Changes to organ function can sometimes alter health in detrimental ways. Often, the chemicals that we encounter in everyday products can affect our organs, without us even realizing. A prime example is perfluorinated chemicals (PFC), which are used to make fire extinguishers, carpets, fabrics, cosmetics, industrial lubricants, detergents, and cosmetics. PFCs tend to take a long time to break down in the body, and as a result, their extended stay can cause serious health issues.

In a new study of 672 men and 509 women, researchers have found a link between PFC exposure and poor thyroid function. Of the people studied, 23 people developed hypothyroidism while nine developed hyperthyroidism. Of these two groups, more women developed hyperthyroidism while more men developed hypothyroidism.

The thyroid is a gland found at the front of the neck, and it controls energy usage in the body. The gland is stimulated by the release of signals from the brain, which the thyroid analyzes and relays to the rest of the body regarding energy use. The thyroid relays brain signals by sending out its own signals. Thyroid health issues tend to alter the way the thyroid relays its signals. In the case of hypothyroidism, the thyroid does not make enough of its signals to send to the body. As a result, people with hypothyroidism begin to gain weight, are easily fatigued, and have slower heartbeats - simply becasue adequate energy is not being used. In the case of hyperthyroidism, the thyroid sends too many of its signals to the body. As a result of this issue, patients with this disorder tend to lose much weight, show muscle weakness, and have irregular or exceptionally rapid heartbeats becasue too much energy is being used. In both cases, the thyroid may begin to swell and worsen health as it deforms the patient's neck, causing what is called a goiter.

In the study, each person was asked about family history of thyroid diseases, habits, alcohol consumption, smoking, and eating. Each participant was also given a blood test to measure PFC levels as well as thyroid function. The researchers found that PFCs remained in men's blood 70 times longer than in women's. What's more, of the 23 people who suffered hypothyroidism as a result of PFC exposure, 15 of them were men. Also of note, six out of the nine people who developed hyperthyroidism were women. This is likely to be explained by PFC's shorter lifespan in women. If PFCs do not stay in the blood as long as it does for men, it doesn't not completely hinder thyroid function.

"Our study is the first to link PFC levels in the blood with changes in thyroid function using a nationally representative survey of American adults," explained study author Chien-Yu Lin, M.D., Ph.D.

However, these findings are still a little limited. Researchers were unable to identify any causation between the PFC levels and changes to the thyroid - meaning they do not know how the thyroid was changed by PFc exposure; they just know that the existence of PFC in the body appears to have altered thyroid health. Similarly, medications that the participants may have been on for thyroid issues were not noted. Those medications may have helped some of them avoid thyroid diseases. And lastly, the blood tests were only done once, meaning that PFC exposure could have changed and, therefore, changed thyroid health later, but this information was not included in the study.

Source: Wen L, Lin, L, Su T, Chen P, Lin C. Association between Serum Perfluorinated Chemicals and Thyroid Function in U.S. Adults: the National Health and Nutrition Examination Survey 2007-2010. Journal of Clinical Endocrinology & Metabolism. 2013.