Effects of Wild Blueberry Ingestion on Motor Performance of People With Parkinson's Disease

Effects of Wild Blueberries on Motor Performance of Parkinson's Patients: A Preliminary Clinical Trial

The purpose of this study involved investigating the effects of daily ingested wild blueberry drink (22.5 g wild blueberry powder added to pineapple juice) for 8 weeks on movement of people diagnosed with Parkinson's disease. Specifically, we questioned:

• Do the movements of people with Parkinson's disease improve after ingesting the blueberry drink once a day for 8 weeks?
• Do the movements of people with Parkinson's disease after ingesting the blueberry drink show benefits compared to people with Parkinson's ingesting a placebo drink?

Participants will:

• Drink blueberry drink or placebo once a day for 8 weeks
• Visit the neurologist before and after the intervention period
• Complete assessments before and after the intervention period
• Visit the lab weekly for checkups and to obtain more powder and juice
• Keep a diary of time of ingestion and adverse effects. We hypothesized that supplementation with wild blueberry powder will result in favorable improvements in movements in people with Parkinson's disease that exceed placebo supplementation.

Study Overview

• Status: Completed
• Conditions: Parkinson's Disease
• Intervention / Treatment: Dietary supplement: Wild blueberry powder; Other: Placebo

Detailed Description

The purpose of this study involved investigating the effects of daily ingested wild blueberry drink (22.5 g wild blueberry powder added to pineapple juice) for 8 weeks on movement of people diagnosed with Parkinson's disease. Specifically, we questioned:

• Do the movements of people with Parkinson's disease improve after ingesting the blueberry drink once a day for 8 weeks?
• Do the movements of people with Parkinson's disease after ingesting the blueberry drink show benefits compared to people with Parkinson's ingesting a placebo drink? We hypothesized that supplementation with wild blueberry powder will result in favorable improvements in movements in people with Parkinson's disease that exceed placebo supplementation.

Drinks After meeting entry criteria, people were randomized to receive 22.5 g of wild blueberry powder (equivalent to 1 cup of wild blueberries) or control/placebo added to 170 g of pineapple juice with about four ice cubes and consumed as one drink per day. Participants received at least seven individual powder packets sealed in a baggy along with at least eight 6 oz cans of 100% Dole pineapple juice for each week of the intervention (we included extra in anticipation of rescheduling or mishandling). Most people used their own blender for mixing the drink; however, a few used the shaker bottles with stainless steel wire whisk. Participants returned empty packets, as confirmation of ingestion, during lab visits.

Freeze-dried wild blueberry powder included quick frozen and dehydrated wild blueberries to reduce the moisture content to approximately 2-4%. Placebo matched nutritional properties minus the polyphenols. The Wild Blueberry Association of North America provided BB and placebo powder.

Three pre-screening visits allowed us to ensure participants met study criteria and to start pre-intervention assessments. During visit 1/week -3, we obtained consent, surveyed inclusion/exclusion criteria, measured height and weight, assessed cognition (Mini Mental State Exam), obtained a list of concomitant medication, and completed the taste test to ensure participants agreed to consume either the Placebo and BB drinks for 8 weeks. During visit 2/week -2 and after a 12 hour OFF PD medication (24 hour for dosing once daily) and food withdrawal, participants saw a movement disorder neurologist to complete a physical and neural examination including non-dilated fundoscopic evaluation, obtain vitals, obtain medical history and concomitant medication, assess Hoehn and Yahr stage of PD, and assess motor symptom severity via the Unified Parkinson's Disease Rating Scale (UPDRS-III). Predetermined laboratory assessments at this visit included pregnancy test (if applicable), urinalysis, fasting glucose, and insulin, CHEM 15, and a CBC panel. Visit 3/week -1 involved collection of weight, blood pressure, heart rate, temperature, pulse oxygen, updated medication list, a weekly Food Frequency Questionnaire (FFQ) to determine how many berries, grapes, cherries, juices, or wine people consumed in the previous week, UPDRS-III, and functional assessments to expose participants to objective and clinical measures of standing balance, gait, and physical function used for pre and post intervention while on their normal medication schedule. We explained and provided instructions on how to complete nutritional assessments involving a 3-day food record which included details about all food consumption for 3 non-consecutive days (time, location, what, and how much consumed) and a Diet History Questionnaire II requesting what, how often, and how much they ate of different foods over the last year. Researchers instructed participants how to wear a waist-mounted activity monitor for seven days and provided verbal and written instructions to record the start time and type of each activity in an activity diary. We called participants three times during the next seven days to help ensure adherence. We also encouraged participants to call investigators with questions/concerns.

Week 0 involved pre-testing not completed at the physician visit with similar procedures and content to week -1. Assessments included weight, blood pressure, heart rate, temperature, pulse oxygen, updated medication list, a weekly FFQ, UPDRS-III, and functional assessments. We reviewed the nutritional assessments and activity diary for accuracy, updating incomplete items, and retrieved the activity monitor. Each newly randomized participant received powder packets (BB or Placebo), pineapple juice, instructions on how to mix their drink, and adverse events diary, in which people reported the time of drink consumption and whether any adverse events occurred that day. Again, we called participants three times each week through study completion to help ensure they consumed the drink and completed adverse events log and encouraged them to call investigators with questions/concerns.

During weeks 1-6, we recorded weight, blood pressure, heart rate, temperature, pulse oxygen, a weekly FFQ, and reviewed the presence of adverse events, if any. Participants brought back empty packets as evidence of ingestion. Collections occurred weekly for most participants, allowing them to pick up more powder and juice for the next week. For those living farther away or with conflicts, we collected as much data as possible over the phone and ensured we sent home enough powder and juice until their next visit.

One week before the final visit in addition recording weight, blood pressure, heart rate, temperature, pulse oxygen, a weekly FFQ, and reviewing the presence of adverse events, we reviewed and provided instructions on how to complete the 3-day food record and activity diary and how to wear the activity monitor. This occurred around week 7-8.

For the last visits (week 8 ± 1 week), we repeated the visit to the neurologist after the food and PD medication (OFF) withdrawal (visit 2) and without the possible pregnancy test. During a separate visit because of the ON medication requirement, we collected weight, blood pressure, heart rate, temperature, pulse oxygen, updated medication list, a weekly FFQ, UPDRS-III, and functional assessments for post-testing. We reviewed the 3-day food record and activity diary for accuracy and updated incomplete items. We also received the activity monitor and downloaded the data.

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • Louisiana
    • Baton Rouge, Louisiana, United States, 70808
      • Pennington Biomedical Research Center
    • Baton Rouge, Louisiana, United States, 70810
      • The Baton Rouge Neuromedical Center, The Spine Hospital of Louisiana
    • Baton Rouge, Louisiana, United States, 80803
      • Sensorimotor/Motor Control Lab, Louisiana State University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Men and women diagnosed with Stage 1-3 Parkinson's disease (Hoehn & Yahr) as confirmed at the first screening visit by the study neurologist and meeting all criteria listed below will be included in the study:

• 50-89 years of age.
• BMI 18.5-40.
• Stable on medications for at least 2 months.
• Walks w/o assistive device.
• Maintain consistent activity levels for 30 days prior to and during study.
• Willing to consume 22.5 mg of mixed powder added to pineapple juice a day for 8 weeks.

Exclusion Criteria:

• Subjects with prior history of Type 1 or uncontrolled Type 2 diabetes (A1C > 7%).
• Subjects who are demented.
• Subjects who have severe difficulty swallowing.
• Subjects with diagnosis or signs of neuropathy.
• Subjects with evidence of rheumatoid arthritis.
• Subjects with diagnosed osteoarthritic conditions of the spine or lower extremities (including hips) sufficient to affect gait.
• Subjects with pre-existing medical condition that significantly affects gait.
• Subjects with pre-existing gait defect (unless caused by PD).
• Women who are pregnant or who are lactating.
• Women of childbearing potential who are not using an effective method of birth control (i.e., barrier method, intrauterine and cervical devices, oral contraceptives, hormonal injections (Depro Provera®), condoms with spermicidal gel or foam, contraceptive patch (Ortho Evra), diaphragm, or abstinence), are not surgically sterilized (including tubal ligation and hysterectomy), or not at least 2 years postmenopausal. All women of childbearing potential will have a pregnancy test performed at the screening. If a subject becomes pregnant during the study, they will be dropped.
• Subjects with a history or evidence of significant gastrointestinal dysfunction, e.g. irritable bowel syndrome; inflammatory bowel disease; ulcerative colitis or Crohn's disease; regional enteritis; diverticulosis or diverticulitis; significant gastroparesis; GI stricture, partial or complete gastrectomy or small bowel resection; chronic diarrhea; peptic ulceration, colonic ulceration, or GI bleeding.
• Subjects who have chronic use of laxatives or cathartics. The use of stool softeners is acceptable. Use of bulking agents, if required, should remain constant.
• Subjects who are taking concomitant therapy with medications known to be nephrotoxic, such as aminoglycosides, methicillin, and cyclosporin.
• Subjects who have evidence of clinically significant renal dysfunction or disease, e.g. serum creatinine >1.5 mg/dL in males and >1.4 mg/dL in females and/or BUN >50 mg/dL, proteinuria of >1 gram/day or 4+ proteinuria on dipstick urinalysis.
• Subjects with clinically significant cardiovascular dysfunction and/or history (within the preceding 6 months) of significant cardiovascular dysfunction, e.g., congestive heart failure or serious arrhythmia or myocardial infarction; transient ischemic attacks or cerebrovascular accident during the preceding six months; diagnosis of symptomatic autonomic neuropathy with a history of orthostatic hypertension, syncope, or hypertension with a systolic blood pressure of ≥ 180 mm Hg or diastolic blood pressure ≥110 mm Hg at the time of screening visit; history of hypotension, dizziness/fainting with systolic blood pressure of ≤ 90 mm Hg or diastolic blood pressure ≤ 60 mm Hg at the time of screening visit.
• Subjects who have evidence within the preceding 6 months of hepatic disease or dysfunction, e.g. AST, ALT, alkaline phosphatase or total bilirubin twice the upper limit of normal; hepatitis; jaundice; cirrhosis.
• Subjects with clinically significant pulmonary, neurologic, hematologic, immunologic, neoplastic or metabolic disease.
• Subjects with evidence or recurrence of malignancy within the past five years, other than excised basal cell carcinoma.
• Subjects for whom surgery is anticipated during the study period or has had surgery in the last 6-months.
• Subjects with a history of substance abuse or alcoholism within the past 5 years, or significant psychiatric disorder that would interfere with the subject's ability to complete the study.
• Subjects who have donated blood during the month prior to study entry or planned during the study.
• Subjects who have participated in other studies using an investigational drug during the preceding 3 months.
• Subjects who are allergic to blueberries or pineapple juice.
• Subjects who are allergic to red dye or blue dye food coloring.
• Subjects who consume and drink daily servings of berries (i.e., blueberries, strawberries, bilberries, cranberries, elderberries, and raspberries), grapes, fruit juices that contain berries and grapes, and wine more than 3 times per week in the preceding 2 months.
• Subjects who have had a fluctuation in body weight >10% in the preceding 2 months.
• Subjects who are taking prescription or over the counter medication or supplements for desired weight loss.
• Subjects who have peripheral vascular disease in the arms and/or legs.
• Subjects who have a history of blood clots.
• Subjects who have active deep brain stimulators.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: BB; Experimental (BB): The experimental powder consists freeze-dried wild blueberry powder included quick frozen and dehydrated wild blueberries to reduce the moisture content to approximately 2-4%.	Dietary supplement: Wild blueberry powder; Experimental (BB): The experimental powder consists freeze-dried wild blueberry powder included quick frozen and dehydrated wild blueberries to reduce the moisture content to approximately 2-4%. Added to 6oz of pineapple juice.
Placebo Comparator: Placebo; Placebo Comparator (Placebo): Placebo drink consists of matched nutritional properties minus the polyphenols for BB powder.	Other: Placebo; Placebo Comparator (Placebo): Placebo drink consists of matched nutritional properties minus the polyphenols for BB powder. Added to 6oz of pineapple juice.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gait velocity	The average time per meter it takes participants to complete their steps across a 20-foot computerized walkway. Assessment occurred under three conditions: 1) normal walking, 2) fast walking, and 3) dual-task walking (we asked participants to spell a five-letter word backwards as they crossed the walkway).	Assessed during practice, one week prior to pre-test, and at pre-test and about 8 weeks (+/- 1 week) later at post-test.
COP95	The area containing the 95% confidence ellipse encompassing the center of pressure-CoP during 30 s of standing still with either eyes opened or closed.	Assessed during practice, one week prior to pre-test, and at pre-test and about 8 weeks (+/- 1 week) later at post-test.
Step count	The average number of steps each day were averaged over the 7 days for a total step count.	Assessed the week prior to pre-testing and about 8 weeks (+/- 1 week) later at post-test.
The Timed-Up-and-Go (TUG) test	We evaluated the time to stand from a chair, walk 3 m, turn 180º, walk back, and sit down.	Assessed during practice, one week prior to pre-test, and at pre-test and about 8 weeks (+/- 1 week) later at post-test.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Unified Parkinson's Disease Rating Scale-motor section (UPDRS-III)-OFF	This assessment involves an in-depth motor examination used in clinical and research settings for PD motor symptom severity ratings and assesses: 0=no, 1=slight, 2=mild, 3=moderate, 4=severe impairment. Scores categorized as ≤ 11.2 denote mild impairment, ≥ 54.4 denote severe impairment, and > 5 point changes denote clinical significance. Movement disorder neurologists performed the UPDRS-III after a 12 hour withdrawal (or 24 hour withdrawal for once daily) from anti-Parkinson medication (OFF medication).	Assessed at pre-screening and about 9 weeks later at post-test.
Gait variability	The coefficients of variation-CV was calculated across the average length of each step (SL), width of each step (SW), and duration of each step (ST). Assessment occurred under three conditions: 1) normal walking, 2) fast walking, and 3) dual-task walking (we asked participants to spell a five-letter word backwards as they crossed the walkway).	Assessed during practice, one week prior to pre-test, and at pre-test and about 8 weeks (+/- 1 week) later at post-test.
Postural sway	Average velocity of the center of pressure-CoP (CoPVEL), CoP displacement in the mediolateral (ML) and anteroposterior (AP) directions and their variability (SD), sample entropy of CoP displacements (SENML, SENAP) to provide insight into the automaticity of sway: https://www.mathworks.com/matlabcentral/fileexchange/35784-sample-entropy with parameters r = 0.2, and m = 2 , also normalized to participant's height. Calculated from 30 s data of standing still with eyes opened and closed, seperately.	Assessed during practice, one week prior to pre-test, and at pre-test and about 8 weeks (+/- 1 week) later at post-test.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Unified Parkinson's Disease Rating Scale-motor section (UPDRS-III) ON medication	This assessment involves an in-depth motor examination used in clinical and research settings for PD motor symptom severity ratings and assesses: 0=no, 1=slight, 2=mild, 3=moderate, 4=severe impairment. Scores categorized as ≤ 11.2 denote mild impairment, ≥ 54.4 denote severe impairment, and > 5 point changes denote clinical significance. Experienced investigators performed the UPDRS-III while medicated (ON medication).	Assessed during practice, one week prior to pre-test, and at pre-test and about 8 weeks (+/- 1 week) later at post-test.
Spatial-temporal gait measures	The average length of each step (SL), width of each step (SW), duration of each step (ST), and percentage of the gait cycle in single limb support (%SS) were calculated. Assessment occurred under three conditions: 1) normal walking, 2) fast walking, and 3) dual-task walking (we asked participants to spell a five-letter word backwards as they crossed the walkway).	Assessed during practice, one week prior to pre-test, and at pre-test and about 8 weeks (+/- 1 week) later at post-test.
Physical activity level	We monitored wear time and estimation of percent of wear time spent in low (%low), moderate (%mod), and high (%high) physical activity for 7 days.	Assessed the week prior to pre-testing and about 8 weeks (+/- 1 week) later at post-test.

Collaborators and Investigators

• Sponsor: Louisiana State University, Baton Rouge
• Collaborators: Pennington Biomedical Research Center; Baton Rouge Neuromedical Center, The Spine Hospital of Louisiana
• Investigators: Principal Investigator: Jan M Hondzinski, PhD, Louisiana State University Health Sciences Center in New Orleans

Study record dates

Study Major Dates

• Study Start (Actual): August 31, 2018
• Primary Completion (Actual): April 18, 2025
• Study Completion (Actual): April 18, 2025

Study Registration Dates

• First Submitted: July 17, 2026
• First Submitted That Met QC Criteria: July 17, 2026
• First Posted (Actual): July 22, 2026

Study Record Updates

• Last Update Posted (Actual): July 22, 2026
• Last Update Submitted That Met QC Criteria: July 17, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Postural Balance; Gait Analysis; Blueberry; Fruit and Vegetable Juices; Kinesiology, Applied; Fitness Trackers
• Additional Relevant MeSH Terms: Synucleinopathies; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neurodegenerative Diseases; Movement Disorders; Parkinsonian Disorders; Basal Ganglia Diseases; Parkinson Disease
• Other Study ID Numbers: AWD-44934-1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No