There is much been thrown around on the internet these days about how you should eat for thyroid health. This post is not so much about the food as about how NOT to prepare foods namely cooking with Teflon and newer nonstick pans.
Way back in 1975, Full and Parkins reported in the Journal of Dental Research that boiling water in teflon plans produced a “pronounced increase” in fluoride levels. An excerpt from this study is reproduced below. Teflon is made from fluorinated chemical =Polytetrafluoroethylene (PTFE), and thus the relationship between Teflon use and fluoride contamination of food is plausible.
Here are a few excerpts from the Full and Parkins study:
“The fluoride concentrations observed before and after boiling for each container and the change in fluoride concentrations are shown ... A pronounced increase was seen with the Teflon-coated vessel. The boiled water from the aluminum vessel showed notable decrease. Little change was noted in the fluoride concentration of the water boiled in the stainless steel and Pyrex vessels. The amount of water remaining in each vessel was estimated; in the aluminum, stainless steel, and Pyrex vessels water was reduced by a third and in Teflon by a half. . . .
The variation of fluoride content in foods prepared in cooking vessels of different compositions should be studied. The magnitude of the composition effects seen with the aluminum and steel containers suggests that significant alterations in fluoride uptake into boiled foods may occur.”
Despite the potential significance of these findings to the fluoride exposures of millions of Americans, there has been virtually no careful attempt in the subsequent 40 plus years to replicate the findings.
In 2010 there was a study that showed that the chemical compound PFOA, which is found throughout the home in products like fast-food packaging, and flame/stain-resistant coatings - and of course Teflon coated pans may be linked to Thyroid disease.
This study showed that those with higher levels of PFOA in their blood have higher rates of thyroid disease. The study also implied that women (who are more susceptible to thyroid problems) are at double the risk!
Personally I dislike Teflon and I'm not afraid of cooking with fat. Fats are crucial for healthy hormone function but that does not mean you need to use tons of them and cook them at high heat. And, please just stay away from those nasty industrial seed oils.
SOURCE: Full CA, Parkins FM. (1975). Effect of cooking vessel composition on fluoride. Journal of Dental Research 54: 192.
Dr. Jerome Craig, DC