Parabens are synthetic preservatives used in foods, pharmaceuticals, cosmetics and personal care products such as deodorants, moisturizers and shampoos. Common parabens include methylparaben, ethylparaben, propylparaben and butylparaben. Parabens allow skin care products to survive for months or even years in your medicine cabinet; however, they also enter your body through your skin when you use these products. According to Mercola.com, the body can absorb as much as five pounds of cosmetic chemicals every year. Parabens can mimic hormones in the body and disrupt functions of the endocrine system.
Colby College's Clean Makeup website reports that parabens can mimic estrogen and disrupt the body's hormone system. Cornell University reports that a high lifelong exposure to estrogen can increase breast cancer risk. Estrogen, and synthetic chemicals that act like estrogen, play a role in stimulating the division of breast cells and affect other hormones that stimulate breast cell division. Your body does not easily break down synthetic estrogen, and it can accumulate in fat cells, including breast tissue. In 2004, a study by the University of Reading in the United Kingdom found concentrations of parabens, particularly methylparaben, in human breast tumors. The study examined only the presence of parabens in the tumors but did not determine that they were the cause of the tumors.
The ability of parabens to mimic other hormones makes them endocrine disruptors, substances that adversely affect the endocrine system. The endocrine system releases hormones into the bloodstream and is involved in a number of functions related to reproduction, waste elimination, digestion and metabolism. Endocrine disruptors such as parabens can lead to early puberty in adolescent girls and boys, as reported by the New York Times. Endocrinologists have observed the average age of puberty decreasing in the past several decades and have seen girls as young as eight exhibit breast development and pubic hair growth. Endocrine disrupters can also lead to testicular enlargement and breast development in young boys.
Decreased Sperm Levels
Parabens can also adversely affect the male reproductive system. In a study by the Tokyo Metropolitan Research Laboratory of Public Health, researchers administered parabens to three-week-old rats. After four weeks, researchers examined the rats and found their sperm production significantly decreased in relation to the amount of parabens they had received. The rats who received the highest dose of parabens, which was consistent with the daily acceptable intake of parabens in Europe and Japan, showed a significant decrease in sperm concentration.