- The experimental animal literature consistently shows that the structure and function of the brain’s neuroendocrine systems can be altered by developmental exposures to EDCs.
- The adult neurobiological consequences of developmental exposures include alterations in peripheral hormones and changes in behaviors.
- Underlying mechanisms of EDC actions in the brain include molecular and cellular changes in expression of particular genes and proteins involved in neuroendocrine and other behaviors, including those involved in cognitive and affective functions.
- The brain is highly vulnerable to EDC exposures because of the widespread distribution of nuclear hormone receptors, steroidogenic enzymes, and neurotransmitter systems on which EDCs can act.
- Strong experimental evidence in animals shows that there are sex differences in EDC effects on the brain. Moreover, epidemiological work also shows that relationships between body burdens of chemicals and particular behaviors often differ between the sexes in human studies.
- In humans, epidemiological data support associations between higher exposures to EDCs with decreased IQ, increased neurodevelopmental problems, and other neurocognitive outcomes.
- Future research needs to focus on sex differences in endocrine disruption of the brain and to consider both age of exposure and age at assessment in interpreting results.
This hypothesis, which clearly needs to be substantiated, can lead to a more productive dialogue around gender identity disorders, removing the issue from the psychological realm, which is only one aspect of the problem. There will be less blame and judgement, less guilt and shame, more respect and compassion. Recognition of the likely link between EDC’s and gender identity disruption might also motivate a change in some of our laws, which are too permissive of these chemicals’ presence in our lives
(1) Gore AC, Chappell VA, Fenton SE, et al. EDC-2: The Endocrine Society’s Second Scientific Statement on Endocrine-Disrupting Chemicals. Endocr Rev. 2015;36(6):E1-E150
(2) Intellectual impairment in children exposed to polychlorinated biphenyls in utero. Jacobson JL, Jacobson SW N Engl J Med. 1996 Sep 12; 335(11):783-9.