Dear Furniture, This is Your Thyroid

We’ve written about thyroid many times in the past (see links at the end of this post), but a new study this spring from researchers at Harvard T.H. Chan School of Public Health is the first one to suggest that there may be a link between polybrominated diphenyl ethers (PBDEs) and increased risk of thyroid problems in post-menopausal women.

Wait! What’s a PBDE?

PBDEs are flame retardants that are used in the manufacture of furniture, beds, clothes and other consumer items. They are also known endocrine disruptors, which means they interfere with the normal function of our hormones. PBDEs mess around with estrogen levels in the body, and that has a downstream effect on the thyroid. As the Harvard T.H. Chan School of Public Health reported in their article:

PBDEs have been used as flame retardants for decades, largely in furniture, in quantities up to 20% of the weight of the product. Over time, they migrate out of the furniture into the air, settle into dust in homes, schools, offices, and the outdoors, and accumulate in people’s bodies. Previous research has shown that these chemicals accumulate in fatty tissue and interfere with hormonal functions, including interference with thyroid hormones. Because it’s known that estrogen levels regulate thyroid hormones, researchers theorized that post-menopausal women may be particularly vulnerable to PBDE-induced thyroid effects.

To test their hypothesis, the researchers used data from The National Health and Nutrition Examination Survey (NHANES).

That study began in the 1960’s and uses a combination of interviews and physical examinations to assess the health of the US population in everything from cardiovascular disease and infectious disease to environmental exposures. The scientists looked at nationally representative sample of women whose blood was taken in the 2003-2004 and had the levels of four common PBDEs measured.

What the researchers found was that the women with the highest flame retardant concentrations in their blood were far more likely than those with lower concentrations to have a thyroid problem.

If the women were post-menopausal, the chances of thyroid trouble in highly exposed women were even higher.

The study isn’t perfect–one limitation is its reliance on survey participants to accurately recall and report on any thyroid problems. Like many studies, it also doesn’t prove flame retardants cause thyroid damage, only that there appears to be an association between these two things. Another limitation is that the study was looking at the older flame retardant chemicals as the NHANES data is from 2003-04 and doesn’t report effects from newer chemicals.

What to do about it

What do you do? First, don’t panic. Almost everyone on the planet has PBDE exposure. But that doesn’t mean you shouldn’t try to reduce yours, and look closer if you feel there’s a problem. Here’s how to get started: