01/18/2026
BLOOD-BRAIN BARRIER:
Current studies provide us with a list of environment chemicals that cause or contribute the breakdown of the blood-brain barrier which allows toxins, pathogens, and inflammatory molecules to enter the brain and cause or contribute to neurological disorders and cognitive impairment.
Heavy Metals such as lead, cadmium, mercury and arsenic, directly damage endothelial cells, disrupt tight junction proteins, and can mimic essential ions, allowing them to cross the BBB. Increased permeability allows these harmful metals to accumulate in the brain where they cause neuro-toxicity, inflammation, oxidative stress, and neurodegenerative diseases. Methylmercury easily crosses the BBB, causing severe encephalopathy, while inorganic mercury also damages the barrier.
Aluminum has been shown to decrease the expression of key tight junction proteins which are essential for maintaining the barrier's integrity. Aluminum enhances the permeability for certain lipophilic (fat-soluble) substances allowing substances like peptides (such as beta-endorphin and delta-sleep-inducing peptide) and hormones to pass into the brain more easily.
Phthalates (DEHP): Can impact cerebrovascular function and increase BBB permeability, potentially due to endocrine-disrupting effects.
PFAS (Per- and Polyfluoroalkyl Substances): Known to pe*****te and accumulate in the brain, indicating BBB transmission.
Air Pollutants (Vehicle Emissions): Cause oxidative stress, increase matrix metalloproteinase (MMP) activity (degrading barrier proteins), and promote inflammation (IL-1β), disrupting the BBB.
Organochlorine Pesticides & PCBs: Identified as neurotoxicants that can affect brain development and barrier function.
Toxins (Dioxins, Toluene): Other industrial chemicals linked to developmental neurotoxicity and barrier issues.
