The bottom line
This is a tough one to evalute. Some people feel better with stiff mattresses, some feel better with memory foam. But while memory foam used to be really expensive, prices are much more reasonable now.
The importance is easy to understand: you sleep roughly a third of your life, so the mattress you choose can majorly impact pain. Any time you pay more attention to ways to optimize sleep, you increase the chances of a pay-off. We didn’t score memory foam based off of health risks, as they are largely uncertain. Rather, the almost cliche-sounding “space age conforming foam” really does conform to your body, and may help you get a better night of rest. And that’s really important for pain. Will it keep you in one position for too long? Will it help you be more comfortable when you wake up? That’s highly dependant on one person: you.
Does the science make sense?
Memory foam did indeed come from NASA, so it’s literally “space age technology”. Astronauts are subject to crazy amounts of g-force when they lift off, so it’s of utmost importance for NASA to prevent discomfort. And we as pain patients also are looking for any way to prevent discomfort … see the connection?
You don’t want things jabbing into your back, and conversely you don’t want a big dip where a body part will sag into. NASA discovered in the 1970s that a type of material called “viscoelastic” foam would conform to shapes, especially warm shapes like a human. Visco referes to the property of viscousness, flowing like honey. And elastic means it can stretch without breaking. The key to this viscoelastic memory foam is that it can stretch/flow into a shape that conforms to your shape, and then miraculously go back to flat when you get off. This can be seen in the famous “hand test” at mattress stores, where you can leave a temporary handprint in a memory foam mattress.
A Swedish foam company translated this technology to the world of beds in the 1980s, and voila the Tempur-pedic mattress was born! So while many companies exist now (albeit with source material coming from a few select factories), Tempur-pedic was the original, and also the one I first saw on late night TV infomercials as a child of the 80s. Why was I up past midnight as a child? Hmmm, that’s a question for another day.
Memory foam measurements
If you’re thinking about buying memory foam, don’t just go by feel. Learn the measurements, do the research, and have fewer regrets.
All memory foam is similar in concept: take a synthetic foam made out of polyurethane, add in magic chemicals, and the foam now is denser and can flow/stretch in reponse to pressure and temperature. Now there are only two measurements that you really need to know about (the others correlate well with these two):
ILD stands for “indentation load deflection”, and basically just tells you how hard or soft a foam is. Technically, it’s defined the number of pounds of pressure you need to cause a 25% compression of a 4″ thick foam, when using 50-square-inch indentation tool. An ILD of 13-15 pounds is typical for a nice memory foam mattress. Too soft is bad for your back, as is too firm, so many foam mattresses layer soft foam for comfort on top of harder foam for support.
Density is measured in pounds per cubic foot of the foam. 3 lbs is very low, and will feel nice and soft at first but then get too soft as it ages. 5 or 6 lbs is is pretty high, and typical for high end beds.
What do trial results show?
Guess what? There’s only been one trial ever done on memory foam mattresses and pain. Craaaaaazy! Especially since many people buy these beds specifically to help with back pain. So this part of the review will be quick and painless (har har).
The lone study was done back in 2010. Researchers compared a foam and latex mattress with normal spring beds, in people that had back and shoulder pain. They found improved back pain and stiffness with the foam and latex mattresses. This also translated to fewer days of poor sleep and discomfort while sleeping.
The trial wasn’t of the highest quality though. First, the patients were all referred to the study by chiropractors (in other words, it wasn’t a random sample). More importantly, the comparison was between brand new foam/latex beds and the SAME OLD BEDS the patients had been using before. If you have back pain, it could be made worse by your old and crappy bed, so simply switching to a new high-quality bed could be of help. Another problem: the trial didn’t describe the type of foam very well. Some memory foam beds can make your back pain worse if they’re too stiff or too soft, so no one memory foam bed is king.
And a bonus study on firmness
There’s also been one trial on mattress firmness (not using memory foam) that’s cited pretty often. It found that a firm mattress (with a firmness rating of 2.3 on a scale of 1-10) was overall a bit worse for low-back pain, compared to a medium-firm mattress (at 5.6 on the scale). Does this study mean you should ditch firm mattresses? Well … no. People have different responses to bed types, and no single study using only two bed types can answer the question of bed firmness impact. But this study is still quite helpful, as it shows that you shouldn’t stick to a firm bed solely due to the belief that it will eventually help your back.
Memory foam and your joints
There is roughly a zero percent chance that springs are the best option when creating a bed for a pain patient. Springs are springy — they don’t contour to your body parts. So if you sleep on your side, a memory foam mattress will cradle your head/shoulder/hip/knee points of contact depending on the weight of those body parts. A spring mattress will not. The same line of thought applies to back sleepers and stomach sleepers as well. Some people prefer a mix of memory foam and springier latex, in order to add just a bit of resistance.
Here’s something I just can’t believe: there are no great studies on memory foam and pain mechanics. And millions upon millions of people either have memory foam mattresses or are considering getting them. There are hundreds of studies on the best angle for gym exercises, the best form for running, etc etc. So this is a call to researchers to get going on an issue that effects every single person looking for more comfortable sleep.
Again, evidence is scarce here. A big concern for some is the chemical composition of memory foam.
The cool kids (and cool parents, and cool grannies) are more and more using “natural” latex mattresses these days. Part of the reason is all the chemicals in memory foam. Although there haven’t been any good studies on the health effects of these chemicals, we do know a few things:
How long your mattress is smelly depends on the mattress you buy. Some low quality mattresses can let off fumes for up to three weeks or so, but most good mattresses take less than a week. If the smell is really bad or nauseating, hopefully you can return your mattress, but smells that strong are fairly rare.
Like always, the impact of these smells somewhat depends on who you are. Like if you have multiple chemical sensitivities or severe asthma, it might be wise to stay away from memory foam. Anybody would benefit from opening windows in the bedroom or even airing the mattress out in a garage first. Nobody knows whether or not these fumes have health impacts (at least coming from human trial evidence of memory foam beds). Anecdotally, some people get headaches and nausea from off gassing, but it’s highly variable.
One of the biggest memory foam companies, Essentia, got in trouble by the FDA for unsubstantiated claims of making “natural” memory foams. While that doesn’t mean that natural memory foams are impossible, it does mean that you shouldn’t get hypnotized by marketing hype — memory foam (almost?) always has chemicals in it, because chemicals are required to make that space-age viscoelastic foam.
This is only a dealbreaker for a small percentage of people, but is worth noting: memory foam doesn’t bounce. And when you and your partner want to bounce together, memory foam won’t let you. There’s simply no spring to it. That doesn’t at all mean you can’t do the deed, but if bouncing is important to you, consider latex instead.
There are many varieties of memory foam, plus a wide array of foam mattress toppers. Latex is memory foam’s main competition for those looking to ditch their spring mattress.
Your aging foam mattress
Just like humans lose their memory over time, so do memory foam mattresses. Again, there are no good studies on how long memory foam lasts compared to spring mattresses, but we know that high-quality memory foam can last a good 10-15 years without too much sagging. Lower quality memory foam is likely to develop a big ol’ impression of your body within a couple years.
A memory foam bed won’t age in the same way as a spring bed. The springs will still be hard metal springs twenty years later, and the cushiony material at the top will just compress down to nothing. Memory foam on the other hand will break down a bit and get softer. That’s why it’s important to consider foam density when you buy the mattress, since the warranty isn’t that likely to cover a bed getting too soft over time.
Heat and cold
Some people like the warmth of memory foam, which retains heat in its foam cells. Others get overly hot, especially if you “sleep hot” or have hot flashes. There are a few products which seem to help with air circulation, or even incorporate gels meant to cool the whole thing down a bit. Conversely, some people with pain issues sleep with an electric blanket. That can mess up the memory foam’s function (temporarily), as it responds to heat. But a thick enough layer in between the memory foam and the blanket may help. For heat purposes, it’s actually somewhat important to pick the right cover — thick wool or thin cotton, or even something else like bamboo. Lastly, keep in mind that electric blankets have mixed evidence for being associated with certain cancers, such as endometrial cancer.
What type should you get?
The most important thing: try more than one memory foam mattress at mattress showrooms! There’s no downside, and plenty of upside.
The gorilla in the room is Tempur-Pedic, who started the memory foam game and has pretty good reviews. But they’re also SUPER DUPER expensive. Tempur-pedic only has a few different mattress types, with the main (“Original”) one being eight inches thick with a three inch memory foam layer of 5.3 lb density as the top part. They also have a higher-density one with 7.0 lb density (called “Tempur-HD”), and one called the “Cloud Supreme” that has two different memory foam layers (two inches of 4 lb plus two inches of 5 lb). The purpose of that is to maintain a soft feel at the top.
If you don’t have $2000 or more laying around, all kinds of companies offer memory foam now, from Ikea to online options like Casper. If you’re risk-averse, you can try a memory foam topper, and put it on your normal bed for a while. That’ll run you between $50-$200 usually. But sticking a memory foam topper on an old spring bed won’t work very well, because the saggy part of the spring bed will still be there.
A tail of two foams: memory vs latex
My mom owns a couple latex beds, so I’ve been able to very directly compare latex to memory foam during the same period of time. Latex is much more springy, while memory foam feels like dense quicksand. Some people like one much more than the other, but you simply have to try them out.
While there are both natural and synthetic or blended latex mattresses, latex tends to be more natural than most every memory foam mattress. Latex avoids most of the chemical off-gassing of memory foam as well. A wise choice would be to try both latex and memory foam, and maybe even consider a blend of both if you like both. Some people even like their favorite spring-mattress company’s bed, with a memory foam or latex topper pre-built in. That will usually cost a ton of money though.