Low-fat versus ketogenic diet in Parkinson's disease: A pilot randomized controlled trial

Mov Disord. 2018 Aug;33(8):1306-1314. doi: 10.1002/mds.27390. Epub 2018 Aug 11.

Abstract

Background: Preliminary evidence suggests that diet manipulation may influence motor and nonmotor symptoms in PD, but conflict exists regarding the ideal fat to carbohydrate ratio.

Objectives: We designed a pilot randomized, controlled trial to compare the plausibility, safety, and efficacy of a low-fat, high-carbohydrate diet versus a ketogenic diet in a hospital clinic of PD patients.

Methods: We developed a protocol to support PD patients in a diet study and randomly assigned patients to a low-fat or ketogenic diet. Primary outcomes were within- and between-group changes in MDS-UPDRS Parts 1 to 4 over 8 weeks.

Results: We randomized 47 patients, of which 44 commenced the diets and 38 completed the study (86% completion rate for patients commencing the diets). The ketogenic diet group maintained physiological ketosis. Both groups significantly decreased their MDS-UPDRS scores, but the ketogenic group decreased more in Part 1 (-4.58 ± 2.17 points, representing a 41% improvement in baseline Part 1 scores) compared to the low-fat group (-0.99 ± 3.63 points, representing an 11% improvement) (P < 0.001), with the largest between-group decreases observed for urinary problems, pain and other sensations, fatigue, daytime sleepiness, and cognitive impairment. There were no between-group differences in the magnitude of decrease for Parts 2 to 4. The most common adverse effects were excessive hunger in the low-fat group and intermittent exacerbation of the PD tremor and/or rigidity in the ketogenic group.

Conclusions: It is plausible and safe for PD patients to maintain a low-fat or ketogenic diet for 8 weeks. Both diet groups significantly improved in motor and nonmotor symptoms; however, the ketogenic group showed greater improvements in nonmotor symptoms. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Keywords: MDS-UPDRS; Parkinson's disease; ketogenic diet; low-fat diet.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Blood Glucose / metabolism
  • Diet, Fat-Restricted / methods*
  • Diet, Ketogenic / methods*
  • Female
  • Follow-Up Studies
  • Humans
  • Ketones / blood
  • Male
  • Middle Aged
  • Neuropsychological Tests
  • Outcome Assessment, Health Care
  • Parkinson Disease / diet therapy*
  • Pilot Projects
  • Severity of Illness Index

Substances

  • Blood Glucose
  • Ketones

Associated data

  • ANZCTR/ACTRN12617000027314