Richelle Flanagan has been a registered dietitian for the past 19 years, is a wife and mum to two children and has lived with YOPD for six years. Her lived experience has led her to develop My Moves Matter, a digital self-care companion tailored to support and empower women to live well with Parkinson’s. Here she discusses probiotics, protein foods and levodopa absorption, eating dairy and gluten, and reveals what she eats as a PwP

Richelle Flanagan

Should PwPs take probiotics? If so, are any particular types recommended?

Several studies have shown the benefit of different probiotic supplements for PwPs as a treatment for constipation. For those PwPs on levodopa treatment this leads to an improvement in symptoms due to improved uptake of the drug from the gut from where it travels in the blood to cross the blood-brain barrier into the brain. However, there is very little research on the effect of probiotics on Parkinson’s progression. A very recent study using the probiotic Symprove in rats showed positive signals and we wait with anticipation for the results of the UK Symprove study in PwPs, which is due to finish this summer.

Research has shown again and again that people with Parkinson’s have high levels of lactobacillus bacteria in their guts. These bacteria are normally known to be anti-inflammatory, so the question remains as to why they are high in PwPs. One hypothesis is that it is the gut’s way of trying to reduce inflammation by overproducing these bacteria. Some strains of lactobacillus are able to produce enzymes that can break down levodopa medication into dopamine while in the gut. One theory is that the levodopa medication drives the proliferation of lactobacillus by providing a feeding ground for them. Until there is more definitive research on the types of probiotic strains that are safe for PwPs, it is probably advisable to be careful of taking any probiotic off the shelf. In the meantime, discuss with your neurologist whether you should be taking a probiotic product and, if so, which one you should take.

PwPs can also improve the good bacteria in their guts by eating foods that provide nourishment to help the good bacteria grow. These are known as prebiotic foods and include many of the Mediterranean foods, such as wholegrains (barley, couscous, wheat bran, rye bread and oats), leafy green veg (cabbage, asparagus, spring onions) and other vegetables such as garlic, onion, beetroot, fennel bulb, green peas, snow peas, sweetcorn and artichoke, pulses (chickpeas, red kidney beans, lentils and baked beans), and fresh and dried fruits (dried dates and figs, nectarines, bananas and watermelon).

Can you tell us how eating protein can affect levodopa absorption and what can be done about this?

It is a well-known phenomenon that when protein foods break down into amino acids in our digestive system, they travel from the small intestine via your bloodstream to cross the blood-brain barrier. Unfortunately, levodopa medication crosses at the same point in the blood-brain barrier as the amino acids. This can reduce the amount of levodopa that is absorbed, which can result in symptoms not being as well controlled. Therefore, some PwPs may benefit from taking levodopa 30-60 minutes before a protein-rich meal or 60-120 minutes afterwards.

For those who are taking levodopa medication more than five to six times a day and experiencing a lot of symptom fluctuations, this timing between food can become very difficult. For some of these PwPs, a protein re-distribution diet (PRD) can be really beneficial. A PRD means that most of your protein is eaten in the evening. This means that the levodopa has very little protein to compete with during the day when breakfast, lunch and any snacks are low in protein. However, the issue with this diet is that people sometimes end up not eating their required protein to maintain weight and muscle which will have a negative impact on Parkinson’s. It is therefore advisable to follow this diet under the guidance of a dietitian.

On the flip side, there are some people who suffer from dyskinesiasyounger-onset Parkinson’s (YOPD) and women with Parkinson’s, who may find that if they time their levodopa medication separate from protein-containing meals that their dyskinesias may get worse due to better absorption of levodopa. Hence a protein re-distribution diet would make dyskinesias worse. However, a treating neurologist may consider reducing the levodopa dosage alongside the PRD to achieve better symptom control but with less dyskinesia.

Healthy food guide concept. Vector flat modern illustration. Animal and plant protein compare Infographic with product icon and name labels.

Just as protein can impact the absorption of levodopa across the brain, high-fat and high-protein meals such as a roast dinner can slow down the emptying of the stomach. This means that your levodopa tablet remains in the stomach longer before moving to the small intestine where it is absorbed to travel to your brain. The longer the tablet is in the stomach the more the tablet can be broken down, meaning less levodopa gets to your brain. This may mean that your symptoms are not as well controlled. So, if you are going out for a three-course meal, you need to consider what your medication timing is and choose wisely on the menu: go for vegetarian dishes and avoid dishes high in dairy-based sauces.

But to be honest, everyone is different with regards to the impact protein foods and larger meals have on their medication absorption. The only way to know for sure how you respond is to track when and what you eat in relation to your levodopa medication and how your symptoms respond. By tracking your food, medication and symptoms you can get a picture of what is going on and you can share with your neurologist to see what adaptations you can make.

Are there any foods PwPs should eat or avoid eating?

As with the general population, PwPs should limit foods and drinks high in fat, sugar, and salt such as cakes, biscuits, fizzy, sweetened drinks, takeaway meals, eat less red and processed meat and drink less alcohol. Similarly, they should focus on eating a more plant-based diet by increasing wholegrain foods, fruit and vegetables, olive oil and olives, pulses, white and oily fish, nuts, seeds, and spices. PwPs should eat more berries, green leafy vegetables, olives and olive oil and prebiotic foods as I mentioned in part one of this feature.

Should PwPs eat dairy?

A set of dairy products.Milk, yogurt,sour cream,cottage cheese,butter,ice cream,roquefort,parmesan, edam, tilsiter,camembert, gouda and mozzarella.Dairy products isolated on a white background.

Research shows a low to moderate association of lower-fat dairy foods with risk of developing Parkinson’s with low to no association with fermented dairy foods such as yogurt. However, the evidence is very conflicting, making it difficult to ascertain the mechanism that is linked with a risk of developing Parkinson’s. There is only one prospective study on dairy and progression of Parkinson’s, and this associated higher rates of progression in those who ate ice cream, cheese, and yogurt, yet there was no association with milk. We need more research to understand the reasons why it is associated with risk and to understand if it has any true association with progression.

There are several potential theories behind the association, including that high urate levels have been associated with lower risk of Parkinson’s while dairy is known to lower urate levels, and there is the debate about the pesticide content of dairy but this may be impacted by different countries’ agricultural practices. Then there is the probiotic and milk fat content and its effect, and a more recent theory about the effect of galactose as the mechanism behind the association. So many questions, very few coherent answers.

We must remember that association does not mean causation and that many PwPs have heart disease and high blood pressure and dairy foods have positive associations for heart health and lowering blood pressure. The MIND diet is associated with slower progression, and it recommends limiting butter and cheese due to their saturated fat content, but that low-fat milk and yogurt are fine to eat. It really comes down to the individual PwP and their medical history and tailoring dietary requirements to their own health needs. However, the confusion over dairy continues to be one of the most common questions by PwPs and as it is a food that in moderation can confer many benefits there really needs to be more clarity through more targeted research.

Should PwPs eat gluten?

I have coeliac disease, which I think may somehow through a gut-brain connection be associated with my Parkinson’s and, anecdotally, I certainly seem to have come across a fair few people with both diseases. However, being gluten-free obviously did not reduce my risk of getting Parkinson’s! The evidence does not currently show a strong association between the two conditions. My own theory is that it may be due to gluten affecting the leakiness of the gut and the misfolding of alpha synuclein in the enteric nervous system creating a perfect storm.

A gluten-containing diet does not cause Parkinson’s and there is no need for people to follow a gluten-free diet unless they have coeliac disease or non-coeliac gluten sensitivity. Unfortunately, people who eat a gluten-free diet can be lacking in the many nutrients that are good for Parkinson’s such as wholegrains, fibre and B vitamins due to the lower fibre content of their diets. PwPs who also have coeliac disease need to work harder to ensure they get wholegrains and fibre into their diet which as we know are important for PwPs.

How does having Parkinson’s influence what you eat personally?

I always had a healthy diet, but I am probably more conscious now of following the Mediterranean/MIND dietary patterns – increasing my berry intake and eating more Vitamin C-rich foods. I also find that me and alcohol don’t mix very well together anymore so I have the very odd glass of wine.

I also discovered that my long-standing low blood pressure may have been a prodromal symptom and I have managed that through ensuring I drink a pint of cold water first thing in the morning and ensure I drink 2 litres of fluid daily. If I’m exercising or if it’s hot outside, I drink more. I also take extra salty snacks if needed. I sea-swim and I was advised that the cold water can cause blood-pressure drops, so I drink 1-2 pints of cold water to increase my blood volume before going in the sea. This, along with specific exercises such as the ‘butt clench’, helps to keep my blood pressure up.

Food guide concept. Vector flat modern illustration. Mediterranean diet infographic pyramid with label, rules and recomendation. Colorful food, meat, fruit and vegetables icon set. Water and alcohol.

I was put on a tablet to increase fluid retention and it has made a massive difference, ridding me of some terrible episodes of dizziness and nausea which were quite debilitating at times.

I am mindful that it takes longer for me to pass a bowel motion, so I ensure that my diet is high in wholegrains and fruit and vegetables and pulses to keep the bowel moving. I also take my medication half an hour before my meals where possible and if not, I take it a good hour after meals and I keep on top of my weight, ensuring I don’t lose weight and maintain my muscle mass.

Finally, I ensure I take freshly squeezed orange juice with my tablets and plenty of water to ensure my tablets go down my oesophagus. I use cold and sometimes fizzy water to stimulate my swallow and sometimes I eat a chopped apple if I have the sensation where I feel my tablet hasn’t gone down. Thanks to attending the World Parkinson Congress in Kyoto in 2019 I learnt from a Japanese speech pathologist that I should get a video fluoroscopy – a study of my swallow – done. It took me almost a year to get it after much personal medical expense to find out at the age of 48 that I had the swallow of a 65-year-old. So, I did the LSVT Loud programme with my speech and language therapist followed by Expiratory Muscle Strength Training, which improved my swallow and voice function. After a hiatus of almost two years waiting for a follow-up post-Covid, I am finally back with my SLT ready to keep on top of my voice and swallow strength. I recommend that every PwP should have a baseline swallow assessment (ideally with a video fluoroscopy) with an SLT.

Read part one of Richelle’s diet and nutrition advice