Get access

Enzogenol for cognitive functioning in traumatic brain injury: a pilot placebo-controlled RCT

Authors

  • A. Theadom,

    1. National Institute for Stroke and Applied Neurosciences, School of Rehabilitation and Occupation Studies, AUT University, Auckland, New Zealand
    2. Person Centred Research Centre, School of Rehabilitation and Occupation Studies, AUT University, Auckland, New Zealand
    Search for more papers by this author
  • S. Mahon,

    1. National Institute for Stroke and Applied Neurosciences, School of Rehabilitation and Occupation Studies, AUT University, Auckland, New Zealand
    Search for more papers by this author
  • S. Barker-Collo,

    1. Department of Psychology, University of Auckland, Auckland, New Zealand
    Search for more papers by this author
  • K. McPherson,

    1. Person Centred Research Centre, School of Rehabilitation and Occupation Studies, AUT University, Auckland, New Zealand
    Search for more papers by this author
  • E. Rush,

    1. Centre for Physical Activity and Nutrition, AUT University, Auckland, New Zealand
    Search for more papers by this author
  • A. C. Vandal,

    1. Faculty of Health and Environmental Sciences, AUT University, Auckland, New Zealand
    2. Centre for Clinical Research and Effective Practice, Auckland, New Zealand
    Search for more papers by this author
  • V. L. Feigin

    Corresponding author
    • National Institute for Stroke and Applied Neurosciences, School of Rehabilitation and Occupation Studies, AUT University, Auckland, New Zealand
    Search for more papers by this author

Correspondence: V. L. Feigin, Faculty of Health and Environmental Studies, School of Rehabilitation and Occupation Studies, School of Public Health and Psychosocial Studies, National Institute for Stroke and Applied Neurosciences, AUT University, AUT North Shore Campus, AA254, 90 Akoranga Dr, Northcote 0627, Private Bag 92006, Auckland 1142, New Zealand (tel.: +64 9 921 9166; fax: +64 9 921 9620; e-mail: valery.feigin@aut.ac.nz).

Abstract

Background and purpose

Enzogenol, a flavonoid-rich extract from Pinus radiata bark with antioxidant and anti-inflammatory properties has been shown to improve working memory in healthy adults. In traumatic brain injury (TBI), oxidation and inflammation have been linked to poorer cognitive outcomes. Hence, this phase II, randomized controlled trial investigated safety, compliance and efficacy of Enzogenol for improving cognitive functioning in people following mild TBI.

Methods

Sixty adults, who sustained a mild TBI, 3–12 months prior to recruitment, and who were experiencing persistent cognitive difficulties [Cognitive Failures Questionnaire (CFQ) score > 38], were randomized to receive Enzogenol (1000 mg/day) or matching placebo for 6 weeks. Subsequently, all participants received Enzogenol for a further 6 weeks, followed by placebo for 4 weeks. Compliance, side-effects, cognitive failures, working and episodic memory, post-concussive symptoms and mood were assessed at baseline, 6, 12 and 16 weeks. Simultaneous estimation of treatment effect and breakpoint was effected, with confidence intervals (CIs) obtained through a treatment–placebo balance-preserving bootstrap procedure.

Results

Enzogenol was found to be safe and well tolerated. Trend and breakpoint analyses showed a significant reduction in cognitive failures after 6 weeks [mean CFQ score, 95% CI, Enzogenol versus placebo −6.9 (−10.8 to −4.1)]. Improvements in the frequency of self-reported cognitive failures were estimated to continue until week 11 before stabilizing. Other outcome measures showed some positive trends but no significant treatment effects.

Conclusions

Enzogenol supplementation is safe and well tolerated in people after mild TBI, and may improve cognitive functioning in this patient population. This study provides Class IIB evidence that Enzogenol is well tolerated and may reduce self-perceived cognitive failures in patients 3–12 months post-mild TBI.

Ancillary