PARKINSON’S DISEASE
PARKINSON’S DISEASE
Also known as shaking palsy, Parkinson’s disease is one of North America’s most common debilitating illnesses. It is often thought of as a disease of old age – one person in a hundred will develop it by retirement age, but half of them may have it by age 40.
Parkinson’s disease develops progressively. Nerve cells slowly degenerate in the part of the mid-brain that controls movement (the substantia nigra layer of the basal ganglia). In normal health, messages from the motor cortex to the reticular formation initiate free movement, and neurotransmitters released from the basal ganglia in response to the same messages slow or dampen movement, providing the suppleness and dexterity we take for granted. These two neurotransmitters are dopamine, which stimulates the damping effects, and acetylcholine, which inhibits it.
SYMPTOMS AND CAUSES
Its exact cause is usually unknown, but Parkinson’s disease is characterized by cell damage in the basal ganglia. Production of dopamine slows down and the characteristic symptoms appear. It begins with weakness or stiffness accompanied by a slight tremor of the hands or head. Over time the shaking increases, muscles stiffen further and there is a visible deterioration in balance and coordination. In advanced stages, symptoms include generalized rigidity, drooling, loss of appetite, stooped posture, a shuffling walk and a fixed facial expression. Eventually, communication skills may be impaired. Dementia, depression and other emotional problems are common.
Genetic factors play a role too, but there are other contributing causes including certain medications, pesticides, carbon monoxide, cyanide, manganese, street heroin, specific viruses and the type of repetitive head trauma suffered by boxer Mohammed Ali (dementia pugilistica). Researchers at the National Institute of Health in Bethesda have recently identified a gene programmed for the production of a protein called alpha synuclein. There is hope that this clued will open the door to further discoveries about Parkinson’s disease and innovative ways to treat it.
TREATMENT
There is so far no definite cure for Parkinson’s disease but it is treatable – most effectively at its outset. Therefore, early diagnosis is best. For the time being, conventional treatments include medication that attempts to restore neurochemical balance by replacing or supplementing the body’s production of dopamine. Neurosurgical techniques and fetal tissue implants have had some success. Some scientists are developing implantable electrodes into the brain to stimulate specific neural pathways. Drugs such as selegiline have shown promise. A team headed by researchers P. Jenner and C.W. Olanow from the Neurodegenerative Disease Research Centre in London have shown that selegiline may increase GSH activity. Recently, newer drugs like pramipexole and ropenerole have emerged as more effective treatments.
PARKINSON’S DISEASE AND GLUTATHIONE
Recent research has revealed two important findings: first, biochemical analysis of the affected brain tissue shows damage consistent with extensive oxidative stress and the circulation of free radicals that follows it; second, GSH levels in these tissues are particularly low. A striking feature of Parkinson’s is an approximate 40% decrease during the early stages of the disease. A group of researchers from the University of Southern California led by J.D. Adams Jr. were able to show that in advanced Parkinson’s Disease glutathione levels fall to a mere 2% of normal. Whether the drop in GSH is a cause or a symptom of this damage remains unclear. But there is good news – elevated GSH levels slow brain tissue damage. Some symptoms may even be reversed.
Since damage caused by free radicals is an invariable component of Parkinson’s Disease, researchers have experimented with a variety of high-dose antioxidants. In addition to the more well-known antioxidants, glutathione therapy has also been used. Not only is GSH an exceptional antioxidant, the substantia nigra of Parkinson’s patients is especially deficient in it, so their need is particularly great. M. Gabby’s research team in Israel showed that elevated GSH levels more effectively reduce dopaminergic toxicity than the antioxidant vitamins C and E. Paradoxically, while brain cells need dopamine to function, dopamine at certain times is actually toxic to the same tissues. This may be why drugs which raise L-dopa levels, like Sinemet, only work for a few years before the effects wear off and the patient subsequently deteriorates.
Dr. P. Jenner and his team at the Parkinson’s Disease Experimental Research Laboratories in London have extensively examined the role of GSH in the progression of this disease. They found that glutathione levels fall consistently at the onset of Parkinson’s Disease and believe that elevated GSH levels can help prevent neural damage.
D. Offen’s team at the Beilinson Medical Center in Israel experimented on the actual neurons involved in dopamine metabolism. They investigated the cell-death associated with the Parkinsonian decline in dopamine. To slow down this decline they used antioxidants, and found that the thiol (sulfur-containing) antioxidants GSH, NAC and dithioleitol worked well. In the cautious language of medical science, they described them as “markedly protective” of brain cells. This corroborated the findings of M. Gabby’s work (above), further supporting the theory that GSH may prevent or delay dopamine-induced cell death.
G. Sechi and his team in Italy studied a group of untreated Parkinson’s patients in the early stages of the disease who received intravenous GSH therapy twice a day for a month. All patients improved significantly with more than 40% decrease in their disability. The improvement faded away two to four months after the last GSH treatment.
“Other authors have drawn attention to the role of GSH-enhancing drugs in the treatment of this disease. There is much evidence to support the usefulness of elevated glutathione levels. Today, however, there are ways to raise GSH levels without the use of pharmaceutical drugs.
CASE STUDY
Glutathione is part of the body’s defense system and protects us against the onset of many disease processes. It can also help to reverse certain conditions or symptoms, either temporarily or permanently. The following story illustrates the apparent helpfulness of GSH supplementation in one particular case.
Wally, a seventy-four year-old baseball fan, was diagnosed with Parkinson’s disease in May 1997. His disease progressed quickly and his doctors placed him on Sinemet (carbidopa/levodopa). In November he began to experience severe headaches – presumably from the medication – and he discontinued it. Up to this point he had been a very active man, but now he deteriorated to the point where he could not get out of bed or even rise from a chair without help. He says movement felt like ‘walking in cement’. He was constantly fatigued and soon needed a wheelchair to go outdoors. The doctors used other medications including Eldepryl (selegiline hydrochloride) and Requip (ropinirole hydrochloride). They helped slightly. In March 1998 he started taking Immunocal, a natural protein which raises GSH levels. After five days his headaches were gone. Within two weeks his fatigue had lessened. Two months later Wally was walking well again and was eventually able to visit the new Angels
baseball stadium, Edison Field, and job around the block. There was no other therapeutic intervention and seven months later his active lifestyle continued.
62 year-old Carol maintained an active legal practice until 1990. After a diagnosis of Parkinson’s disease in 1986, she was able for a while to continue her career as a lawyer, but eventually had to quit. The stress was aggravating her symptoms and the symptoms were in turn increasing her stress levels. She was treated with a number of different medications but her health continue to deteriorate until she eventually needed help at home to carry out day-to-day tasks. She quit driving her car and stopped taking her daily walks, which she loved. Then, within days of starting to take a bioactive whey protein isolate she noticed her strength returning. Weeks afterwards she was once more exploring her neighborhood and nine months later she was driving again.
CONCLUSION
Parkinson’s disease is characterized by a loss of the brain cells that regulate dopamine. Significant evidence points to the role of oxidative stress and dramatically low GSH levels as critical contributing causes of this damage. Studies have demonstrated that protecting these cells from damage and death by raising GSH levels can succeed both in the laboratory and in patients and is a welcome addition to conventional medical treatments.
REFERENCES TO PARKINSON’S DISEASE
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SIAN J, DEXTER DT, LEES AJ, DANIEL S, AGID Y, JAVOY-AGID F, JENNER P, MARSDEN CD. Alterations in glutathion levels in Parkinson’s disease and other neurodegenerative disorders affecting basal ganglia. Annals of Neurology 36(3): 348-355, 1994
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