Human beings are living longer. The population of men and women aged 65 and older is expected to double between now and 2050, and as that population ages, more research is being devoted to understanding how to prevent debilitating neurological illnesses.
A new paper, written by Elizabeth Grossman and published in the peer-reviewed journal Environmental Health Perspective, investigates the links between early exposure to environmental contaminants and later occurrences of neurological disorders such as Alzheimer’s, Parkinson’s and dementia.
Genetic predispositions to these illnesses is well-documented, but a growing body of evidence is linking cognitive dysfunction to cumulative exposure to metals, solvents and pesticides.
For example, in the last decade, scientists have linked chronic low-level lead exposure to decreased cognitive abilities. Lead builds up in bones over time, so correlation between lead exposure and illness is not always established. Lead and mercury both contribute to a type of neuronal plaque that is associated with Alzheimer’s disease.
Lead, manganese, solvents, and pesticides like paraquat and maneb have been linked to symptoms that are characteristic of Parkinson’s – in both acute and chronic exposure cases.
Cadmium, like lead, also builds up in the body over time – in kidneys, liver, joints and other tissues. Rodent studies have shown that cadmium can interfere with how the body uses calcium and zinc, both important minerals to nervous system function.
The buildup of chemicals in the human body can also lead to symptoms that prevent healthy living. Dioxins, polychlorinated biphenyls (PCBs), halogenated flame retardants and pesticides can all interfere with human hormones and promote obesity and diabetes. This increases the risk of hypertension and cardiovascular disease, which in turn lead to neurodegenerative effects by reducing oxygen to brain cells.
Long-term exposure to BPA, found in polycarbonate plastics and epoxy resins, has also been associated with hypertension and adverse neurological effects.
When chemicals interfere with human hormones, they decrease the potential for exercise, which is crucial for the elderly to maintain strong physical and cognitive function. As Grossman concludes,
“At this point, there may be more research questions than answers, but evidence thus far strongly suggests environmental factors can play an instrumental role in influencing neurological function in older adults. Chemical exposures can produce health effects that set the stage for neurological disease and disorders, while physical and intellectual exercise foster brain flexibility and a healthy cognitive reserve.”