Parkinson's Disease and Vitamins

How can Vitamins help with Parkinson Disease?
By: Dr. Obikoya

Parkinson's disease (PD) is a common neurodegenerative movement disorder that is associated with significant medical disability, reduction in quality of life, and, in advanced stages, caregiver burden. Approximately 0.5-1.0 million individuals in the United States have been diagnosed with PD, most falling within the age range of 55 to 60 years at time of diagnosis.

With the increase of the senior population in the United States, the prevalence of PD is expected to rise. In response to this anticipated increase in the prevalence of PD, the search for agents that may delay or arrest its pathologic progression (i.e., neuroprotective agents) has become a high priority among researchers.

Neuroprotection is defined as protecting neurons from cellular damage induced by various biochemical insults associated with the pathogenesis of PD.

Parkinson’s disease is caused by deterioration of nerve cells in the basal ganglia, the part of the brain responsible for muscle movement. As less dopamine (which is used by neural transmitters) is produced, muscle function is lost. Symptoms of Parkinson’s include unstable balance, slow movement, difficulty walking, muscle stiffness or rigidity, difficulty initiating movement, muscle tremors, muscle ache, and speech changes.

A growing percentage of the U.S. population is turning to nutritional supplements in the hope of improving general health and well-being. It's no surprise, then, that more and more people with PD are asking whether vitamins or other supplements could benefit Parkinson's disease (PD) itself.

Also referred to as "CoQ10," this compound is a dietary supplement that is widely available. In a recent phase 2 study, high doses of CoQ10 (1200 mg per day) demonstrated symptomatic benefits in patients with early PD.[1] The putative neuroprotective activity of CoQ10 may be due to its antioxidant properties and enhancement of the mitochondrial complex I activity (which may be defective in PD). Of note, the CoQ10 product used in the study also contained significant amounts of vitamin E, another known antioxidant. The possible influence of vitamin E on the results of this study was not evaluated. However, in a previous clinical study (DATATOP), high-dose vitamin E (up to 2000 IU per day) was not associated with clinical symptomatic or neuroprotective benefits.[2]

Many individuals with PD already use vitamins in addition to the medications their doctors gave them to treat the condition. Interest in studying the effects of vitamins on PD is growing among medical researchers. Indeed, research findings suggest that certain vitamins help improve balance in PD. In addition, several vitamins and other nutritional supplements are now being actively studied in the laboratory or in clinical trials to determine whether they have a role to play in treatment of PD.

No intervention is currently known for certain to slow down the progression of PD, but recent research suggests that one potential means to this might be found in modifying nerve cell metabolism. Most cells in our body contain "energy generators" called mitochondria; their function is vital, and the brain in particular uses high amounts of energy. Researchers think that deficiencies in the functioning of mitochondria may play a role in PD, raising the question as to whether changing the energy balance in nerve cells could be protective. One compound that has attracted a lot of attention lately in this connection is Coenzyme Q10 (CoQ10), a common nutritional supplement. CoQ10 plays an important role in the mitochondria and is also a potent antioxidant.

In a recent phase 2 study, high doses of CoQ10 (1200 mg per day) demonstrated symptomatic benefits in patients with early PD.1 The putative neuroprotective activity of CoQ10 may be due to its antioxidant properties and enhancement of the mitochondrial complex I activity (which may be defective in PD). Of note, the CoQ10 product used in the study also contained significant amounts of vitamin E, another known antioxidant.

The possible influence of vitamin E on the results of this study was not evaluated in the study. However, in a previous clinical study (DATATOP), high-dose vitamin E (up to 2000 IU per day) was not associated with clinical symptomatic or neuroprotective benefits.2

Another supplement that likely acts through its effects on energy metabolism and could be useful in Parkinson's is creatine. This compound increases levels of phosphocreatine, an energy source in the muscle and brain, and in experimental studies it protects against nerve cell injury.

The National Institute of Neurological Disorders and Stroke (NINDS) has now funded a multi-center pilot study of creatine (along with another agent, minocycline) in PD patients who have not yet taken any medicines for their PD. The supplement has few reported side effects. Glutathione, a compound with multiple effects on nerve cell metabolism as well as a powerful antioxidant, is of particular interest for PD because of studies showing its depletion in the substantia nigra (the site of major nerve cell damage in PD).

Other supplements at earlier stages of investigation in the laboratory include nicotinamide, riboflavin, acetyl carnitine and lipoic acid.

Based on strong evidence linking oxidative damage of nerve cells to PD, there has been much hope that antioxidants could play a role in slowing the progression of the disease. Besides CoQ10 many PD patients take antioxidants such as vitamin E or vitamin C. Vitamin E can combat the damage caused by free radicals. Some have reported that high dietary intake of vitamin E lowers the risk of PD, although a rigorous trial of a decade ago- the DATATOP study – mentioned earlier found no evidence that even high doses of vitamin E (up to 2000 IU per day) had any effect on progression or symptoms of PD.

So, what's the bottom-line? For people who are interested in exploring complimentary approaches to easing PD, there does seem to be increasing scientific evidence of the efficacy of some available supplements, but safety has to come first. For example, patients with Parkinson’s Disease should not take iron supplements, as they appear to increase the rate at which the disease progresses.

Treatment for Parkinson’s disease is geared toward controlling symptoms. This can be done using medication that enhances neural transmitters or helps to mask disease symptoms. It is reasonable to explore supplementing this treatment with those vitamins of proven effect on PD.

References:
1.Shults CW, Oakes D, Kieburtz K, et al. Parkinson Study Group. Effects of coenzyme Q10 in early Parkinson disease: evidence of slowing of the functional decline. Arch Neurol. 2002;59:1541-1550.

2. Parkinson Study Group. Effects of tocopherol and deprenyl on the progression of disability in early Parkinson's disease. N Engl J Med. 1993;328:176-183.