The real deal on dust mites

Discussions General Mattresses Questions
1

I have heard it commonly stated that closed cell memory foam or latex are the best for those with mite allergies, with latex having the added benefit of being “all natural” when it is not blended with synthetics. The reasoning behind this that is often cited is that 1) the mattress itself is inedible as a food source for mites (which eat plant fibers), and 2) the dense material does not allow the mites anywhere to live.

But then I came across this study:

Schei, M.A., Hessen, J.O., and Lund, E. House-dust mites and mattresses. Allergy. 2002; 57: 538–542

It states the following:

"Despite considerable efforts to develop anti dust mite strategies, surprisingly few studies have evaluated the allergen content in different types of mattresses in everyday use. This study investigated the presence of mite feces (an indicator of mite allergens) in foam and spring mattresses. After adjustment for relevant confounders, the risk of finding mite feces was four times higher in foam compared to spring mattresses (odds ratio 4.0, 95% confidence interval (CI) 1.1–15.1), and eight times higher for the foam mattresses without cover (OR 8.1, 95% CI 1.8–36.9)."

The study is available for free online. I looked at the details as carefully as I could, and it seemed statistically sound. Searching through Medline, I have been unable to find additional peer reviewed studies on latex, or even further data to support these findings. If anyone knows of any, please post. I realize this study is from Europe, and perhaps dust mite species differ with geography and climate, but I am trying to get past the advertising and look at the actual data.

So who is correct? Is the idea that memory foam is better for dust mite resistance simply marketing?

It makes sense in theory, but I am a fan of the scientific method. If the data does not support the hypothesis, then the hypothesis must be changed or rejected. Does anyone know of additional peer reviewed studies?

2

Also, is anyone aware of data on latex vs foam vs spring, with regards to mite allergy in the actual scientific literature?

I believe the theory with latex is that the better humidity control leads to an even more inhospitable environment for mites, who generally cannot thrive in dry environments. As with the other concepts, it sounds wonderful in theory, but if anyone is aware of supporting data, it would be sincerely appreciated.

3

Hi slartybartfast,

The issue of dust mites in a mattress and their connection to allergy symptoms is very controversial and there are no specific answers to your questions that I’m aware of.

There is some information about dust mites in post #2 here including a link to a study that indicates that even effectively reducing the exposure to dust mite allergens in a mattress by itself isn’t enough to reduce the allergy symptoms that are the real reason behind these types of questions unless it is part of a more comprehensive strategy of controlling dust mites that includes other elements as well (pillows, humidity, vacuuming, hepa filters etc).

I also believe that which type of foam or even which type of mattress components (such as an innerspring) is most resistant to dust mites misses the larger point completely which is that dust mites will tend to accumulate on mattress covers or bedding and not as much inside the mattress and that regardless of the type of mattress you have that a strategy or regular vacuuming and washing in hot water along with encasing the mattress with a dust mite resistant allergen cover is a much more effective strategy to reduce dust mite populations in a mattress than focusing on the type of foam materials or components that are in the mattress itself.

There is also more information about dust mite control and mattresses in some of the information and studies linked here and here and here as well.

Phoenix

4

Thanks for the response Phoenix. I have read the data about bedding covers in and of themselves, with respect to allergic rhinitis and asthma. I wasn’t impressed by the the lack of long term data, as well as that the studies focused on allergy covers, and not the mattress material itself. Something to think about in this context is that, from what I’ve read, although the mites may live anywhere, it’s where they excrete their feces, Derp1, that matters most (gross, I know) .

Also, as you pointed out, the studies didn’t look at intervention in the context of a more comprehensive ‘whole household’ strategy. A ‘proprietary blend’ of allergy reduction strategies if you will.

That being said, I believe there are other studies out there that have tried to do just this. I just haven’t found much objective data about the mattress material itself though, which seems to be my main sticking point.

5

Hi slartybartfast,

[quote]Also, as you pointed out, the studies didn’t look at intervention in the context of a more comprehensive ‘whole household’ strategy. A ‘proprietary blend’ of allergy reduction strategies if you will.

That being said, I believe there are other studies out there that have tried to do just this. I just haven’t found much objective data about the mattress material itself though, which seems to be my main sticking point. [/quote]

With all the conflicting and “incomplete” information that is available including studies that have conflicting or sometimes inconclusive results I would agree that a more comprehensive strategy is the best approach rather than focusing on specific “pieces” of a larger puzzle that by themselves may not be particularly meaningful or effective (such as the type of foam in a mattress).

Phoenix

6

Well, I’ve already done all the other things. But as the mattress is the largest thing inside my bedroom, I am hoping that choosing more wisely may help the cumulative effect.

7

Hi slartybartfast,

For the mattress part of your strategy I would focus much more on a mattress allergy encasement, pillow encasements, and an encasement for your foundation along with regular vacuuming of the mattress surface and washing your bedding in temperatures that are hot enough to kill the dust mites and their eggs than I would on the type of foam in the mattress which IMO based on all the reading I’ve done isn’t a particulary important part of the puzzle (although it’s a “straw man” issue that many mattress salespeople love to use to promote the mattresses they sell as soon as they know that a potential customer has significant allergies).

There is more about mattress allergy encasements in post #2 here.

Phoenix

8

Being a person that is very allergic to dust mites I’ve found encasing your box, mattress and pillows with a dust mite protector is very important. Also, carpeting traps mites, so if you have it in your bedroom, that could add to your sensitivity. Wash your sheets in hot water, also.

9

I have noticed the straw man aspect of mattress sales that you describe, which I believe the study referenced above endorses to some degree.

Thanks for the link about mattress encasings. Along with hardwood floors, anti-dust mite washing, pillows and allergy shots, each element has helped to varying degrees, but unfortunately dust mites can be tenacious.