So many everyday chemicals have been associated with disturbances in the endocrine system, which in a broader sense can be related to problems with reproduction, cancers, thyroid, obesity, metabolism and neurodevelopment. It's time to learn about what is under YOUR hood!
What are endocrine disruptors?
One of the body's key balancing and messenger systems is the endocrine system. It relies on hormones. Unfortunately, a variety of chemicals, both natural and man-made, may mimic or interfere with our hormones. Called "endocrine disruptors", these chemicals are linked with developmental, metabolic, reproductive, brain, immune, and other problems.1 They can have such far-reaching outcomes because once absorbed into the body, they can either decrease or increase normal hormone levels, sometimes by facilitating the body's natural hormones and activating pathways, or by obstructing endocrine receptors and prohibiting reactions. Endocrine disruptors are ubiquitous and found in many everyday products, so they are worth reviewing. These include some plastic bottles and containers, liners of metal food cans, foods themselves, nonstick pans, paper, cosmetics, detergents, flame retardants, food, toys, carpet, anti-microbial personal care products, furniture foam, pesticides and more.
Contact with endocrine disruptors comes in many forms. Though some of these compounds we knowingly encounter every day, others may be more of an occupational hazard and/or perceived as less likely to encounter. However, environmental exposures, such as ground water contamination, have sometimes left communities affected which would have otherwise not have occurred. These include results from the production of munitions, electrical or aerospace equipment, automobiles and much more.
Chemicals that can interfere with proper endocrine system functioning include, but are not limited to:
Bisphenol A (BPA) - BPA is used to make polycarbonate plastics and epoxy resins, which are found in many plastic products including food storage containers, from where it can leach into food consumed by people. BPA is also used in production of polycarbonate tableware, water bottles, and baby bottles. The degree to which BPA leaches from polycarbonate bottles into liquid may depend more on the temperature of the liquid or bottle, than the age of the container.2 BPA can also be found in most samples of human breast milk studied and as much as 93% of a healthy infant population urine samples, aged 3–15 months, who were without known environmental exposure to BPA.3
Dioxins - 'Dioxins' is a term commonly used for a group of compounds that have a similar chemical structure and are produced as byproducts in the making of pesticides, herbicides, paper bleaching and waste burning. This family of chemicals has come to include polychlorinated dibenzo-para-dioxins (PCDDs), polychlorinated dibenzo-furans (PCDFs), certain dioxin-like polychlorinated biphenyls (PCBs), and more. These chemicals are known as "persistent organic pollutants" (POPs) because they have a much longer half-life than so many other compounds. Dioxins are of concern because of their highly toxic potential. Experiments have shown they affect a number of organs and systems. Once dioxins enter the body, they last a long time because of their chemical stability and their ability to be absorbed by fat tissue, where they are then stored in the body. Their half-life in the body is estimated to be 7 to 11 years, 4 whereas the half-life for BPA is as short as six hours.3 And though a recent study from 2022 found declining contamination levels in breast milk during the last decade among German mothers for multiple types of dioxins, they still concluded "the need to further reduce the environmental contamination with persistent substances and subsequently the exposure in childhood".5
Perchlorate - Perchlorate is a white crystalline solid or colorless liquid that is both a naturally occurring and man-made anion. "It is highly soluble in water, and relatively stable and mobile in surface and subsurface aqueous systems. As a result, perchlorate plumes in groundwater can be extensive".6 This by-product of aerospace, weapon, fireworks and pharmaceutical industries has been found in contaminated drinking water and food. It can have devastating effects on the thyroid of exposed persons.
Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) - PFAS are used widely in industrial applications, with more than 4,700 of these man-made compounds in circulation. They appear in such diverse applications as firefighting foams and non-stick pans, stain-resistant clothes and carpets, paper, textile coatings, and more. PFAS molecules are made up of a chain of linked carbon and fluorine atoms. "Because the carbon-fluorine bond is one of the strongest, these chemicals do not degrade in the environment. In fact, scientists are unable to estimate an environmental half-life for PFAS ...",7 which should really bring comfort to no one! People are most likely exposed to these chemicals by consuming PFAS-contaminated water or food, using products made with PFAS, or breathing air containing PFAS. "The research conducted to date reveals possible links between human exposures to PFAS and adverse health outcomes. These health effects include altered metabolism, fertility, reduced fetal growth and increased risk of being overweight or obese, and reduced ability of the immune system to fight infections".7 Sadly, one report by the Centers for Disease Control and Prevention’s National Health and Nutrition Examination Survey (NHANES) found PFAS in the blood of 97% of Americans.8
Phthalates - Ortho-phthalates, called just 'phthalates' for short, are used to make plastics more flexible. Overwhelming abundant in modern manufacturing, they appear in numerous consumer products including food production materials and packaging, medical supplies and coatings of medicines, flooring, wall coverings, and other home materials, as well as cosmetics and other personal care products. Approximately 4.9 million metric tons are produced annually worldwide.9 Regrettably, as mounting evidence of neurotoxicity from exposure has developed, sometimes manufacturers have simply substituted one implicated phthalate for another similar compound which has not yet achieved a burden of proof.10
Phytoestrogens - Phytoestrogens are naturally occurring substances in plants that have hormone-like activity, such as genistein and daidzein that are in soy products, like tofu or soy milk. They can have medicinal benefits in conditions attributable to low levels of estrogens, however, benefits for conditions like breast cancer have been much harder to substantiate without controversy.
Polybrominated diphenyl ethers (PBDEs) - PBDEs are a class of flame retardants used for household products such as furniture foam, textiles and carpets. They are also used in electronics and plastics to reduce the risk of ignition and slow down burning rates. PBDEs have been shown to leach into the surrounding environment and have been globally detected in soil, sediment, food, and air.11 Measures of PBDEs in house dust indicate widespread contamination in homes and house dust may be an important human exposure pathway.12 Though some types of PBDEs were voluntarily discontinued for production in the U.S. in 2004 and again in 2013 after intense scientific scrutiny and concern, other types, such as DecaBDE continue to be produced and used in the U.S., primarily in television casings. DecaBDE is classified as a possible human carcinogen by the U.S. Environmental Protection Agency.13 Is it any wonder then that "[i]n the U.S., PBDE levels in people are generally 10–100 times higher than levels measured in people in Europe and Asia".13
Polychlorinated biphenyls (PCBs) - PCBs were used to make electrical equipment like transformers, and in hydraulic fluids, heat transfer fluids, lubricants, and plasticizers; however, PCBs have been banned in the United States since 1977 and are out of use or highly restricted throughout much of the world. These compounds, which are fat-soluble and structurally similar to DDT, are highly stable. That means PCBs "...made and used for nearly 50 years before the ban remain in the environment and are found throughout the food chain, including in human tissues and breast milk".15 That makes them still able to have very undesirable effects on people, animals, and the environment. Indeed, a review from 2020 on environmental endocrine disruptors influencing the development of breast cancer summized "BPA, DDT, and PCBs assessment coincided in five key characteristics of human carcinogens as i) they alter cell proliferation, cell death, or nutrient supply, ii) they are genotoxic, iii) they are immunosuppressive agents, iv) they induce epigenetic alterations, and v) they induce oxidative stress. In addition, ... PCBs happen to induce chronic inflammation".16
Triclosan - This compound may be found in some anti-microbial and personal care products, like liquid body wash, sanitizers, soaps, deodorants, toothpastes, shaving creams, mouth washes and cleaning supplies. Higher urinary concentration levels of triclosan have been correlated with increased incidence of infertility, asthma, allergies, food sensitization, spontaneous abortion rates and more.17 Triclosan in animals induced liver fat accumulation and disrupted multiple physiological processes including drug metabolism, sucrose metabolism, fat metabolism and bile secretion. It even promoted dysregulation of pro-inflammatory genes.18 The doors have begun to close on triclosan: in 2017, the Food and Drug Administration (FDA) declared that triclosan is not generally recognized as safe and effective for antiseptic products intended for use in health care settings and the year before that the FDA also banned over-the-counter consumer antiseptic wash products containing triclosan from being marketed to consumers. These products include liquid, foam and gel hand soaps, bar soaps, and body washes. Despite this ban, the FDA allows for the continued use of triclosan in other hygiene products, including toothpaste. Though some manufacturers have voluntarily discontinued its use, others like Colgate-Palmolive Company, have opted to keep triclosan as an ingredient.
What features make these endocrine disruptor chemicals such a concern?
Some endocrine-disrupting chemicals are slow to break-down in the environment. That characteristic makes them potentially hazardous over time. Since people are typically exposed to multiple endocrine disruptors at the same time, assessing public health effects is difficult at best. Scientists and health advocates are often playing 'catch-up', trying to establish the burden of proof once these compounds have already been let loose into the public. Endocrine disrupting chemicals have been shown to cause adverse effects in animals. Increasing amounts scientific information exists on potential health problems in humans and regulatory changes are often piecemeal, as evidenced with triclosan.
Be sure to check our next blog for some ideas about reducing your exposure and body burden from endocrine disruptors!!
References:
1. Endocrine Disruptors and Your Health. National Institute of Environmental Health Sciences. 2020. May.
5. Fromme, H. et al. Polychlorinated dioxins and dibenzofurans (PCDD/F), polybrominated dioxins and dibenzofurans (PBDD/F), polychlorinated biphenyls (PCB), polybrominated diphenyl ethers (PBDE), and per- and polyfluoroalkyl substances (PFAS) in German breast milk samples (LUPE 8). Sci Total Environ. 2022 Jun 15;825:154066.
7. National Institutes of Health, National Institute of Environmental Health Sciences. Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS). Accessed 4-30-22.
9. Engel, S. et al. Neurotoxicity of Ortho-Phthalates: Recommendations for Critical Policy Reforms to Protect Brain Development in Children. Am J Public Health. 2021 Apr;111(4):687-695.
11. Hites, R. Polybrominated diphenyl ethers in the environment and in people: a meta-analysis of concentrations. Environ Sci Technol. 2004 Feb 15;38(4):945-56.
12. Harley, K. et al. PBDE concentrations in women's serum and fecundability Environ Health Perspect. 2010 May;118(5):699-704.
16. Calaf, G. et al. Endocrine disruptors from the environment affecting breast cancer (Review). Oncology Letters 20.1 (2020): 19-32.
The content and any recommendations in this article are for informational purposes only. They are not intended to replace the advice of the reader's own licensed healthcare professional or physician and are not intended to be taken as direct diagnostic or treatment directives. Any treatments described in this article may have known and unknown side effects and/or health hazards. Each reader is solely responsible for his or her own healthcare choices and decisions. The author advises the reader to discuss these ideas with a licensed naturopathic physician.