The symptoms of Parkinson’s are not just limited to movement, they are characterised by both motor (movement) and non-motor symptoms and are different from person to person. Non-motor symptoms like loss of smell, sleep disorders, constipation and depression can precede motor symptoms by many years. A new study, published in August 2020, suggests adhering long-term to healthy diet patterns such as the alternate Mediterranean diet may be linked to having fewer of these preceding or prodromal features suggestive of Parkinson’s.
The alternate Mediterranean diet and the Alternative Healthy Eating Index
The current study analysed records from the Nurses’ Health Study and the Health Professionals Follow-up Study, which collected dietary information from participants every 4 years starting in 1986 when participants were middle-aged. Within these 2 groups, researchers calculated scores for adherence to multiple healthy diet patterns, including the alternate Mediterranean diet and the Alternative Healthy Eating Index.
The alternate Mediterranean diet score reflects an adaptation of the principles of the traditional Mediterranean diet to non-Mediterranean countries. Both the alternate Mediterranean diet and the Alternative Healthy Eating Index encourage intake of fibre rich plant foods including vegetables, fruits, whole grains, nuts and legumes. Both the alternate Mediterranean diet and the Alternative Healthy Eating Index promote intakes of healthy fats, low intakes of red and processed meats and moderate alcohol consumption.
A total of 47,679 participants were analysed in this study. Of those, 17,400 were included in a subset of participants who responded to a 2012 questionnaire on REM sleep behaviour disorder and constipation and had 5 additional prodromal features evaluated in 2014-2015 (loss of smell, impaired colour vision, excessive daytime sleepiness, body pain and depression).
Results showed participants with the highest adherence to both the alternate Mediterranean diet and Alternative Healthy Eating Index were less likely to have 3 or more non-motor symptoms that precede Parkinson’s than participants with the lowest adherence to these healthy dietary patterns. These results were found after researchers adjusted for other factors that could affect the risk of developing these preceding symptoms, such as physical activity, smoking and body mass index.
Looking at individual food groups, researchers suggested eating more vegetables, nuts, legumes and consuming moderate amounts of alcohol were all associated with a lower risk of having 3 or more of the preceding symptoms. Moderate alcohol consumption was considered no more than 1 standard drink per day for women and no more than 2 standard drinks per day for men.
Similar results have been found with respect to the Mediterranean dietary pattern in a study published in 2019 of older adults. In this study adherence to a Mediterranean diet was associated with a lower probability of developing prodromal Parkinson’s. Participants in this study with the highest adherence to the Mediterranean diet had around a 21% lower probability of developing prodromal Parkinson’s. In this study, results were driven mostly by non-motor markers of prodromal Parkinson’s including depression, constipation, urinary dysfunction and daytime somnolence. This finding may suggest that following a Mediterranean diet could delay the onset of Parkinson’s.
Results of the current study suggest long-term adherence to the Mediterranean style diet and the Alternative Healthy Eating Index may reduce the occurrence of several non-motor symptoms that precede Parkinson’s. Although the current study does not establish a causal role between following a certain healthy dietary pattern and risk of prodromal Parkinson’s features, it does provide further reasons to consume a plant based diet rich in vegetables, fruits, whole grains, nuts and legumes. More research is needed to determine if eating a certain way can delay or even prevent the development of Parkinson’s among people who have preceding or prodromal symptoms.
Molsberry S., Bjornevik K., Hughes KC., Healy B., Schwarzschild M., Ascherio A., Diet pattern and prodromal features of Parkinson’s disease, Neurology Aug 2020.
Michael E., Healthy diet linked to lower risk for symptoms preceding Parkinson’s disease, Healio, August 2020.
American Academy of Neurology, Can a healthy diet reduce risk of Parkinson’s? Eating Veggies, Nuts Linked to Fewer Symptoms that May Precede the Disease, August 2020.
Maraki MI., Yannakoulia M., Stamelou M., Stefanis L., Xiromerisiou G., Kosmidis MH., et al. Mediterranean diet adherence is related to reduced probability of prodromal Parkinson’s disease. Mov Disord. 2019, 34(1):48-57.