Several medications can be prescribed to control the symptoms of Parkinson’s disease. It is often recommended that these medications be taken 30 minutes to an hour before meals, but the reason for this recommendation is often unknown. Several nutrients interact with some medications, which may even interfere with their effectiveness. In moderate amounts, these foods are often harmless. Rather, when ingested in large or excessive amounts, they can cause changes in the absorption of the medication and even significant fluctuations in your symptoms. Here are six foods and nutrients that may affect the effectiveness of your medication. Before making any changes in your eating habits, consult your doctor or neurologist.
Proteins
Proteins are mainly found in meat, fish, eggs, cheese, yogurt, nuts and legumes. These compete with levodopa (i.e. sinemet, sinemet CR, stalevo, duopa, levodopa/carbidopa, inbrija, parcopa, rytary) since they are absorbed in the same part of the intestine and use the same transporter to the brain. Therefore, it is possible that the levodopa is absorbed less, and therefore you may feel less its effect or have a slower onset of effect when protein is consumed at the same time as your medication. It is important to note that you should not stop eating foods that contain protein, as it is essential for the proper functioning of your body’s cells. If you experience fluctuations in your symptoms, talk to your doctor about the possibility of :
1- taking your medication more than an hour before meals,
2- eating most of your protein in the evening (fluctuations will have less impact on your active time of day)
3- dividing your protein intake into small amounts throughout the day.
Soft Drinks
Soft drinks are to be banned as they contain artificial sweeteners, such as aspartame, which are used for their ability to sweeten without increasing the number of calories. Aspartame is mainly present in so-called light or sugar-free soft drinks, as well as in other foods such as candies, cereals, some yogurts and other drinks (flavoured waters, iced tea, fruit juice). Once in the intestine, aspartame is metabolised into smaller molecules, including phenylalanine. This molecule competes with levodopa to be absorbed by the intestine and interferes with the transport of dopamine in the brain. This increases the time it takes for your medication to be effective and reduces the ability of neurons to release dopamine. It is therefore advised that you do not consume soft drinks or any other food containing aspartame while taking your medication.
Vitamin B6
Pyridoxine, also known as vitamin B6, is an essential nutrient for a healthy diet. However, too much pyridoxine would reduce the activity of levodopa when given alone (i.e. not in combination with carbidopa). This is rare and mainly concerns the drug Prolopa, which consists of levodopa and benserazide. Vitamin B6 is found in fatty fish (tuna, salmon, cod), offal, poultry, chickpeas, potatoes, bananas, peanuts and whole grain cereals. This adverse effect seems to occur when 50mg and more of vitamin B6 is consumed daily, whereas the recommended daily intake is 1.5mg for women and 1.7mg for men per day for people over 50 years of age. Thus, the harmful dose requires a very large ingestion of vitamin B6, which could be reached if you take supplements of this vitamin or if you eat the foods mentioned above in very large quantities.
Iron
It seems that iron can bind with levodopa and thus reduce the amount absorbed. This would only happen if very high amounts of iron are present in your digestive system at the same time as your medications. This is especially true for people who need to take iron supplements due to another medical condition such as anemia, endometriosis, or inability to absorb iron (e.g., celiac disease or gastric bypass). So, if you are taking iron supplements, discuss with your doctor about this possible drug interaction and how to balance the amount of iron needed with the impact on your Parkinson’s medications.
Frying
All hard-to-digest foods, especially those high in fat, such as fried foods, creamy sauces, chips and cheese, delay the absorption of medications and can cause fluctuations in your symptoms. Constipation also reduces the effectiveness of medications, so avoid eating foods that cause constipation at the same time as you take your medication.
Tyramine
Tyramine is found in foods such as alcohol, aged cheese, deli meats, fermented cabbage and soy products. If you are taking medication called monoamine oxidase B inhibitors, also known as MAO-B inhibitors, such as rasagiline (Azilect), selegiline (Eldepryl) or safinamide (Onstryv), it is recommended that you pay attention to your food intake which contains a very high amount of tyramine (more than 150mg). Indeed, these medications could reduce the effectiveness of your system to break down tyramine, and thus increase the concentrations of tyramine in your body. At very high levels, tyramine can cause severe high blood pressure, which should be taken seriously.
Remember to follow these tips
All in all, the important thing is to have a balanced diet while avoiding excessive intake of the above-mentioned foods. Taking your medication at least 30 to 60 minutes before meals will help reduce possible food and drug interactions. Before making any significant changes to your diet, it is imperative to discuss them with your doctor or nutritionist.
Alexandra Potvin-Desrochers, Doctorante