Nutritional Issues in Parkinson's Disease
by Michael Rezak, MD, PhD
Nutritional status is a major factor influencing the well being of any individual who lives with a chronic neurological disease. Nowhere is this truer than for those dealing with Parkinson's disease (PD). Poor nutritional status can result in, as well as contribute to, many of the common complaints seen in Parkinson's disease. For example, in those individuals with swallowing problems the effects of malnutrition become magnified. It may ultimately lead to worsening motor symptoms, increased weakness resulting in falls and possibly serious bone fractures. Thus, it is incumbent upon the physician taking care of those with PD to pay close attention to nutritional status and to seek assistance from dietetic professionals whenever necessary. Simple measures used to assess nutritional status include taking the patient's weight at each visit and utilizing various blood and urine tests as well as obtaining a thorough patient history.
Obstacles to proper nutrition which some people with PD may experience include constipation, swallowing and chewing problems, delayed gastric (stomach) emptying, loss of sense of smell and taste, dry mouth, depression, dementia, nausea, and gastroesphageal acid reflux (heartburn). Some of these problems are intrinsic to PD itself, while others are a result of the medications and still others may be related to both. I will attempt to address some of these problems in the paragraphs that follow.
Constipation is a serious and common problem in patients with PD at all stages of the disease. Poor hydration, low dietary fiber and decreased exercise, as well as the medications themselves, combine with the decreased neural function of the gut in PD to create this problem. The constipation can result in a loss ofappetite, complaints of bloating and, if not corrected, can lead to impaction which
can be life threatening. The best treatment is prevention. PD patients should be instructed to increase dietary fiber intake to approximately 25 to 35 grams per day in association with appropriate fluid intake (at least 60-70 oz of water per day). Further recommendations for treatment can be obtained from the dietetic professional and/or gastroenterologist.
Delayed gastric emptying can also be a problem in some PD patients. This results in erratic release of levodopa into the small bowel where absorption of this drug takes place, and thus can contribute to fluctuations. Furthermore, delayed gastric emptying may result in complaints of "heartburn"
(gastroesophageal reflux) which is quite common in PD. When the reflux is combined with nausea (which can be the result of the PD medications), appetite suppression may follow, which can then lead to inadequate caloric intake. There are medications that can counteract this nausea, and many over-the-counter drugs that are available and effective in treating the acid reflux symptoms. The treatment of delayed gastric emptying is a more challenging problem and may necessitate a visit to the gastroenterologist.
Swallowing and chewing problems can be major obstacles to maintaining proper nutrition. The increased time it may take to chew and swallow can contribute to inadequate nutritional intake. Intensive therapy with a speech pathologist can be helpful in learning techniques to improve safety and efficiency of chewing and swallowing. Sometimes a simple change in the consistency of the food can result in significant improvement. However, if inadequate nutritional intake or aspiration issues continue to be a significant problem, consideration must be given to nutritional supplements as well as other treatments or procedures.
Protein sensitivity occurs in some PD patients. When this occurs, the large neutral amino acids in the protein of a meal are favored over levodopa for
absorption, which may then result in motor fluctuations and prolonged "off" episodes. Some patients who experience protein sensitivity may elect to forego protein in their diets; however, this can contribute to a malnourished state if allowed to continue. Solutions to this problem include protein redistribution diets and ingestion of protein late in the evening when motor activity is less important. A knowledgeable dietetic professional can assist with formulating appropriate diet plans to circumvent this problem.
The prophylactic build-up of bone status should be encouraged to prevent bone fractures and their serious complications if falls should occur. Ingestion of dairy products or food sources fortified with vitamins D and K as well as calcium are encouraged. Weight bearing exercises are also known to promote bone health.
Finally, motor symptoms in PD often result in additional expenditures of energy (e.g., tremor, dyskinesia). This combined with inadequate nutritional intake can effect motor functioning and the overall general health of the patient. Nutritional counseling should be an important part of the comprehensive treatment of every PD patient, regardless of the stage of the disease.
Dr. Rezak is the Medical Director of the APDA National Young Onset Center as well as the Director of the Movement Disorders Center and Co-Director of the Deep Brain Stimulation Program of the Neurosciences Institute at Central DuPage Hospital in Winfield, IL. Dr. Rezak is also on the Speaker's Bureau for Allergan, Novartis, Medtronic, Teva, and GlaxoSmithKline.