Have you ever picked up an item at your local grocery store and wondered how the expiration date could be so far into the future? You’ve probably wondered a few times whether those preservatives could inflict significant damage upon your health.
Previous studies testing the effects of chemicals found in common foods and household items have established that they are dangerous.
These chemicals are called endocrine disruptors, and in contrast to the usual linear dose-response of some chemicals, these endocrine disruptors actually have a U- or inverted U-shaped dose-response curve. This means that exposure to low levels of these chemicals could actually be more potent than higher levels of exposure.
Despite the amount of evidence from studies of endocrine disruptors on animals, scientists have had a difficult time replicating the tests on human subjects since it poses several ethical issues.
A recent study from researchers at the Cedars-Sinai Medical Center, published in the Nature Communications journal, demonstrated a method of stem-cell testing that allows for experimentation on humans involving the preservative chemicals of endocrine disruptors.
Three specific endocrine disruptor chemicals were analyzed in this experiment due to their abundant presence in our daily lives.
Butylhydroxytoluene (BHT) is an antioxidant whose primary function is to preserve nutrients as well as fats. Perfluorooctanoic acid (PFOA) is a polymer found in the carpets and cookware of many homes. Tributyltin (TBT) is a compound present in paint and has the ability to infect seafood if it ends up in water.
In order to test these three chemicals, human stem cells were used to make hormone-producing tissues. The manufactured tissues were then chronically exposed to the chemicals. The researchers wanted to determine if the exposure contributed to obesity by interrupting the signals sent to the brain from the digestive system.
Dhruv Sareen, assistant professor of biomedical sciences at the University of California, Los Angeles and the director of the Induced Pluripotent Stem Cell Core at the Cedars-Sinai Board of Governors Regenerative Medicine Institute, and his team of researchers converted the cells from adult blood samples into pluripotent stem cells, which behave like embryonic stem cells and are capable of developing into any cell type.
The stem cells were then used to grow epithelium tissue to mimic the lining of the gut and neuronal tissues to mimic the brain’s hypothalamus region, which controls appetite and metabolism in the human body.
BHT, PFOA and TBT, were administered to the cells independently and in unison. The researchers that the chemicals rendered signalling hormones ineffective, while also damaging mitochondria, which in turn affected the body’s metabolism.
The majority of the damage inflicted by these chemicals occurred in the early stages of the development of a hormone system, so Sareen concluded that there is potential for the harmful effects to impact pregnant women and their fetuses.
“We discovered that each of these chemicals damaged hormones that communicate between the gut and the brain,” Sareen said, according to ScienceDaily. “When we tested the three together, the combined stress was more robust.”
Obesity is quite a prominent problem in the United States. According to federal statistics, more than a third of American adults fit into the obese category, and it is a leading cause of death.
“This is a landmark study that substantially improves our understanding of how endocrine disruptors may damage human hormonal systems and contribute to the obesity epidemic in the U.S,” Clive Svendsen, the Kerry and Simone Vickar Family Foundation Distinguished Chair in Regenerative Medicine, said, according to ScienceDaily.
