Parkinson’s disease is a progressive disorder of the central nervous system. In Parkinson’s, the dopaminergic neurons in the substantia nigra and non-dopaminergic, projecting nerve fibers in the caudate and putamen nuclei that control circuits for sensory, associative, premotor, and motor pathways are severely affected. This results in disordered movement, including tremor, rigidity, and difficulty with balance and coordination. Parkinson’s disease is the most common movement pathology in the United States. In fact, based on the US Census Bureau’s population projections, researchers estimate that there will be approximately 930,000 people over the age of 45 diagnosed with the disorder by the end of 2020 and 1,238,000 by the end of 2030. Therefore, it’s important for us as practitioners to understand the condition and the various ways we can provide relief to our patients and help preserve their quality of life as much as possible.
Oxidative Stress and Parkinson’s Disease
A growing body of evidence suggests that a comprehensive, integrative approach may be beneficial in the treatment of Parkinson’s disease. Although the underlying cause of Parkinson’s disease is poorly understood, research suggests that Parkinson’s disease-induced neurodegeneration is propagated by oxidative stress. This is because the process of metabolizing dopamine itself results in free radical formation. The increase in reactive oxygen species that takes place as a result of this process triggers a sequence of events that leads to neuronal cell death.
Glutathione is a thiol tripeptide that serves as a potent antioxidant within the body. Research looking at the postmortem central nervous systems of patients with Parkinson’s disease demonstrated that Parkinson’s patients had lower levels of glutathione in the substantia nigra, but not in other parts of the brain, compared to controls. Furthermore, the greater the decrease in glutathione, the more severe the disease tended to be. With higher levels of reactive oxygen species and with lower levels of glutathione within the substantia nigra, it is certainly plausible that oxidative stress could be a significant contributing factor toward Parkinson’s-related neurodegeneration.
Because of its role in protecting the brain from oxidative stress-induced damage by reducing reactive oxygen species, glutathione has been suggested as a potential adjunctive therapy in the treatment of Parkinson’s disease. In a small study that looked at treatment-naïve patients with early-stage Parkinson’s disease, glutathione was administered intravenously at a dosage of 600 mg twice daily for 30 days.
The glutathione was discontinued after 30 days and the patients were examined at 1-month intervals for 2-4 months. They were then treated with carbidopa-levodopa. At the end of the study, researchers reported significant improvement after glutathione therapy with a 42% decline in disability. They concluded that intravenous glutathione may be an effective means of alleviating symptoms and delaying the disease’s progress in individuals with early-stage, treatment-naïve Parkinson’s disease.
Mucuna pruriens and Parkinson’s Disease
L-DOPA, also known as levodopa and l-3,4-dihydroxyphenylalanine, is an amino acid precursor to the neurotransmitter dopamine. L-DOPA crosses the blood-brain barrier and increases dopamine concentrations within the brain. L-DOPA is prescribed as a dopamine replacement agent in cases of Parkinson’s disease.
Velvet bean (Mucuna pruriens) is a botanical product that naturally contains L-DOPA. A small study involving patients with advanced Parkinson’s demonstrated that Mucuna pruriens, at both high and low doses, was as effective and safe as levodopa/benserazide.5 Another small study demonstrated that Mucuna pruriens powder may cause undesirable gastrointestinal side effects in some patients, but for those who tolerated it, the clinical response was similar to that of levodopa-carbidopa.
Other integrative therapies in the treatment of Parkinson’s Disease
In addition to supplementing glutathione and other potent antioxidants and supporting optimal dopamine levels within the substantia nigra, an integrative approach in the treatment of Parkinson’s disease may involve:
1. decreasing caloric intake;
2. balancing essential fatty acid intake by decreasing pro-inflammatory fatty acids and increasing anti-inflammatory fatty acids;
3. increasing acetyl L-carnitine, coenzyme Q10, NADH, and the membrane phospholipid phosphatidylserine;
4. chelating heavy metals, as indicated;
5. and providing liver cytochrome P450 detoxification support.
As practitioners, it’s up to us to decide which, if any, of these interventions would be beneficial to our patients. Ideally, this should be a collaborative decision between our patients and us. These decisions need to be made on a case-by-case basis in order to provide optimal, patient-centered care to the people who entrust us with their most precious commodity—their health. Because we carry such a great responsibility, it’s important for us to familiarize ourselves with the interventions that are available to us as well as the research that supports or discourages their use.
1) Marras, C., Beck, J., Bower, J., Roberts, E., Ritz, B., Ross, G., Abbott, R., Savica, R., Van Den Eeden, S.K., Willis, A., & Tanner, CM. (2018). Prevalence of Parkinson’s disease across North America. npj Parkinson's Disease. 4. 10.1038/s41531-018-0058-0.
2) Hwang O. (2013). Role of oxidative stress in Parkinson's disease. Experimental neurobiology, 22(1), 11–17. doi:10.5607/en.2013.22.1.11
3) Sian, J., Dexter, D.T., Lees, A.J., Daniel, S., Jenner, P., & Marsden C.D. (1994). Glutathione-related enzymes in brain in Parkinson’s disease. Ann Neurol. 36:356–361.
4) Sechi, G., Deledda, M., Bua, G., Satta, W., Deiana, G., Pes, G., & Rosati, G. (1996). Reduced intravenous glutathione in the treatment of early Parkinson's disease. Progress in neuro-psychopharmacology & biological psychiatry. 20. 1159-1170. 10.1016/S0278-5846(96)00103-0.
5) Cilia, R., Laguna, J., Cassani, E., Cereda, E., Pozzi, N. G., Isaias, I. U., … Pezzoli, G. (2017). Mucuna pruriens in Parkinson disease: A double-blind, randomized, controlled, crossover study. Neurology, 89(5), 432–438. doi:10.1212/WNL.0000000000004175
6) Cilia, R., Laguna, J., Cassani, E., Cereda, E., Raspini, B., Barichella, M., Pezzoli, G. (2018) Daily intake of Mucuna pruriens in advanced Parkinson's disease: A 16-week, noninferiority, randomized, crossover, pilot study. Parkinsonism Relat Disord, 49:60-66.
7) Kidd, P. (2001). Parkinson's disease as multifactorial oxidative neurodegeneration: Implications for integrative management. Alternative medicine review: a journal of clinical therapeutic. 5. 502-29.