Primary Nutritional Issues with Parkinson's Disease

Parkinson's disease is a progressive, disabling, neurodegenerative disease resulting from a decreased production of dopamine. It affects an estimated 1.1 million Americans. The main treatments for managing this disease are prescription drugs, such as levodopa and monoamine oxidase inhibitors (MAOIs), surgical interventions and physical and occupational therapy.

As the disease and its symptoms progress, patients with Parkinson's disease can have trouble walking, talking or doing everyday tasks. Issues such as difficulty chewing and swallowing, excessive salivation and decreased gastric motility may be experienced. In addition, medication-related side effects such as dry mouth, nausea, vomiting, appetite loss and anorexia can alter food intake and result in unintentional weight loss.

For individuals with Parkinson’s, nutritional goals may include improving fiber intake and hydration status to address constipation, which is a common symptom with the disease. Dysphagia and gastrointestinal problems, such as gastroparesis or gastroesophageal reflux disease, can influence nutrition interventions. Providing adequate energy to prevent unintentional weight loss or excessive gains is especially important for individuals with Parkinson's disease.

For patients who are taking levodopa, amino acids in protein can interfere with the medication. Modifying the timing of protein intake, so that a larger amount is consumed in the evening, may help to minimize its interaction with this medication. Appropriate planning is needed to make sure protein needs are still met each day. An alternative option would be to alter the carbohydrate to protein ratio with meals. If a patient with Parkinson’s disease is not on levodopa, however, they do not need to limit their protein intake.

In addition to levodopa, individuals taking MAOIs also require modified diets. Individuals who are prescribed MAOIs may need to limit foods and beverages that contain tyramine, such as aged meats and cheeses.

For patients with Parkinson’s, supplementation of vitamin D and B12 may be warranted. However, there are concerns regarding supplements that provide more than 100% of the Daily Value for iron and manganese, as well as the timing of vitamin B6 for those taking levodopa.

Research studies using diet or supplement regimens to prevent or treat Parkinson's disease have been inconclusive. While there is currently no scientific evidence that any specific dietary factor is beneficial, a general, healthful eating plan can promote overall well-being for people with Parkinson's disease. Registered dietitian nutritionists working with patients who have Parkinson's disease will need to individualize the nutrition intervention based on a review of the patient's symptoms and reassess the nutrition care plan as the disease progresses to meet the individual's health needs.

References:

• Academy of Nutrition and Dietetics. Nutrition Care Manual^®. Parkinson's Disease. Accessed April 9, 2026.
• Escott-Stump S. Nutrition and Diagnosis-Related Care, 9th ed, Chicago, IL: Academy of Nutrition and Dietetics; 2021.
• Mahan KL, Escott-Stump S, Raymond JL. Krause's Food & Nutrition Therapy, 14th ed. St Louis, MO: Elsevier Saunders; 2017.