Neurotoxins: Cause, Effect, and Prevention

Jonathan Vellinga, MD

The CDC regularly releases reports recording average levels of environmental chemicals, metals, and toxins in the general US population, and every report details increases in the number of foreign toxic chemicals found in the average person’s body (1). These toxins can affect many systems in the body and, unfortunately, the brain is included in that list. In previous articles, we’ve discussed brain health and zoomed in on the effects of brain inflammation and how it can be triggered by chronic inflammatory diseases and disorders, an unhealthy gut, disrupted blood sugar levels, and hormonal dysfunction. There is yet another culprit behind brain inflammation: neurotoxins.

Neurotoxins: Cause, Effect, and Prevention

How Do Neurotoxins Cause Brain Inflammation?

A neurotoxin is a substance that, whether naturally occurring or produced by humans, is capable of damaging the central nervous system (the brain and spinal cord). While some toxins are harmful in any amount, other substances can be tolerated in smaller doses, but if overloaded can cause adverse effects and act as neurotoxins (4). While each toxin interacts with the brain differently, there are some common effects that work together to create brain inflammation. Neurotoxins affect basic brain cell function by interfering with mitochondrial function, increasing oxidative stress, and deregulating protein turnover (3, 4). All three of these functions can result in inflammation, and when compounded with general age-related increase in oxidative stress and general antioxidant system decline, can begin the pathogenesis of a number of neurological symptoms and disorders (4).

Common Toxins

Over 200 everyday chemicals are toxic to humans, such as flame retardants, phthalates and BPA (chemicals used in plastics), pesticides, and non-stick or stain-resistant products that are perfluorinated (5). These can affect attention, memory, behavior, cognition, and even physical coordination, increasing the risk of neurodegenerative disorders such as Parkinson’s and dementia (5).

Heavy metals are another commonly found toxin that can seriously impair brain function and cause brain inflammation. Because heavy metals are used so widely in industrial, pharmaceutical, agricultural, and commercial products, they are distributed quite widely throughout the environment and, of course, affect those working in manufacturing the most (6). The toxic burden on the humans and animals near these manufacturing sites is determined by a number of factors, including (6):

  • Type of toxin, and how it interacts with the environment

  • Amount of toxin present

  • Exposure type (oral, airborne, physical)

  • Population of the humans/animals themselves (age, gender, genetics, nutritional status)

The most toxic heavy metals are systemic toxins, which can cause multiple-organ damage, even at relatively low levels of exposure (6). The most common heavy metals are arsenic, chromium, lead, cadmium, and mercury (6).


Arsenic is widely used in insecticides, herbicides, and wood preservatives, though it can also be found in medicine, electronic, and industrial manufacturing processes (7). It can attach to other particles easily, including molecules in the air, water, and soil, and dissolves and spreads rapidly (7). Arsenic is thus able to contaminate entire lakes, rivers, or other water sources through contact with rain, snow, or industrial waste. This is why water is the biggest source of arsenic poisoning, with several millions of people being exposed every year (7, 8). However, food, cigarettes, and the products listed above can also cause arsenic poisoning (7). While cigarettes do contain low levels of arsenic, they may actually do the most harm by causing impairment of the ability to process ingested arsenic and expel it from the body (7).

Arsenic is not only associated with brain inflammation, but also brain dysfunction, increased risk for Alzheimer’s disease, and altered blood-glucose and HPA pathway functioning (8). Unfortunately, the most concentrated areas of arsenic pollution are Taiwan, China, India, and the Western U.S. (8).