What could connect such disquieting and disparate health concerns as early onset puberty, female depression, and fatty liver disease? Endocrine disrupting chemicals (EDCs) are leading candidates for all of these health aberrations. Moreover, these chemicals have become ubiquitous in the contemporary U.S. environment as well as globally. Virtually all humans born today are exposed to a variety of chemicals, especially EDCs that are measurably detectable in common products and in most humans.
Despite the health risks, these chemicals have not received enough public attention. This warrants greater action from the medical and scientific community to ensure policymakers are informed.
The Impact of EDCs on Certain Disease States
Early Onset Puberty
Studies show that the age of pubertal onset has declined continuously for 3 decades, and evidence suggests EDCs may play a role. More specifically, this may be related to the multitude of EDCs that include bisphenol A (BPA), polyfluoroalkyl substances (PFAS), and polybrominated diphenyl ethers (PBDE). Experimental research suggests a causative role for these chemicals: in particular, EDCs are actively disrupting function at several levels of the hypothalamic-pituitary-gonadal axis as well on peripheral tissues. EDCs disrupt the gonadotropin-releasing hormone (GnRH) pulsatile release and also alter several epigenetic mechanisms that may have transgenerational effects.
One area warranting further study is whether EDCs are synergistic with one another. However, there is already substantial evidence that this is the case, and that certain interactions can effect neurodevelopment. For example, one complex study found increased risk of language delay among the offspring of more than half of the pregnant women in the study who had been exposed to an EDC mixture — a remarkably high prevalence.
Hormone Signaling and Depression
Research suggests that EDCs interfere with hormone signaling and increase human vulnerability to neuropsychiatric disorders. Moreover, evidence is accumulating that they impair serotonergic neurotransmission, thus contributing to the development of depression and its concomitants. There is mounting evidence that these chemicals are associated with increased risk of depression in the peripartum period of mothers, while other studies suggest early exposure to EDCs including in breast milk may contribute to depression later in childhood and adolescence.
Fatty Liver Disease
EDCs have also been implicated in a range of physical disorders increasing in the 21st century, including fatty liver disease and diabetes mellitus. Fatty liver disease includes non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH), which can progress to cirrhosis (end stage liver disease) or even the highly lethal hepatocellular cancer. Of note, the U.S. is not alone in this epidemic. Recent research suggests nearly one-third of adults worldwide have NAFLD, with a U.S. prevalence perhaps as high as 38% of the adult population.
EDCs acting in concert with a high fat diet and high fructose and sucrose intake may further contribute to fatty liver disease and early EDC exposure may be crucial. Adolescents with NAFLD have an increased chance of developing depression at ages 15-17 compared to those without it. Moreover, investigators in another study observed 11.6% of female adolescents with NAFLD had suicidal tendencies. In the past decade, NAFLD and its sequelae have become the leading cause of liver transplantation in women in the U.S. This costly and difficult procedure does not guarantee a normal life expectancy, although it is highly effective at preventing immediate death from hepatic failure.
Spermatogenesis and Romeo Too
So far we have focused exclusively on the impact of these ubiquitous toxic chemicals on women, suggesting “Juliet” may be getting poisoned without realizing it. But “Romeo” is not spared either. EDCs have been shown to impair spermatogenesis, and may contribute to reduced male fertility. With the birthrate in the U.S. falling for the sixth consecutive year (echoing global trends), it’s worth exploring further whether these may be inter-related phenomena.
Growing evidence suggests EDCs may be linked to more severe COVID-19 outcomes because they can localize to lung tissue, contribute to immune dysregulation, and promote neuroinflammation.
There are other health risks of EDCs that we haven’t mentioned in this brief essay.
Informing Policymakers and the Public
Of course, not all chemicals have the same effects on various disease states and severity: some are more toxic than others and have different health outcomes. But these chemicals are highly prevalent — they are found in a wide range of foods, water, personal products, and packaging. In addition to phthalates, BPA, and PFAS, other environmental toxins including air pollution, pesticides, and herbicides may be adding to this burden of toxicant related disorders.
Shouldn’t this raise serious questions among physicians, scientists, and policymakers to ensure the public is better informed of the health risks? Given the dangers of these chemicals it is indeed surprising that the public is not better informed. However, first it is up to the medical and scientific community to inform policymakers of the risks involved. But medical scientists and practitioners alike tend to be narrowly focused on the issues concerning to their specific disciplines while avoiding engagement with broader issues of health and disease. This has led to lack of knowledge about population health risks of environmental toxicants among other complex issues. More attention should be given to the insights of professors of environmental health who are often found in schools of public health.
While the Biden administration made a recent move to label certain “forever chemical” as hazardous, more needs to be done. Without a better-informed public and policymakers, efforts to mitigate the risks of chemical toxicity and develop sound public policy won’t go far enough. It’s essential we limit the manufacture and/or distribution of such damaging chemicals, and increase clinical research on how to minimize the adverse health effects of these unfortunately ubiquitous substances.
The future of humans is fraught chemically as well as climatologically. Can’t the medical scientific community lead more effectively on this health matter of imminent peril?
Arnold R. Eiser, MD, MACP, is an adjunct fellow at the Center for Public Health Initiatives and an adjunct senior fellow at the Leonard Davis Institute at the Perelman School of Medicine. He is the author of Preserving Brain Health in a Toxic Age: New Insights from Neuroscience, Integrative Medicine, and Public Health. Barbara Demeneix, PhD, DSc, is professor emeritus of Comparative Physiology at the National Museum of Natural History in Paris, and chair of the Endocrine Society’s EU EDC Taskforce. She is the author of Losing Our Minds, Toxic Cocktail, and Comment les énergies fossiles détruisent notre santé, le climat et la biodiversité.