all this and you're still not sleeping well, talk to your doctor. At the end of the day, sometimes it's not the mattress. It's you.
You'll Sleep When You're Dead is Motherboard's exploration of the future of sleep. Read more stories.