Plant-based natural products for symptomatic relief of Parkinson's disease: prevalence, interest, awareness and determinants

Natural health products (NHP) have emerged as a potential symptomatic therapeutic approach for persons with Parkinsons disease (PwP). The objective of this study was to quantify the prevalence of ever use of NHP, interest in plant-based NHP, awareness of potential herb-drug interactions, and how often NHP use was discussed by PwP with their healthcare professionals. We addressed these objectives by embedding a cross-sectional 4-item survey within a large population-based cohort of PwP (PRIME-NL study). Sixty-five percent (n=367) of the 566 participants who were contacted completed the survey. Of those participants, 132 (36%) reported having used NHP to alleviate Parkinsons disease (PD)-related symptoms, with coffee, cannabis and turmeric being the most popular. Overall, 12% (n=44) of PwP had used at least one NHP other than coffee or cannabis. Furthermore, 71% (n=259) participants expressed an interest in exploring the use of NHP, but only 39% (n=51) of NHP users were aware that these products could interact with PD medication. Finally, only 39% (n=51) of NHP users had discussed the use of NHP with their neurologist or PD nurse specialist. In a sensitivity analysis, we conservatively assumed that all non-responders to the survey had never used NHP and had no interest in exploring NHP. This rendered an estimated prevalence of NHP use of 23% and an estimated interest in exploring NHP of 46%. In conclusion, over one in three PwP has used NHP to alleviate symptoms of PD and the majority of PwP is interested in exploring the use of plant-based NHP. Most users had not discussed the intake of NHP with their PD healthcare professional and were unaware that these products could interact with PD medication. This study supports the need for evidence-based research on the properties of plant-derived therapeutics.