Fluoride is one of the most common environmental contaminants, particularly in water. Fluoride contamination is of greatest concern in poorer regions where the water quality tends to be substantially lower than it is in middle-income regions. It is also known that children tend to be much more sensitive to fluoride exposure, so the impacts of fluoride are particularly evident during early childhood development. Fluoride is a key ingredient in toothpaste, as it is known to fortify enamel and bind together hard tissues such as teeth. However, no matter how much your dentist loves fluoride toothpaste, it is also known to result in significant changes to the function of the endocrine system.
The endocrine system has a wide variety of responsibilities, including balancing hormones for reproductive and digestive processes. This means that the endocrine system is responsible for menstruation, fetal development, digestion, blood sugar levels, among many others. It is also responsible for guiding development, especially that which occurs during puberty. These processes are essential to maintaining health, and fluoride has been shown to affect the endocrine system substantially. Some of the primary parts of the endocrine system include the nervous system, the reproductive system, the thyroid and parathyroid, the adrenal glands, and the pancreas.
The nervous system is our body’s communication network that allows our brain to send messages to our body, such as signals to move, and for our body to send messages to our brain (such as pain and needs like hunger.) Fluoride has been shown to have impacts on the nervous system that result in the impairment of sleep, memory, and concentration. Fluoride and loss of sleep have both been correlated with the acceleration of degenerative neurological disorders such as Alzheimer's.
In laboratory experiments on female rats, fluoride has been shown to cause structural tissue damage to the uterus and ovaries, resulting in a decreased weight in the organs. Another observed result was lowered levels of Gonadotropin-Releasing Hormone (GnRH), a hormone that regulates the production of the hormones responsible for ovulation and the development of ovaries. This means that fluoride exposure may cause abnormal ovulation and infertility.
Fluoride exposure did not affect the GnRH or the hormones responsible for sperm production and testicular maturation. However, there was a substantial decrease in testosterone levels which impaired the fertility of the male rats.
The lack of balance of these hormones results in irregular or abnormal patterns of menstruation and pubertal development as well as infertility. Additionally, these hormonal abnormalities resulted in lower body weight of offspring in experiments. While more study is necessary, connections between these hormonal imbalances have been associated with an abnormally early onset of puberty.
The thyroid is an organ located just under the Adam’s Apple which produces hormones to regulate metabolism, growth, and development. Fluoride exposure has been shown to inhibit the growth of the thyroid and result in dysfunctional hormone production. This dysfunction results in reproductive dysfunction and lower metabolic rate. A lowered metabolic rate results in weight gain and also inhibits the body’s ability to absorb vitamins + minerals in the digestive tract.
The parathyroid, the lower portion of the thyroid which regulates calcium levels in the blood, is also affected by fluoride exposure. Fluoride has been observed to cause an enlarged and therefore overactive parathyroid. In laboratory experiments on rabbits, this has been observed to result in faster degeneration of the parathyroid. All of this has been shown to result in osteoporosis, a condition in which the bones become less dense and more brittle, therefore breaking more easily.
Excess fluoride exposure has also been observed to cause dysfunction in the pancreas. In the short term, exposure to fluoride has been shown to result in a fall in insulin levels, which raises blood sugar. Long-term exposure to fluoride has been shown to result in inhibited insulin secretion and reduced insulin sensitivity. This ultimately results in impaired glucose tolerance, also known as prediabetes.
While the impact of fluoride on human adrenal glands is less clear, the function of the adrenal glands of rats was substantially impacted by fluoride exposure. Adrenal glands are responsible for the secretion of steroid hormones, including those responsible for reproductive processes. Some experiments have shown no effect, while others have shown a fivefold increase in hormones such as epinephrine, the hormone responsible for the “fight or flight” response. The weight of the adrenal gland also was observed to have increased, and the production of sex steroids (testosterone, estrogen) was inhibited. The consequences of these results are unclear.
The above results of fluoride on the endocrine system have substantial results on overall health. Some of the most severe consequences of fluoride exposure include neurological degeneration, menstrual irregularity, infertility, and osteoporosis. These impacts are particularly concerning in low-income regions, where fluoride exposure is more common due to generally lower water quality. The effects of fluoride can be mitigated by reducing exposure, as the impacts of fluoride exposure often occur in the short term and can be reduced within hours of reduced exposure. Exposure can be reduced most easily by using a water filter.
Sources:
https://www.sciencedirect.com/science/article/pii/S0045653520317604?via%3Dihub Assessed and Endorsed by the MedReport Medical Review Board