Could Mattress Flame Retardants Affect Thyroid Function?


I’ve become, rather reluctantly, an activist. Physicians are notoriously apolitical and decidedly not activist material, but after reviewing the data on flame retardants and how clearly their harm to our thyroids has been documented, GAME ON!

Perhaps you're thinking: “That nutty organic gynecologist – it’s not like I’m wearing kid pajamas. Why is she bothering me with flame retardants?”

Think again, my friends. Turns out that your mattress may be your most likely culprit. Unless you're rockin’ an organic mattress, yours is chock full of these nasties.

Flame retardants are put in just about anything that may burn: car upholstery, hospital gowns and curtains, IV pumps, airplane seats, plastic casings around TVs. They save hundreds of lives in the US each year. However, flame retardants end up where they should not be: inside your body via the skin. Are the benefits worth the widespread risk?

I’ve become fascinated with the 700+ known endocrine disruptors to which we get exposed daily and routinely. While preparing for a talk on how our conventionally-made toxic clothes may muck with our hormones, fertility, neurological wellness, and risk of cancer, I was most impressed with the volume of data concerning flame retardants.

A subset of the flame retardants known as BFRs (as in Brominated Flame Retardants) are most likely to bioaccumulate and cause adverse health problems, particularly in kids. Breast milk of women in the US have the highest concentration of BFRs in the world.

Here Comes Thyroid

The most sensitive toxic endpoint of BFRs is thyroid function. Here’s how:

1. Most BFRs lower thyroid hormone levels

2. Some (PCBs) interfere with thyroid gene transcription

3. They bind to the thyroid receptor and often block it

4. BFRs can bind to thyroid transport proteins with varying affinities

5. In mice, BFRs have been shown to increase liver and thyroid cancer

6. One human study from Sweden showed an increased risk of non-Hodgkins lymphoma associated in a dose-dependent manner with one particular flame retardant called BDE-47. The study was small and did not reach statistical significance, but clearly we need more research.

I find the various ways in which flame retardants may harm us to be, well, terrifying.

What gives me solace is the Precautionary Principle, which states: If an action or policy has a suspected risk of causing harm to the public or to the environment, in the absence of scientific consensus that the action or policy is harmful, the burden of proof that it is not harmful falls on those taking the action.

In other words, let’s stop sleeping on toxic flame retardants, even though the data does not yet show an undisputed link to thyroid problems, and get our organic mattresses on! That’s step 1.

Now, back to my journey of toxic self-discovery. Join me at to hear about my “Wear Organic” challenge beginning January 1, 2011. For more details, go to (Environmental Workng Group’s list of data on flame retardants is exceptionally rigorous).

Written by Dr. Gottfried–

Gottfried Center for Integrative Medicine

Sara Gottfried, MD

300 Lakeside Dr, Suite 202

Oakland, CA 94612



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