(P22-020-25) Varying Protein Patterns in the Management of Parkinson’s Disease: Results of a Pilot Randomized Controlled Crossover Study

Objectives: The optimal dietary pattern for patients with Parkinson’s disease (PPD) to manage known food-medication interaction with levodopa-carbidopa (Ldopa) remains unclear. The purpose of this study is to explore the feasibility and preliminary data on the impact of dietary protein patterns on muscle strength and PD symptoms.

Methods: In this 5-week randomized crossover pilot study, PPD who were >45 years with a diagnosis of >5 years on a stable Ldopa regimen with motor fluctuations were recruited through local clinics and support groups. With a goal of n=12, eligible PPD were randomly assigned to start on a Protein Consistent (PCD) or Protein Redistributed diet (PRD) for 2 weeks, return to their habitual diet for a 1-week washout period, and then follow the subsequent diet for 2 weeks. PPD received one-on-one counseling from a Registered Dietitian, meal plans, shopping lists, and recipes for both diets. PPD maintained logs, and they were assessed at weeks 0, 2, 3, and 5 that included the Movement Disorder Society United Parkinson’s Disease Rating Scale (MDS-UPDRS) and handgrip dynamometry. Feasibility measures included process evaluations, attrition rate, and acceptability data from individual interviews. Descriptive statistics, paired t-tests, and confidence intervals (CI) at p< .1 were used for quantitative analysis.

Results: Thirty PPD were screened, 15 were eligible (50%), and 12 consented to participate (40% of screened). One participant withdrew due to an unrelated medical event, and 11 participants (8% attrition) completed all study procedures. Mean dominant-side handgrip strength scores, pre- and post-diet, were 73.0 and 70.7 on PRD (CI –1.2, 5.8; p=.26), and 74.6 and 75.7 on PCD (CI –5.0, 2.8; p=.62). Mean MDS-UPDRS scores, pre- and post-diet were 52.9 and 47.2 on PRD (CI –1.4, 11.2; p=.19) and 51.2 and 48.8 on PCD (-3.7, 8.5; p=.49). Participants shared that they enjoyed the experience of participating in a PD-specific diet trial, but not everyone had noticeable changes in symptoms during the study.

Conclusions: This pilot study revealed highly variable data that could be due to moderate diet adherence, disease heterogeneity, or other factors. The intervention and study procedures were generally feasible and acceptable, and there are noted improvements to be made prior to the implementation of a full-scale clinical trial.

Funding Sources: NIDDK