Description:

Parkinson's Disease (PD) was first described by Dr. James Parkinson, an English Physician, in an 1817 scientific paper entitled, "The Shaking Palsy". Since then, scientists have discovered that in the normally functioning brain, the substantial nigra (a part of the midbrain that regulates muscle movement) produces dopamine, a neurotransmitter that allows for communication between the neurons in different parts of the brain. In patients with PD, there is a gradual loss of the nerve cells that produce dopamine. Without dopamine, the body becomes greatly incapacitated in motor activities, which affects many aspects of activity such as walking, talking, eating, etc. Diagnosis of the disease is by neurological examination, preferably done by a neurologist specializing in movement disorders, as there is no lab test that identifies PD.

Symptoms:

The major symptoms of PD include:

• resting tremor (usually of the hands and head, but can include the feet)
• bradykinesia (slow movement)
• rigidity of limbs
• impaired balance

Other symptoms include a mask-like facial expression, shuffling gait, stooped posture, difficulty swallowing, drooling, constipation, dandruff, oily skin, urination difficulty, sexual dysfunction, sleep disturbances, depression, dementia, small/cramped handwriting, lack of arm swing, and freezing episodes (feeling as if unable to move when trying to walk). PD patients often speak in a soft voice, and speech can take on a monotonous tone. Most individuals do not experience all of the above symptoms and the severity of symptoms varies from patient to patient.

Progression of the Disease:

PD is a chronic, slowly progressive disease that can be disabling within 5 to 20 years but is not fatal. For many PD patients, the first sign of the disease is a tremor of the hand on one side of the body. Bradykinesia, as well as rigidity, may slowly set in on the affected side. Eventually, symptoms may progress to the unaffected side of the body as well and balance may be impaired. In later stages of the disease some patients may be confined to a wheelchair or bed-ridden.

Prevalence (number of diagnosed cases) and Incidence (number of new cases): PD affects approximately 1 to 1.5 million people in the USA, with 50,000 new cases being diagnosed each year. The disease usually begins between the ages of 40 and 70, with an average age of onset in the late 50s or early 60s. However, PD can occur at any age as 5-10% of patients are younger than 40. PD affects 1% of the population in the United States of those over 50 years of age. PD occurs almost equally in men and women and some studies have shown a lower incidence in African Americans and Asians compared to Caucasians.

Cause:

The cause of PD (which is not contagious) is unknown, yet environmental factors, such as exposure to pollution, pesticides, etc., are thought to play a role. Oxidative damage from free radicals and the aging process may also be factors. Damage to dopamine-producing cells in the substantia nigra may be a result of an excess of free radicals or the loss of ability of the body to inactivate the free radicals. Healthy individuals make enzymes that help to neutralize free radicals, however, these enzymes may be depleted in the brains of persons with PD. Free radicals damage other molecules by stealing electrons and setting off chain reactions that can result in cellular damage. Other possible factors presently being studied include vitamin E deficiency, environmental manganese exposure, and zinc deficiency.

TREATMENT:

Medicine:

• Levodopa (L-dopa) is the most widely used medication for PD. Dopamine cannot cross the blood-brain barrier, so it is not administered to patients. Instead, the precursor to dopamine, L-dopa, is used to treat the symptoms of the disease. L-dopa is usually more effective in reducing bradykinesia and rigidity compared to tremors. As there are side effects to the medication, treatment decisions must consider improved performance as well as side effects that can include dyskinesias (abrupt jerking movements), nausea, confusion and dizziness. L-dopa is usually combined with carbidopa (Sinemet) to improve performance and decrease side effects. The medication can be very effective for a period of 2-5 years and then may start to "wear off". Some patients also experience an "on-off" effect in later stages of PD. To prevent this wearing off, patients may need to take doses more frequently, change to a controlled release form of the drug or include a dopamine agonist, selegiline or COMT inhibitor as part of their treatment (see below). L-dopa is effective for approximately 75% of patients. The rate of gastric emptying can influence the effectiveness of L-dopa, thus medication should be taken on an empty stomach, at least 30 to 60 minutes before eating.
  
  
• Anticholinergics are given to patients to reduce tremors. Side effects include constipation, dry mouth, bladder elimination problems, confusion and blurred vision.
  
  
• Amantadine is an antiviral medication used alone or in conjunction with L-dopa (Sinemet). Side effects include skin discoloration, confusion and depression.
  
  
• Selegiline is given in conjunction with L-dopa (Sinemet) or alone, usually as a precursor to L-dopa therapy. Side effects include stomach upset and insomnia.
  
  
• Dopamine Agonists are drugs that mimic dopamine activity. These are usually given in conjunction with L-dopa (Sinemet) or alone, before initiation of L-dopa therapy. Side effects include nausea, nightmares and hallucinations.
  
  
• Catechol-O-methyltransferase (COMT) Inhibitors inhibit an enzyme that breaks down dopamine and are taken in conjunction with L-dopa (Sinemet). Side effects include increased involuntary movement and diarrhea.
  
  

Surgical Procedures:

Surgical procedures are primarily for patients who have been on medication for an extended period of time. Drug therapy has either become less effective or the patient may be experiencing severe side effects.

• Pallidotomy is a procedure that can diminish the uncontrollable movements, which are a side effect of long-term use of L-dopa (Sinemet). Magnetic imaging is utilized to locate cells in the area of the brain called the globus pallidus. It is believed that increased activity in this area is the cause for dyskinesias (jerking arm and leg movements). A thin electrode is placed in this area on one side of the brain to destroy these cells. This allows patients to continue using medication. Only a small percentage of patients are candidates for this procedure. Those that are ruled out include patients whose main symptom is tremor, those that are very old, have dementia or are at a very late stage of PD. Pallidotomy does carry the risk of neurological complications in about 15% of patients though serious side effects occur in less than 2% of patients. Complications include stroke, partial loss of vision, confusion and speech/swallowing problems. Long term effectiveness of the procedure is not known.
  
  
• Thalamotomy is similar to pallidotomy (see above). Cells that are destroyed are located in the thalamus. This procedure is utilized for patients experiencing severe tremors.
  
  
• Deep Brain Stimulation by Electrode Implant is a procedure in which an electrode is surgically placed in the brain and is connected to a device similar to a pacemaker implanted in the collarbone area that the patient can switch on and off as symptoms occur.

Experimental Surgical Procedures:

• Fetal Tissue Transplantation is still in the experimental stage and involves the grafting of dopamine-producing fetal tissue into the brains of PD patients. Some patients have shown improvement of symptoms, thus allowing them to decrease their medication. Other experimental therapies include genetic engineering and the administration of neuroprotective agents.

DIETARY ISSUES RELATED TO PD:

• Constipation is one of the most common complaints of PD patients. To avoid this, patients should increase the amount of fiber in their diet by eating high fiber foods such as fruits, vegetables, whole grains and legumes (pinto or black beans). At least 20-25 grams of fiber should be consumed daily, and intake should be increased gradually. It is important to consume adequate amounts of water (earlier in the day to avoid getting up at night to urinate) and get plenty of exercise. If consuming more fiber-rich foods does not alleviate the problem, psyllium or prunes/prune juice can be added to the diet. Laxatives should be used only as a last resort.
  
  
• Impaired Bladder Emptying from dehydration and the inability to completely empty the bladder can lead to an increase in urinary tract infections (UTIs). Studies have shown that drinking a glass of cranberry juice each day, along with plenty of water, can diminish the risk of UTIs.
  
  
• Difficulty Eating/Swallowing: As the disease progresses, patients may have difficulty feeding themselves due to tremor or muscle rigidity, as well as problems swallowing food. Patients should try and eat softer, moister foods, and avoid foods that are more difficult to chew or are hard to manipulate. A speech therapist can also be of assistance.
  
  
• Dry Mouth can be relieved by chewing gum, sucking on hard candy or ice, and sipping water during the day. Some say to avoid alcohol, caffeinated drinks and tobacco.
  
  
• Weight Loss is common in patients who have had PD for some time, due to both symptoms of the illness and side effects from the medication. Problems contributing to weight loss include: nausea, appetite loss, decreased sensitivity to smell, dry mouth, tremor, problems swallowing, dyskinesias, bradykinesia, and depression. Solutions to weight loss include:
  • eating several smaller meals instead of three large meals a day
  • switching to foods that are softer and easier to chew/swallow
  • consuming calories in food supplement form, such as fortified smoothies or snacks
  • eating a few bites of a cracker or pretzel when taking medication to reduce nausea.
  
  
• Weight Gain can occur in early PD due to inactivity and depression. Patients should adhere to a balanced diet that is lower in calories and low in fat, along with an exercise program to help shed the extra pounds.
  
  
• Osteoporosis can occur in PD patients that are elderly, and thus at greater risk for osteoporosis, especially if milk products are decreased in order to limit protein intake (see below). PD patients should consume enough calcium and vitamin D. Natural sources of calcium include milk products (choose low fat varieties), dark green leafy vegetables, broccoli, soybeans and many fortified foods. The recommended daily intake for calcium is 1,500 mg and for vitamin D is 800 IU. Natural sources of vitamin D are fortified milk and fatty fish. Exposure to sunlight is also a good source.

FOOD/NUTRIENT CONSIDERATIONS:

• Vitamin B6 (pyridoxine). The combination form of L-dopa (Sinemet), which is the most commonly prescribed type of medication, is not affected by vitamin B6 intake. However, this vitamin can decrease the effectiveness of L-dopa if the medication is taken without carbidopa (see above). Food sources of vitamin B6 include yeast, wheat germ, whole-grains, legumes, bananas, potatoes, pork and liver.
  
  
• Fava Beans (Broad Beans) are a source of natural L-dopa and some PD patients have reported therapeutic benefits from including these beans in their diet. In one small study, five out of six patients who consumer fava bean pods showed motor improvement. A 100 gram serving of fava bean pods contains approximately 250 mg of L-dopa (most of the L-dopa is found in the pods rather than bean). The researchers of the study suggest consuming fava beans/pods, which are high in protein, as a substitute for other sources of protein in the diet, in addition to taking their L-dopa medication. Including fava beans / pods in the diet may be beneficial, however, patients should be aware that large amounts may cause some of the same side effects of taking higher doses of dopamine.
  
  
• Iron supplements have been shown in some cases to reduce effectiveness of some PD medications. Thus, iron supplements, if necessary, should not be taken at the same time as prescription drugs.

NUTRITIONAL RECOMMENDATIONS:

General Recommendations are that patients should consume a healthy diet that is low in fat, especially saturated fat, low in cholesterol and high in whole grains, fruits and vegetables, ensuring an adequate fiber intake. Excessive caffeine consumption should be avoided as it can interfere with calcium absorption. Alcohol consumption should be limited as alcohol can have an adverse effect on certain medications and can cause an increased risk for developing certain cancers. PD patients that experience symptoms that compromise nutrient intake can compensate by consuming fortified foods or a daily multivitamin/mineral supplement.

Antioxidants: Since the progression of PD may involve free radicals (see above), the consumption of antioxidants may be helpful as antioxidants are electron donors and thus can stop the chain reaction of free radical damage. Patients, as well as healthy individuals, might want to consider a daily dose of the following antioxidants:

• Vitamin C, 500mg, found in citrus fruits, raw leafy vegetables, tomatoes, strawberries, cantaloupe, cabbage and green peppers.
  
  
• Vitamin E, 400IU, found in wheat germ, corn, soybean and sunflower oils and avocados. Though some think large doses of vitamin E may slow progression of the disease, recent studies have found no evidence of benefit from vitamin E. Even so, many doctors do recommend that their patients consume at least 400IU of vitamin E per day. Patients who are taking anticoagulant drugs should check with their doctors before consuming supplemental vitamin E.
  
  
• Mixed beta-carotenes, up to 15,000 IU, found in dark green leafy and yellow-orange vegetables and fruits.
  
  
• Selenium, 150mcg, found in brazil nuts, seafood and poultry.

Visit our Home Nutrition Store to place an order.

Water: it is extremely important for PD patients to drink plenty of fluids to avoid dehydration.

Protein Restricted or Redistributed Diet: In a small number of PD patients (primarily those experiencing the on/off effect), L-dopa effectiveness can be compromised by the ingestion of some amino acids, the building blocks of proteins. The large neutral amino acids (LNAAs) compete with L-dopa at both the level of absorption from the gastrointestinal tract as well as at the blood-brain barrier. This diet consists of restricting total protein to only the recommended daily protein intake. To calculate your personal protein needs, multiply 0.8 times your weight in kilograms (to find kilograms, just divide your weight in pounds by 2.2) which will give you the total number of grams of protein per day. The protein allotment is consumed mostly at dinner, with only 8-10 grams of protein allowed at breakfast and lunch combined (or before 5pm). This allows for improvement of symptoms during the daytime, but increased rigidity at night. High protein foods include meat, fish, poultry, eggs, milk products, legumes, nuts, and whole grains. Low protein foods include most fruits and vegetables. Many patients find that the protein redistribution is not necessary and that eating meals 30 to 60 minutes after taking their medication is enough to avoid interference. Improvement with this diet should be evident within a few days.

As an alternative to protein redistribution, some PD patients prefer a diet based on a certain carbohydrate/protein ratio. The most common ratio used consists of consuming 7 grams of carbohydrates to every 1 gram of protein at each meal. Patients can also try 5, 6, 8 or 9 to 1 ratios to see which works best for them.

• DHEA stands for dehydroepiandrosterone, a male hormone. Dietary supplements of DHEA are made from extracts of wild Mexican yam. Claims that DHEA can ward off PD are unfounded. The FDA banned the sale of DHEA as an over-the-counter drug in 1985 but since 1994, under new laws, DHEA can be sold as a dietary supplement and does not require FDA approval. Even though DHEA is a supplement that can be bought without a prescription, most doctors advise patients against self-medicating since not enough is known about DHEA and its side effects at the present time. Side effects include possible masculinization and menstrual problems in women, and aggravation of prostate enlargement or even prostate cancer in men
• Coenzyme Q10 is another dietary supplement that has been mentioned to have benefits for PD patients. However, even though studies are underway, there is presently no scientific data that prove any beneficial effects for those who have PD.

Patients with PD may benefit from physical therapy, occupational therapy, speech therapy, counseling, support groups, stress reduction, and exercise. Parkinson's disease should be closely followed by a doctor. Any nutritional recommendations contained in this article should be discussed with the patient's physician and preferably a dietitian.

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