What are hormone disruptors, and are they really found in everyday products?

Hormone disruptors, also known as EDCs (endocrine-disrupting chemicals), are chemicals that can mimic, block, or otherwise interfere with the human hormonal system. They are found in a remarkably wide range of everyday items: plastic food packaging, toys, cosmetics, cleaning products, rain jackets, till receipts, air fresheners, and even in dummies and brake fluid. That this is not merely theoretical is shown by measurements: these substances are demonstrably present in the blood, urine, fatty tissue, and amniotic fluid of people.

Food is one of the largest routes of exposure. EDCs are found not only in plastic bottles and food packaging, but also naturally in certain plant-based foods. Vegetables, fruit, green tea, chocolate, and red wine contain so-called phytoestrogens: plant compounds that resemble oestrogen. This makes 'avoiding them completely' practically almost impossible, and for individuals there is currently no meaningful way to measure their own exposure.

The health risks are best documented in relation to reproduction and pregnancy. In women, substances such as BPA (a compound found in certain plastics), plasticisers from plastics, pesticides, and dioxins are associated with disrupted ovulation, endometriosis (uterine lining tissue that grows outside the uterus), and poorer IVF outcomes. In men, the concerns involve lower testosterone levels and reduced sperm quality. This association is plausible but has not yet been fully proven as causal; the evidence consists largely of observational research.

Pregnant women and unborn children are the most vulnerable group. BPA and plasticisers from plastics have been linked to pregnancy complications such as high blood pressure, restricted fetal growth, and gestational diabetes, and possibly also to a higher risk of obesity and cardiovascular disease in the child later in life. A large analysis of epidemiological studies also found associations between certain EDCs, including banned pesticides, substances used in non-stick coatings, and preservatives from cosmetics, and an increased risk of breast cancer. Here too, association is not the same as proven causation.

Some EDCs are called 'obesogens' because they may promote fat storage and disrupt metabolism. That hypothesis is biologically plausible, but significant knowledge gaps remain. An illustrative example is lilial, a fragrance ingredient that the EU banned due to reproductive toxicity: laboratory research in cells found no hormone-disrupting effect whatsoever, which shows how complex and sometimes contradictory the research into individual substances still is.