Levodopa is a medicine that is used regularly for Parkinson’s disease (PD). Levodopa is often taken as a combination pill together with carbidopa.

Protein

Levodopa absorption can be affected by how much protein is in your diet, this is because levodopa has a similar structure to the building blocks of proteins called amino acids. The body absorbs proteins and levodopa using the same transporter, so less levodopa is able to be absorbed when it is with protein. This means levodopa levels may be lower when there is more protein in the diet.

• The group of PD patients who benefit most from changing protein in their diet are patients in the later stages of PD and have on-off motor symptoms.
• A low protein diet (LPD) is when protein is limited to a small amount at each meal.
• The protein redistribution diet (PRD) is when the daily amount of protein is eaten in the last meal of the day.
• In studies the protein redistribution diet led to the most improved quality of life for late stage Parkinson’s Disease patients.
• Although reducing protein may benefit some patients' symptoms it is also very important to balance this against potential weight loss and decreased quality of life, if diet is used long term.

Pyridoxine (vitamin B6)

When oral levodopa is taken with pyridoxine (vitamin B6) it can decrease levodopa’s effectiveness.

• Vitamin B6 does NOT affect the combination medication of levodopa and carbidopa, only if levodopa is taken on its own.
• If you are taking levodopa (without carbidopa) you should avoid pyridoxine supplements unless prescribed by your doctor.
• Some foods have high levels of vitamin B6 so discuss with your doctor whether you need to limit your intake of these foods.
• Some examples of high vitamin B6 foods are fish, avocados, bananas, beef, cabbage, carrots, cauliflower, chicken, hazel nuts, peanuts, pork, sweetcorn, vegemite and walnuts.

General Nutrition

Studies show that a good diet containing a high amount of fruit, vegetables and fish reduces the risk of PD and may slow the progression of PD.
Coffee and tea have been reported in studies to be protective of brain cells and reduces risk of PD.

Bottom line:

• When on levodopa it is important to eat a good, well-balanced diet.
• If taking oral levodopa (without carbidopa) you should avoid vitamin B6 supplements unless recommended by your health professional.
• Patients with late stage Parkinson's disease, who have on-off motor symptoms, may benefit from protein redistribution diet. Before changing to a protein redistribution diet should be discussed with your doctor. long term this may lead to weight loss so should be discussed with your doctor.