Could cadmium be responsible for some of the neurological signs and symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome
– Source: Medical Hypotheses, Jul 12, 2012
By Stefania Pacini, et al.
[Note: The heavy metal cadmium, a potential ‘immunotoxin’, is used in batteries, metal plating, and some paints and plastics; can be released into the environment by coal or oil burning, car exhaust, metal processing & other industrial operations. Based on its potential immune effects has been implicated in CFS, FM, environmental illnesses, thyroid dysfunction and more.]
According to the World Health Organization, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a neurological disease characterized by widespread inflammation and multi-systemic neuropathology.
Aetiology and pathogenesis are unknown, and several agents have been proposed as causative agents or as factors perpetuating the syndrome. Exposure to heavy metals, with particular reference to mercury and gold in dental amalgams, has been considered among the triggers of ME/CFS.
Here we hypothesize that cadmium, a widespread occupational and environmental heavy metal pollutant, might be associated with some of the neurological findings described in ME/CFS.
In fact, ME/CFS patients show a decrease of the volume of the gray matter in turn associated with objective reduction of physical activity.
Cadmium induces neuronal death in cortical neurons through a combined mechanism of apoptosis and necrosis and it could then be hypothesized that cadmium-induced neuronal cell death is responsible for some of the effects of cadmium on the central nervous system, i.e. a decrease in attention level and memory in exposed humans as well as to a diminished ability for training and learning in rats, that are symptoms typical of ME/CFS.
This hypothesis can be tested by measuring cadmium exposure in a cohort of ME/CFS patients compared with matched healthy controls, and by measuring gray matter volume in un-exposed healthy controls, exposed non-ME/CFS subjects, un-exposed ME/CFS patients and exposed ME/CFS patients.
In addition, we hypothesize that cadmium exposure could be associated with reduced cerebral blood flow in ME/CFS patients because of the disruptive effects of cadmium on angiogenesis. In fact, cadmium inhibits angiogenesis and low global cerebral flow is associated with abnormal brain neuroimaging results and brain dysfunction in the form of reduced cognitive testing scores in ME/CFS patients.
This hypothesis can be tested by measuring cerebral cortex blood flow in un-exposed healthy controls, exposed non-ME/CFS subjects, un-exposed ME/CFS patients and exposed ME/CFS patients.
If our hypothesis is demonstrated correct, the consequences could affect prevention, early diagnosis, and treatment of ME/CFS.
Implications in early diagnosis could entail the evaluation of symptoms typical of ME/CFS in cadmium-exposed subjects as well as the search for signs of exposure to cadmium in subjects diagnosed with ME/CFS.
Nutritional supplementation of magnesium and zinc could then be considered, since:
• These elements have been proposed in the prophylaxis and therapy of cadmium exposure,
• And magnesium was demonstrated effective on ME/CFS patients' symptom profiles.
Source: Medical Hypotheses, Jul 12, 2012. PMID:22795611, by Pacini S, Fiore MG, Magherini S, Morucci G, Branca JJ, Gulisano M, Ruggiero M. Department of Anatomy, Histology and Forensic Medicine, University of Firenze, Firenze, Italy. [Email: firstname.lastname@example.org]