A Randomized, Double-Blinded, Placebo-Controlled Study to Compare the Safety and Efficacy of Low Dose Enhanced Wild Blueberry Powder and Wild Blueberry Extract (ThinkBlue™) in Maintenance of Episodic and Working Memory in Older Adults

Nutrients. 2018 May 23;10(6):660. doi: 10.3390/nu10060660.


Previous research has shown beneficial effects of polyphenol-rich diets in ameliorating cognitive decline in aging adults. Here, using a randomized, double blinded, placebo-controlled chronic intervention, we investigated the effect of two proprietary blueberry formulations on cognitive performance in older adults; a whole wild blueberry powder at 500 mg (WBP500) and 1000 mg (WBP1000) and a purified extract at 100 mg (WBE111). One hundred and twenty-two older adults (65⁻80 years) were randomly allocated to a 6-month, daily regimen of either placebo or one of the three interventions. Participants were tested at baseline, 3, and 6 months on a battery of cognitive tasks targeting episodic memory, working memory and executive function, alongside mood and cardiovascular health parameters. Linear mixed model analysis found intervention to be a significant predictor of delayed word recognition on the Reys Auditory Verbal Learning Task (RAVLT), with simple contrast analysis revealing significantly better performance following WBE111 at 3 months. Similarly, performance on the Corsi Block task was predicted by treatment, with simple contrast analysis revealing a trend for better performance at 3 months following WBE111. Treatment also significantly predicted systolic blood pressure (SBP) with simple contrast analysis revealing lower SBP following intervention with WBE111 in comparison to placebo. These results indicate 3 months intervention with WBE111 can facilitate better episodic memory performance in an elderly population and reduce cardiovascular risk factors over 6 months.

Keywords: anthocyanin; blood pressure; cognition; episodic memory; flavonoid; older adults; wild blueberry.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Affect / drug effects
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Blueberry Plants / chemistry*
  • Cognition / drug effects*
  • Cognitive Aging*
  • Double-Blind Method
  • England
  • Executive Function / drug effects
  • Female
  • Fruit / chemistry
  • Geriatric Assessment
  • Humans
  • Male
  • Memory, Episodic*
  • Memory, Short-Term / drug effects*
  • Neuropsychological Tests
  • Nootropic Agents / adverse effects
  • Nootropic Agents / isolation & purification
  • Nootropic Agents / therapeutic use*
  • Phytotherapy
  • Plant Extracts / adverse effects
  • Plant Extracts / isolation & purification
  • Plant Extracts / therapeutic use*
  • Powders
  • Time Factors
  • Treatment Outcome


  • Nootropic Agents
  • Plant Extracts
  • Powders