VU Researcher on Parkinson’s: Diet Matters Too, Not Just Medication

Parkinson’s disease is most commonly associated with tremor, slowed movement and stiffness. However, the condition has many more facets – patients may also experience anxiety, depressive mood, pain, sleep disturbances, and urinary issues. A scientific study has found that everyday dietary habits may play a role in these symptoms.

According to Dr Jevgenija Guk, a neurologist and researcher at Vilnius University, Faculty of Medicine who has studied the dietary habits of people with Parkinson’s disease, diet may be associated with some of the symptoms of the disease. 

What is Parkinson’s disease, how does it manifest itself, and what are its symptoms? 

Parkinson’s disease is a progressive neurodegenerative condition most commonly associated with movement difficulties, including limb tremor, slowed movement, muscle stiffness and impaired balance. However, in addition to motor symptoms, people with Parkinson’s disease often experience so-called non-motor symptoms. These may include constipation, sleep disturbances, anxiety, depressive symptoms, pain, a reduced sense of smell, urinary problems and other symptoms. These symptoms in particular can have a significant impact on a person’s daily activities and quality of life. 

You studied the dietary habits of people with Parkinson’s disease. Can what we eat affect the symptoms of the condition? 

Our study suggests that diet may be associated with some symptoms of Parkinson’s disease, particularly non-motor symptoms. Higher adherence to a Mediterranean diet was associated with a lower likelihood of anxiety, pain, constipation and urinary problems. However, because our study cannot establish which came first, we cannot say that diet itself reduced these symptoms. We also cannot rule out the possibility that the relationship works in the opposite direction – that the symptoms of Parkinson’s disease may have influenced patients’ dietary habits. Therefore, this association should be considered potentially bidirectional. 

What nutrients are people with Parkinson’s disease most commonly lacking? Are there foods that are worth including in almost everyone’s daily diet? 

Our study found that participants with Parkinson’s disease consumed insufficient amounts of dietary fibre, vitamin A and vitamin D compared with the recommended daily intake. We also found that, for fewer than half of all participants, the intake of protein, fat, polyunsaturated and monounsaturated fatty acids from food met the established dietary guidelines, while the proportion of energy derived from sugars exceeded the recommended amount. 

Rather than focusing on a single ‘superfood’, I would therefore recommend thinking about the overall dietary pattern: eating more vegetables, fruits, whole grains, legumes, fish, nuts and other plant-based foods. This broadly reflects the principles of a Mediterranean diet and a healthy, sustainable diet, that can also be easily adapted to Lithuanian cuisine. 

Can people expect Parkinson’s disease symptoms to improve in practice if they change their diet? 

Diet is certainly worth considering as one component of Parkinson’s disease management, but it should not be classified as a treatment. Our study identified associations between a Mediterranean diet and some non-motor symptoms of the disease. However, larger and longer-term studies are needed to determine whether dietary changes actually reduce symptoms, as well as studies examining the effects of specific dietary interventions. 

Your study found an association between adherence to a Mediterranean-style diet and the likelihood of experiencing Parkinson’s symptoms. What could this mean in practical terms for someone living with Parkinson’s disease? 

Our study revealed that individuals  with higher adherence to a Mediterranean diet had a lower likelihood of developing Parkinson’s disease, but this association emerged only after taking into account other factors that could potentially influence the results – age, sex, smoking, body mass index, physical activity, education and income. This means that a healthier dietary pattern may be one of the factors associated with the risk of Parkinson’s disease. However, our study does not allow us to conclude that diet protects against the disease or can prevent it. 

For someone living with Parkinson’s disease, a health-promoting diet may be a meaningful part of overall health and disease management. However, it should not be regarded as a substitute for medication. 

Are there any foods or dietary habits that may be unfavorable for people with Parkinson’s disease? What should patients consume less of? 

I do not believe that people with Parkinson’s disease should be told to completely eliminate any specific food group. In our study, we found that the proportion of energy derived from sugars in the diets of people with Parkinson’s disease exceeded the recommended amount, while their intake of dietary fibre, vitamin A and vitamin D was below the recommended daily intake. We also found that people with Parkinson’s disease consumed more ultra-processed foods than participants in the control group. 

It is therefore important to limit the consumption of sweets and ultra-processed foods, rather than dividing diet into ‘good’ and ‘bad’ foods. The most important thing is to maintain a varied, nutritious and balanced diet tailored to each individual’s needs. 

What would be the most important message from your research for the general public? 

The most important message from our research would be that the management of Parkinson’s disease should not be limited to medication alone. Diet is a key modifiable lifestyle factor, and our study suggests that a healthier dietary pattern, particularly a Mediterranean diet, may be associated with a lower likelihood of Parkinson’s disease and a lower risk of experiencing some non-motor symptoms. 

A nutritionally adequate, balanced diet is beneficial not only for people with Parkinson’s disease – it is also important for overall health and the prevention of other chronic conditions. It is a simple measure that we can incorporate into our daily lives, and putting it into practice does not necessarily have to be expensive. 

However, diet is not a panacea or a substitute for medical treatment. The most important thing is to assess each patient’s diet, disease symptoms, medication and nutritional needs on an individual basis.