Endocrine Disrupting Chemicals (EDCs) are chemicals that disrupt the function of the endocrine system. The endocrine system performs a variety of important tasks, including regulating metabolism and reproductive functions including puberty. The most common way people are exposed to endocrine disrupting chemicals is through plastic consumer products, cosmetic products, and pre-packaged foods. Exposure to these chemicals disrupts the endocrine system, and researchers believe that exposure to these chemicals in adolescence may result in precocious (early) or delayed puberty.
Precocious puberty has a variety of consequences. One of the more mild ones is shorter adult stature. Since puberty ends significantly earlier, that means that growth will also stop significantly earlier, resulting in a shorter final height. On a more serious level, precocious puberty often leads to a variety of psychological problems later in life, especially since adolescence is not a time in which one wants to stand out among their peers. Boys with precocious puberty have often been observed to have higher risks of anxiety, depression, and substance use. For girls, a very clear link had been drawn with precocious puberty and depression as well as eating, behavioral, and substance use disorders.
Phthalates
Phthalates are a type of chemical which are used to increase the durability of plastics. They are found in hundreds of products, from food to personal care and cosmetic products. Exposure to phthalates usually occurs orally (such as eating a food that was wrapped in plastic), through skin contact, or through inhalation of microplastics in the air.
It has been well established that exposure to phthalates alters the timing of puberty in animals, but the results in humans are more unclear. A study done in Puerto Rico found that girls who were exposed to more phthalates than their peers often presented with premature breast development. However, studies conducted on young girls in the United States and Denmark found that breast development was not delayed, but the growth of pubic hair was delayed. A study done in China found that higher exposure to phthalates resulted in delayed growth and puberty in boys. Results in the variety of studies performed have been inconsistent, but generally show impact of some kind.
BPA
Bisphenol A is a chemical that is commonly used to manufacture plastics. Exposure often occurs through consumption of prepackaged food and drink. It is known to imitate estrogen (a sex hormone) in the body, therefore wreaking havoc on the endocrine system. Some studies have shown that BPA results in precocious puberty, while others show it does not. However, it is worth noting that BPA is associated with obesity.
Obesity is caused by leptin resistance. Leptin is the hormone that indicates to our brain that we are full. As people gain weight, their levels of leptin rise due to overeating. However, their bodies become insensitive to leptin over time, so very high leptin levels do not lower the appetite of someone who has obesity. People with obesity have very high levels of leptin. High leptin levels are also associated with precocious puberty, as leptin triggers the hormones that start pubertal development. Therefore, BPA may have an indirect correlation with precocious puberty by causing obesity, which results in imbalance hormones that cause early onset of puberty.
Parabens
Parabens are preservatives that are commonly used in cosmetic products. Like BPA, it also has estrogenic properties. A study conducted by University of California Berkeley found parabens to be significantly associated with earlier puberty in girls across all indicators (first menstruation, pubic hair, breast development.) It did also find associations in boys, but the correlation was less significant. Many companies, most notably Bath & Body Works, have been criticized for the use of parabens in their products.
Triclosan
Triclosan is an antifungal and antibacterial agent used in a variety of consumer products, such as soaps, toothpaste, and even toys. Like the previous chemicals, it also has an estrogenic effect, and disrupts the secretion of the hormones that result in pubertal development. The same study at UC Berkeley found little association between triclosan and breast/pubic hair development, but found a substantial association between pre-natal triclosan exposure and earlier start of menstruation. Other studies found that exposure to triclosan around the onset of puberty was also associated with early puberty. In 2016, the FDA banned the marketing of personal care products containing triclosan. Additionally, Triclosan was banned from all hygiene products in the EU in 2017.
Conclusion
As more research is conducted, it is becoming clear that the chemicals found in the products we use and consume daily are harming our endocrine systems. Many groups are advocating for bans of endocrine disrupting chemicals, especially considering the effect they have on children and fetuses. The EDC-FREE Europe coalition is a coalition of over 70 groups which are advocating for bans on these harmful chemicals.
Further Reading
Assessed and Endorsed by the MedReport Medical Review Board