
The Link Between Endocrine-Disrupting Chemicals and Early Puberty
What is the Endocrine System (Hormone System)?
The endocrine system is the name given to the system consisting of organs and glands that produce hormones and secrete them into the blood.
What is the Endocrine (Hormone System) and What Does It Do?
The endocrine glands (endocrine glands) are responsible for producing, storing and secreting hormones, each of which has different functions. These glands and the hormones they secrete mix with the blood and stimulate various organs. In this way, they perform many vital functions such as growth and development, metabolism, reproduction, and homeostasis, that is, the internal balance of the body. The main function of this system is to regulate body functions.
What are the Parts of the Endocrine System (Hormone System)?
The endocrine system consists of the hypothalamus, pineal gland, pituitary gland, thyroid gland, parathyroid gland, thymus gland, adrenal glands and pancreas, testicles in males, ovaries in females and placenta during pregnancy.
What is an Endocrine (Hormone System) Disorder?
Endocrine diseases occur when there is a deficiency or excess of hormones secreted by the endocrine glands, when the endocrine glands are too small or too large, or when the hormones do not work properly. In this case, the hormones disrupt the regulatory functions they are supposed to perform. Diabetes, thyroid deficiency, Cushing's syndrome are examples of diseases caused by disruptions in the hormonal system.
What Causes Endocrine (Hormone System) Disorder?
Disorders in the hormonal system can cause secondary attention deficit, immune system problems, metabolic disorders, premature birth, early puberty or gynecomastia, and epigenetic differences in the urogenital system. In addition, developmental disorders, polycystic ovary, hair growth, erection problems, beardlessness, small testicles and penis, inability to gain weight, inability to lose weight, obesity, hair loss and many similar problems are also caused by disruptions in the endocrine system.
Endocrine (Hormone System) Disrupting Chemicals
Endocrine disrupting chemicals are foreign substances that are suspected to cause hormonal system disorders, both naturally occurring and synthetic.[1] These chemicals interact with nuclear receptors in undesirable ways, disrupting the synthesis, transport, mechanisms, and metabolism of hormones. Although not limited to these, it has been observed that α and β estrogen receptors, androgen receptor, pregnane X receptor, peroxisome proliferative activating receptor α and γ, and α and β thyroid receptors are particularly affected by endocrine disrupting chemicals. Chemicals that affect different mechanisms are associated with developmental defects, immune, reproductive, and nervous system dysfunction, and increased risk of cancer. Type 1 diabetes, obesity, and nonalcoholic fatty liver disease are also among the diseases caused by endocrine disruptors.
The idea that some chemicals could cause diseases and disorders in the endocrine system was first put forward in 1997 in the book Our Stolen Future, which claimed that DDT, dioxin, DES, and many other industrial chemicals damaged the endocrine system and caused disorders in the reproductive system.[1] At the time, the general consensus was that these chemicals showed their effects in high doses and were rare. Now, although more than 1,000 chemicals are identified as endocrine disruptors, this number is not even close to the truth. Even today, the methods used to identify and discover these chemicals are not systematic and fail to report the potential dangers of endocrine disrupting chemicals.

Endocrine Disruptor Products
Endocrine disrupting chemicals have become intertwined with our daily lives after industrialization, especially in cosmetic products, food packaging, pesticides and textile products. Although there are restrictions on some endocrine disruptors, especially those that emerge as by-products or mix with soil, water and air still pose a completely unpredictable danger. Endocrine disrupting chemicals that mix with nature threaten not only human health but also the ecosystem. These chemicals, which have found a place in the formulas of cosmetic preparations, are frequently used as preservatives, antibacterials and UV filters within the framework of restrictions. Some were completely banned after the Stockholm Congress, but they are still in use worldwide.
Endocrine Disrupting Chemicals
Bisphenol A is one of the most common endocrine disruptors in cosmetic products. Although there are many studies proving that it affects the endocrine system and is associated with cancer, it is frequently used in plastic production and, as a result, in packaging. It easily penetrates the food or cosmetic product inside the packaging material and enters the human body. BPA, a synthetic estrogen, has a receptor affinity of 1000 to 10,000 times that of natural estrogens. It negatively affects primarily the female reproductive system, as well as the pancreas, immune system and central nervous system.[31]
Dichlorodiphenyldichloroethylene (DDE) is a derivative of DDT. It causes developmental disorders and male reproductive system disorders. It is very difficult to remove from the body because it accumulates in fat tissue. DDT and DDE are substances used in insecticides. It is also one of the first substances to have endocrine disrupting properties discovered.[1], [10]
Triclosan is an endocrine disruptor often added to cosmetics as a preservative. It is found in shampoos and soaps.
Dioxins are endocrine disruptors that are produced as a by-product of industrial production. They are released into the air due to the burning of waste. [10]
Phthalates are added to many personal care products to increase fluidity. During pregnancy, they can inhibit or damage fetal development and cause premature birth. [9], [29]
The endocrine disruptors in our daily lives are not limited to these; many endocrine disrupting chemicals are added to product formulations for different purposes.
What is Early Puberty?
Early puberty is a pathological condition characterized by the early manifestation of secondary sex characteristics. This condition is observed in one in every 5,000 to 10,000 children. This condition, which is up to ten times more common in girls than in boys, manifests itself in girls with early breast development before the age of 8 or menstruation before the age of 10, and in boys with secondary sex characteristics appearing before the age of 9. Early puberty causes an increase in hormone secretion in children, which can have consequences that threaten both their physical and psychological health. While a cause cannot generally be determined in girls, a specific cause is more likely to be found in boys.
Precocious puberty is divided into two according to its dependence on the gonadotropin hormone; the one related to the gonadotropin hormone is called central precocious puberty, and the one unrelated is called peripheral (pseudo-precocious) puberty. The most common central precocious puberty is the idiopathic form.
What are the symptoms of early puberty?
In girls, breast growth, underarm and groin hair, acne, sweat odor, penis or testicular growth are signs of early puberty. In other words, the early changes that a child should experience during puberty are signs of early puberty.
What Causes Early Puberty?
Early puberty causes the pineal glands to fuse early and, as a result, development to be completed early. Tumors in the nervous system, hematoma formation in the hypothalamus, adenoma formation in the pituitary gland, short stature in adulthood, breast or reproductive system cancers have been associated with early puberty. Again, it can have consequences such as hypertension, diabetes and obesity in adulthood.

Does Endocrine Disorder Cause Early Puberty?
Adolescence is a period initiated and regulated by sex hormones. Therefore, disorders in sex hormones will also affect the puberty process.
Although puberty is a condition that begins and develops depending on many genetic factors, the effect of environmental factors on development cannot be denied. Especially central precocious puberty, since it is dependent on the gonadotropin hormone, can be triggered by endocrine disrupting chemicals. Kisspeptin neurons, which are responsible for activating GnRH neurons in the neuroendocrine regulation of puberty, are sensitive to endocrine disrupting chemicals.[7], [8] It has been observed in mice that these neurons are damaged as a result of exposure to Bisphenol A, an endocrine disruptor. Again, in studies conducted on mice, it was observed that the ovaries of mice exposed to Bisphenol A and Diethylhexyl Phthalate during the fetal period were smaller than normal.[35] When rodents were exposed to endocrine disrupting chemicals during puberty, early puberty or delayed puberty occurred. It was determined that exposure to dibutyl phthalate during puberty accelerated puberty and disrupted estrogen balance in mice.[30] Bisphenol A has been observed to accelerate the onset of puberty by directly affecting neural pathways and reducing the activity of GnRH neurons.[18]
Many endocrine disrupting chemicals have also been observed to cause early puberty in humans. For example, phthalates accumulate in breast tissue and cause changes in this tissue. Perfluorooctanoic Acid changes the structure of the mammary gland, again causing the tissue to grow. Dichlorodiphenyltrichloroethane, known as DDT, and its metabolites are linked to early puberty due to their estrogenic and anti-androgenic activities. In light of this information, it can be concluded that endocrine disrupting chemicals - regardless of the time and route of exposure before puberty - are effective in the pathophysiology of early puberty.
Ways to Prevent Early Puberty
Studies show that early puberty is closely related to genetic factors. In addition, exercise, diet, consumption of foods containing preservatives and dyes, and pollution of the living environment are among the risk factors.[5], [9], [12], [15], [34] While it has been observed that the risk of early puberty decreases as vegetable and protein consumption increases, it has been observed that excessive animal food intake increases this risk.[12], [15] It is possible to reduce the risk of early puberty with proper nutrition, sufficient exercise, healthy sleep, and extra care in the consumption of cosmetics , personal care products, and food.
Source
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