Mounting research has shown that exposure, especially prenatal exposure, to hormone disrupting or endocrine disrupting chemicals (EDCs), can lead to fertility issues, including Polycystic Ovarian Syndrome (PCOS) (Rutkowska 2016). The most well-known examples are phthalates, which have uniquely dangerous effects on the endocrine system.

What are phthalates?

Phthalates are synthetic chemicals that are known reproductive toxicants. They have hormone disrupting properties, meaning they interfere with the production, elimination or binding of hormones in the body. Some of the phthalates used in cosmetics block the effects of testosterone, and others used in many forms of food packaging can mimic estrogen. Phthalates found in food packaging (like DEHP) can influence expression of genes that propel production of thyroid stimulating hormone.

What do they do?

In animal studies, dangerous, endocrine-disrupting phthalates have shown to alter how reproductive organs develop in the womb, causing harmful effects with long-term consequences (Li 2020, Rattan 2018). Prenatal exposure to phthalates and other toxicants, according to scientists, can set the stage for gynecological disorders such as PCOS and make women more susceptible to other chemicals that impair fertility (Rutkowska 2016). 

One study showed that women undergoing fertility treatments with higher levels of phthalates had poor embryo quality (Machtinger 2018). Other studies (both human and animal) found that exposing pregnant mothers to phthalates disrupts and reduces testosterone in male offspring, causing a range of genital deformities and sperm issues (Swan 2009). 

One of the first signs that phthalates were a danger to fertility began in 1975 when researchers discovered that Russian factory workers who were exposed to high phthalate levels on the job had less births and more miscarriages than women who were not exposed (Aldyreva 1975). 

So, they only affect the reproductive system?

No. Phthalates also affect metabolic function. Our bodies have receptor cells called peroxisome proliferator activated receptors (PPARs) that can be triggered by phthalates. This causes the body to respond to an influx of calories abnormally -- diverting, for example, a meal of protein into fat creation rather than muscle. In his book Sicker, Fatter, Poorer, endocrine disrupting chemical (EDC) expert Leonardo Trasande, MD, MPP says, “Phthalates tell the body to grow fat cells when that might not be an optimal use of the incoming nutrition.”

One study found that 10 years after measuring exposure to phthalates, the higher the women’s phthalate exposure, the more weight she gained (Song 2014). 

They can also cause inflammation and oxidative stress, an imbalance in the body that can greatly impact the pancreas and mess with insulin-related activities.

Trasande’s own studies on adolescents found that phthalates may influence metabolism and cardiovascular risks, including high blood pressure and insulin resistance (Trasande 2013, Attina 2015, Trasande 2013).

Where are phthalates?

Unfortunately, dangerous phthalates are used in many things like food packaging, household products, drugs, shampoo, skincare, cosmetics and more to make them durable, flexible, and fragrant.

We take drugs that are coated in them (Hernández-Díaz 2013); our skin absorbs them through makeup, skincare, and shampoo; and we consume food and drink covered in them from packaging leaching (Schecter 2013). They are found in virtually everyone's urine, as well as in sweat, blood, breast milk, sperm, and ovarian fluids (Silva 2004).

Unlike other toxins that build up in fat cells, phthalates move through the body rapidly. But, scientists refer to them as "pseudo-persistent" because they are continuously replaced by other phthalates. Studies have shown that women have higher levels of phthalates than men, likely due to more frequent use of skincare, perfumes, and cosmetics (Silva 2004).

How do I avoid phthalates and their effects?

• Choose to buy from companies (like ours) whose packaging is free of endocrine disrupting chemicals (EDCs)!
• Eating less fast food, take-out and restaurant food. It’s not clear exactly where the endocrine disrupting chemicals (EDCs) are coming from, but it is likely the chemicals leach from the food packaging, processing equipment, and food-handling gloves (Zota 2016, Varshavsky 2018).
• Never microwave or heat food or drinks in plastic containers. It allows the microplastics to melt at a microscopic level and travel into your food. This includes putting plastics in the dishwasher -- just hand wash in mild water.
• Stop reusing single-use plastic containers.
• Avoid canned foods and foods covered in plastics when you can. (Rudel 2011)
• Choose products made from glass or stainless steel when possible.
• Choose “phthalate-free” products for water bottles, skincare, cosmetics, and hair care and avoid scented products for soaps, air fresheners, fabric softeners and other cleansers. We recommend “fragrance free” over “unscented,” since companies can use other chemicals to mask scents.

It’s incredibly difficult to cut out all phthalate exposure because they’re so pervasive -- but, don’t be discouraged! Small changes matter along with advocating for government policies to ban endocrine disrupting chemicals (EDCs) and find safer alternatives. Use your dollar to show that getting rid of EDCs for our health and the health of the next generation matters!

Sources:

Rutkowska AZ, Diamanti-Kandarakis E. Polycystic ovary syndrome and environmental toxins. Fertil Steril. 2016;106(4):948-958. doi:10.1016/j.fertnstert.2016.08.031

Silva MJ, Barr DB, Reidy JA, et al. Urinary levels of seven phthalate metabolites in the U.S. population from the National Health and Nutrition Examination Survey (NHANES) 1999-2000 [published correction appears in Environ Health Perspect. 2004 Apr;112(5):A270]. Environ Health Perspect. 2004;112(3):331-338. doi:10.1289/ehp.6723

Rutkowska AZ, Diamanti-Kandarakis E. Polycystic ovary syndrome and environmental toxins. Fertil Steril. 2016;106(4):948-958. doi:10.1016/j.fertnstert.2016.08.031

Machtinger R, Gaskins AJ, Racowsky C, et al. Urinary concentrations of biomarkers of phthalates and phthalate alternatives and IVF outcomes. Environ Int. 2018;111:23-31. doi:10.1016/j.envint.2017.11.011

Swan SH. Environmental phthalate exposure in relation to reproductive outcomes and other health endpoints in humans. Environ Res. 2008;108(2):177-184. doi:10.1016/j.envres.2008.08.007

Aldyreva MV, Klimova TS, Iziumova AS, Timofeevskaia LA. Vliianie ftalatnykh plastifikatorov na generativnyiu funkstsiiu [The effect of phthalate plasticizers on the generative function]. Gig Tr Prof Zabol. 1975;(12):25-29.

Song Y, Hauser R, Hu FB, Franke AA, Liu S, Sun Q. Urinary concentrations of bisphenol A and phthalate metabolites and weight change: a prospective investigation in US women. Int J Obes (Lond). 2014;38(12):1532-1537. doi:10.1038/ijo.2014.63

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Attina TM, Trasande L. Association of Exposure to Di-2-Ethylhexylphthalate Replacements With Increased Insulin Resistance in Adolescents From NHANES 2009-2012. J Clin Endocrinol Metab. 2015;100(7):2640-2650. doi:10.1210/jc.2015-1686

Trasande L, Sathyanarayana S, Spanier AJ, Trachtman H, Attina TM, Urbina EM. Urinary phthalates are associated with higher blood pressure in childhood. J Pediatr. 2013;163(3):747-53.e1. doi:10.1016/j.jpeds.2013.03.072

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Silva MJ, Barr DB, Reidy JA, et al. Urinary levels of seven phthalate metabolites in the U.S. population from the National Health and Nutrition Examination Survey (NHANES) 1999-2000 [published correction appears in Environ Health Perspect. 2004 Apr;112(5):A270]. Environ Health Perspect. 2004;112(3):331-338. doi:10.1289/ehp.6723

Li K, Liszka M, Zhou C, Brehm E, Flaws JA, Nowak RA. Prenatal exposure to a phthalate mixture leads to multigenerational and transgenerational effects on uterine morphology and function in mice. Reproductive Toxicology. 2020;93:178-190. doi:10.1016/j.reprotox.2020.02.012

Rattan S, Brehm E, Gao L, Flaws JA. Di(2-Ethylhexyl) Phthalate Exposure During Prenatal Development Causes Adverse Transgenerational Effects on Female Fertility in Mice. Toxicol Sci. 2018;163(2):420-429. doi:10.1093/toxsci/kfy042

Zota AR, Phillips CA, Mitro SD. Recent Fast Food Consumption and Bisphenol A and Phthalates Exposures among the U.S. Population in NHANES, 2003-2010. Environ Health Perspect. 2016;124(10):1521-1528. doi:10.1289/ehp.1510803

Varshavsky JR, Morello-Frosch R, Woodruff TJ, Zota AR. Dietary sources of cumulative phthalates exposure among the U.S. general population in NHANES 2005–2014. Environment International. 2018;115:417-429. doi:10.1016/j.envint.2018.02.029

Rudel RA, Gray JM, Engel CL, et al. Food packaging and bisphenol A and bis(2-ethyhexyl) phthalate exposure: findings from a dietary intervention. Environ Health Perspect. 2011;119(7):914-920. doi:10.1289/ehp.1003170