Parkinson’s Disease - Naturopathic Approaches

Parkinson’s disease is one of the most common chronic and progressive neurodegenerative disorders. It typically begins after the age of 50, and it affects approximately 1% of individuals over 60. The lifetime risk of developing this condition is 2% for men and 1.3% for women.^[1] The characteristic resting tremor, rigidity, postural instability, masked facial expression, and shuffling gait are often exhibited by people with Parkinson’s disease. However, nonspecific symptoms occur many years before with variable rate of disease progression. Many point to symptoms retrospectively, such as constipation and decreased sense of taste and smell, as early signs in the preclinical stage. Mood and sleep-related disorders are other nonmotor symptoms that may manifest. A decreased range of facial expressions as well as softness of voice are signs that family members may notice. Akinesia (lack of movement) and bradykinesia (slowness of movement) eventually become more noticeable as disease progresses.

The underlying cause of the disease remains unknown, but the hallmark of the pathology of disease progression are the death of dopaminergic neurons in the brainstem and the presence of Lewy bodies in the neurons. Due to the wide variety of symptoms between individuals and rate of progression, it is likely that both genetics and environmental exposures form its multiple risk factors. It has been found that Parkinson’s disease is more prevalent with increased exposures to pesticides and heavy metals.^{[2, 3]} The Braak hypothesis, put forth by the German pathologist Hideo Braak, suggests that the disease begins in the lower brain stem, and it is not until later in its progression that the dopaminergic neurons of the substantia nigra is affected.^[4] The mitochondial complex I has also been implicated to be dysfunctional in the disease, allowing the production of reactive oxygen species, causing dopaminergic neuronal cell death.^[5] Genetic susceptibilities of the disease are implicated through the discovery of genes linked to rare familial forms. A diagnosis of Parkinson’s disease is based on clinical signs, and often by excluding other neurodegenerative disorders first. At least two of the three major symptoms are present (resting tremor, rigidity, and bradykinesia), and often confirmed with dopaminereplacement medications such as levodopa, a dopamine precursor.

Exercise

As Parkinson’s disease is characterized by the gradual decline in motor functions and coordination, exercise is an important component of the overall health promotion to delay or reverse the functional decline for the Parkinson’s patient. Evidence supports exercise as being beneficial with regards to physical functioning, strength, balance, and gait speed.^[7] While medication is able to address the motor symptoms in early stages of the disease, exercise may also address the nonmotor symptoms of mood and sleep disorders which can improve quality of life. Animal studies suggest that aerobic exercise may also be neuroprotective to slow the progression of the disease.^[8] Exercise is also helpful in reducing anxiety and depression.^[9] Various exercises have been studied, and it appears that the best strategy is to choose an exercise program that can be sustained based on enjoyable personal preference. Aerobic exercise has the benefits of improving energy levels, improving mood, and slowing disease progression while maintaining and improving balance.

Tai chi, an ancient Chinese martial art, has been shown to reduce the risk of falls in an older population without Parkinson’s.^[10] While there are many styles of tai chi, its emphasis on slow, deliberate, smooth movements, with a focus on deep and relaxed breathing, allows for qi, or internal flow of energy, to be harnessed for health purposes. Preliminary reports of tai chi for Parkinson’s show some efficacy in prevention of falls,^[11] balance,^[12] and mobility.^[12] Cognitive functions such as visuomotor tracking and attention, working memory, processing speed, and task switching were improved in one study.^[13] The health benefits of using safe exercises such as tai chi promises to be effective in overall health promotion. Similarly, yoga, as in the form of physical practice of its various asanas or postures from the Indian tradition, can also offer great health benefits by promoting flexibility, strength, and balance for the Parkinson’s patient, and potentially grant benefit to mood through its meditative breathing exercises. One case report concluded that incorporating yoga into a physical therapy program for a Parkinson’s patient improved muscle strength and balance after twelve weeks.^[14] A randomized, controlled study suggests that yoga practice improves motor function, which likely resulted from improvements in balance, strength, posture, and gait.^[15]

Nutrition and Supplements

A large prospective study in the Netherlands found that a high dietary omega-3 intake from plant-based alpha-linolenic acid was associated with a decreased risk of Parkinson’s disease.^[16] Therefore, a diet with foods rich in omega-3 fatty acids such as salmon, walnuts, and other nuts and seeds is encouraged, both as a risk reduction and treatment of the disease. For patients on dopamine therapy, a low-protein diet, by reducing protein intake to 0.75–0.8 g/kg body weight per day, would allow more levodopa to gain entry into the brain;^[17] however, this should be used with caution to ensure that adequate nutritional requirements are obtained by the individual. As mitochondrial dysfunction has been implicated in the disease, cytidine diphosphate (CDP)-choline, or citicoline, may have neuroprotective properties for Parkinson’s disease, as it is involved in phospholipids synthesis, which in turn is important for the production and repair of mitochondrial membranes.^[18] Studies found that by supplementing CDPcholine, it allowed for a 50% reduction in levodopa dosage with the same symptom control.^[19] CDP-choline may enhance levodopa therapy by decreasing reuptake of dopamine at the synapse, as well as activating dopamine production.^[20] When taking CDP-choline, levodopa dosage should be reduced, as it can worsen levodopa side effects and increase dyskinesias.

Coenzyme Q10 (CoQ10) is significantly reduced in the mitochondria of Parkinson’s patients.^[21] Supplementing CoQ10 can help reduce cellular dysfunction and has been shown to reduce the loss of dopaminergic neurons in a mice model,^[22] which preserves the cells’ ability to produce dopamine. In humans, it has been shown to be of benefit with high daily doses,^[23] in doses up to 1200 mg per day in divided doses. Caffeine has been linked to reduced risk of Parkinson’s disease.^[24] It has also been shown helpful in easing freezing of gait in patients with a daily intake of 100 mg.^[25] Evidence suggests that green tea, in addition to caffeine, contains many other compounds, including the antioxidant epigallocatechin gallate (EGCG), which may be helpful in Parkinson’s as an inhibitor of cell death and alpha-synuclein fibrils,^{[26, 27]} a toxic abnormally folded protein within Lewy bodies, a pathologic sign of the disease. The recommended dose of green tea is three cups per day.

Other nutritional suggestions for patients include foods with high fiber to ease constipation, and colorful fruits and vegetables for their antioxidants. As well, increasing dietary intake of curcumin, a potent antioxidant found in the turmeric spice, has been shown to maintain glutathione in cultured dopaminergic cells.^[28] Glutathione levels are reduced in the substantia nigra of people with early Parkinson’s,^[29] so maintaining a healthy glutathione level would be beneficial. Curcumin has also been found to protect against cell death in cultured dopaminergic cell lines,^[30] as well as reduce alphasynuclein,^[31] both beneficial effects in delaying disease progression.

Integrative Approach

Parkinson’s disease is a chronic progressive neurodegenerative movement disorder for which current medications can only provide symptomatic relief. Levodopa is often helpful in early stages of the disease to manage symptoms; however, it loses its efficacy as the disease progresses because it does not halt the death of dopaminergic neurons. A major challenge in the development of neuroprotective therapies is due to limited understanding of disease processes leading to dopaminergic neurons death. However, there is evidence to suggest that supplemental nutrients can act as neuroprotective and therapeutic agents, to enhance cell functioning and delay disease progression. In addition, exercise in all forms are health-promoting to maintain physical mobility, stability, and strength, while improving mental and emotional well-being in the Parkinson’s patient. Depression is common in Parkinson’s disease, and it is important for doctors to screen for mood disorders, as psychiatric symptoms may decrease quality of life just as much as motor symptoms. Mind-body therapies such as yoga, qi gong, and tai chi are good candidates to be considered in an integrative approach.

When starting any supplemental health program, always ensure that supplements and medications are used safely. An important drug-nutrient interaction to monitor is that pyridoxine (vitamin B6) should be avoided in patients taking carbidopa/levodopa, as it can decrease the efficacy of the medication by increasing the peripheral conversion of levodopa to dopamine before it crosses the blood-brain barrier. As with other chronic degenerative diseases, the cause of Parkinson’s disease is multifactorial, ranging from genetic susceptibilities to toxic exposures, and the balance of these factors will determine whether an individual will develop the disease. While a single cause of the disease is unlikely to be identified, risk reduction can be achieved by maintaining a diet rich in antioxidants and omega-3 fatty acids, engaging in regular aerobic exercise, and reducing exposures to pesticides and heavy metals.