Microplastics and Forever Chemicals: Why Your Body Can't Detox Them — and What It Actually Needs — The hormonal hijacking

This is the Netflix angle &#8212; and it&#8217;s real. BPA binds directly to estrogen receptors ER&#945; and ER&#946; at nanomolar affinities, meaning it activates estrogen signaling at concentrations vastly lower than what most people assume is &#8220;safe.&#8221; In men, it interferes with luteinizing hormone binding in the Leydig cells of the testes, which is the trigger that normally tells those cells to make testosterone. It also disrupts INSL3, the hormone responsible for testicular descent in fetal development &#8212; which is why BPA exposure during pregnancy is associated with cryptorchidism in male offspring. Phthalates &#8212; particularly DEHP and its metabolite MEHP &#8212; work through a different mechanism but arrive at similar destinations. They suppress StAR protein, which is the cholesterol transporter that moves cholesterol into mitochondria for steroid hormone synthesis. Without StAR, testosterone production drops at the source. In women, phthalates induce oxidative stress within ovarian follicles and accelerate follicular atresia, reducing ovarian reserve. Men in the highest quartile of urinary phthalate metabolites have roughly 12% lower serum testosterone than the lowest quartile. PFAS add a third layer: they activate PPAR&#945; and PPAR&#947;, nuclear receptors that regulate lipid metabolism, steroidogenesis, and thyroid signaling. The downstream effect