Dietary advice tips: (10) Parkinson's disease
Parkinson's disease is a progressive neurological disorder affecting learned voluntary movements such as walking, writing, swallowing and talking. The main symptoms are tremor, rigidity and slowness of movement. In the United Kingdom, Parkinson's disease affects one in 500 people, with a prevalence of one in 100 in people over 60 and one in 50 in people over 80. The main treatment is drug therapy and there is little evidence that any specific mineral, vitamin or other nutrient can prevent or treat the disease. However, nutritional advice can help to improve the patient's quality of life.
- Eating a healthy diet with regular meals is important for patients with Parkinson's disease because it helps digestion and the absorption of medication. A normal, balanced diet should therefore be encouraged.
- Many patients with Parkinson's disease suffer from constipation, which may be caused by their drug therapy. A high fibre diet, containing plenty of wholemeal bread, cereals, vegetables (especially peas and beans) and fresh and dried fruit should be encouraged.
- Many patients have problems with a dry mouth (often caused by medication) and swallowing difficulties. For these patients, food consistency is an important consideration. Soft, moist food such as custard, sauces, soup and yoghurt tend to be easier to swallow, but it is important to try to exercise the jaw too, so soft food should not be eaten to the exclusion of everything else.
- Foods that stick to the roof of the mouth, such as fresh bread, dry mashed potato and tomato, may be a problem for some patients.
- Some patients may have difficulty in handling cutlery and cutting up their food. Special cutlery can be obtained, and food can be cut into small pieces for the patient, but other measures, such as eating peas or rice with a spoon, can be helpful.
- If the patient eats slowly, family and friends should be encouraged to continue conversation at mealtimes to allow the patient to finish their food.
- Some patients have difficulty consuming sufficient calories to maintain their body weight. Additional calories can be obtained by eating fatty and sugary food or by adding, for example, cream to soup, butter or margarine to vegetables, or grated cheese to soup.
- Food supplements such as Complan, Ensure and other "milk shake"-type drinks, and blancmange-type puddings such as Formance and Fortipudding are helpful for patients who require more calories.
- If tremor is severe, a sip feed with a straw may be the easiest type of food to handle.
- The use of vitamin supplements remains controversial, but a multivitamin supplement may be helpful for a patient who is not eating well.
- In some studies, vitamin E, vitamin C and selenium have been shown to slow the progress of Parkinson's disease, but further research is required.
- Supplements containing vitamin B6 should be avoided by patients taking levodopa. However, levodopa is now rarely used on its own and this advice does not apply to patients taking levodopa combinations such as co-beneldopa and co-careldopa.
- Protein can interfere with the absorption of levodopa (including that from combination preparations), and restriction of protein intake may help to maximise the effect of levodopa. However, a dietitian should advise on the reduction of protein and how protein intake should be spread throughout the day. If this intervention works, and a suitable pattern of meals and drug administration is established, variation in eating habits should then be avoided as this may reduce the effect of levodopa and lead to clinical deterioration.
This series of "dietary advice tips" is intended to be a reminder of the main points to be made by pharmacists when giving nutritional information to the public. The conditions included in the series are those where diet is a well recognised risk factor, those in which diet contributes to the management of the condition, and others for which patients may welcome sound dietary advice. The series is written by Dr Pamela Mason (a pharmacist with a postgraduate qualification in nutrition)