Environmental Exposures and Men’s Hormone Health

We live in a chemical-filled world. Many of these chemicals are endocrine system disruptors, meaning they mess with how our hormonal system works. Almost everything we encounter on a day-to-day basis is full of chemicals that may interfere with proper hormone function. For men, endocrine disruptors may reduce testosterone levels and may be contributing to a population-wide decrease in testosterone over the past 40 years. 

Phthalates

Phthalates are chemicals added to plastics to make them softer or more flexible, like in shower curtains, vinyl coverings, or food packaging. Oily or fatty foods exposed to phthalates in packaging (like commercial plastic wrap) or foods heated in these packaging materials seem to be at increased risk of leaching. These chemicals are often added to personal care products like moisturizers, shampoos, or body wash as “fragrance.” Phthalates are also present in pesticides, medical equipment, insect repellent and plastic toys.

Phthalates are known hormone disruptors. Research is still limited but one Chinese study found a relationship between phthalate exposure and testosterone. In this study, 90% of participants had measurable levels of phthalates in their blood and participants with the highest levels of phthalates had lower testosterone. The association was most noticeable in boys, ages 6-12, and men, ages 40-60.

Choosing organic produce can reduce exposure to pesticide residues.

Choosing organic produce can reduce exposure to pesticide residues.

Pesticides

Chronic exposure to pesticides has been linked to decreased serum testosterone levels in men. One study of Native American men found that higher levels of chlorinated pesticides were associated with lower levels of testosterone. Another small study in Thailand focused on occupational exposures in farmers found similar results. Chlorinated pesticides have also been associated with disruption of proper thyroid and female hormonal function. Occupational pesticide exposure has been linked to increased risk of certain cancers and neurological disorders.

Pesticide exposure is unavoidable in our world. DDT, a well known chlorinated pesticide, has not been used in the US for decades but continues to hang out in the food system. We are also exposed to pesticides every day when we eat non-organic produce or processed foods.

While these studies do not show a link between eating non-organic produce and lower testosterone levels, choosing organic products for pesticide-heavy fruits and vegetables can reduce overall pesticide exposure. 

Bisphenol A

Bisphenol A (BPA), another chemical commonly found in plastic products, may negatively impact testosterone and sperm levels. BPA may interact with the cells that produce testosterone in the testicles, as well as interacting with the pituitary gland, the “master gland” of the endocrine system. Increased BPA levels have been associated with lower testosterone levels in adolescent boys and elevated testosterone in adolescent girls. Additionally, BPA has been shown to reduce sperm count and quality in animal models.

BPA is found in some older water bottles, food containers, thermal receipt paper, aluminum can linings, and hundreds of other products.

Reducing exposure to BPA by choosing products that are BPA free or better yet, are not made of plastic is a way to keep your hormone function healthy. Taking small steps like choosing glass or metal containers instead of plastic can have a big impact on your overall exposure to these chemicals.

Parabens

Personal care and skincare products are common sources of endocrine disrupting chemical exposure.

Personal care and skincare products are common sources of endocrine disrupting chemical exposure.

Parabens are a class of chemical preservatives that have been used in skin and hair care products since the early twentieth century. Several parabens are banned in Europe but there is no regulation on their use in the United States.

Parabens have been extensively studied and have been promoted as safe for human use. Recently, however, more research has focused on the hormonal impact of parabens. Some research suggests that parabens act like estrogen in the body and may interfere with proper estrogen metabolism. There is even some preliminary research suggesting that paraben exposure may be involved in the development of breast cancer.

To me, the jury is still out on the overall health effects of parabens. Much of the research has been done in the lab instead of in human subjects, meaning that the effects in the body may not be the same as those observed in the lab. Given the potential for hormone disruption, I still think reducing paraben exposure is a good idea. I make sure my skin care products are paraben-free because even if the research has a way to go, less chemical exposure can’t hurt.⠀⠀⠀⠀⠀⠀

Conclusion

Because we live in a chemical-filled world, it is impossible to completely avoid these chemicals. But you can reduce your exposure by choosing personal care products, foods, and containers that are free from endocrine disrupting chemicals. The Environmental Working Group is a great resource for reducing your exposure to potentially harmful chemicals. Their website, yearly Dirty Dozen and Clean Fifteen produce lists, and Healthy Living app are free and easy to use.

References

  1. Engeli RT, Rohrer SR, Vuorinen A, Herdlinger S, Kaserer T, Leugger S, Schuster D, Odermatt A. Interference of Paraben Compounds with Estrogen Metabolism by Inhibition of 17β-Hydroxysteroid Dehydrogenases. Int J Mol Sci. 2017 Sep 19;18(9):2007.

  2. Goncharov A, Rej R, Negoita S, Schymura M, Santiago-Rivera A, Morse G; Akwesasne Task Force on the Environment, Carpenter DO. Lower serum testosterone associated with elevated polychlorinated biphenyl concentrations in Native American men. Environ Health Perspect. 2009 Sep;117(9):1454-60.

  3. Pan G, Hanaoka T, Yoshimura M, Zhang S, Wang P, Tsukino H, Inoue K, Nakazawa H, Tsugane S, Takahashi K. Decreased serum free testosterone in workers exposed to high levels of di-n-butyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP): a cross-sectional study in China. Environ Health Perspect. 2006 Nov;114(11):1643-8.

  4. Panuwet P, Ladva C, Barr DB, Prapamontol T, Meeker JD, D'Souza PE, Maldonado H, Ryan PB, Robson MG. Investigation of associations between exposures to pesticides and testosterone levels in Thai farmers. Arch Environ Occup Health. 2018 Jul 4;73(4):205-218.

  5. Scinicariello F, Buser MC. Serum Testosterone Concentrations and Urinary Bisphenol A, Benzophenone-3, Triclosan, and Paraben Levels in Male and Female Children and Adolescents: NHANES 2011-2012. Environ Health Perspect. 2016 Dec;124(12):1898-1904.

Joshua Corn