Wild Blueberry Supplementation Supports Memory in Older Adults

Written by Angeline A. De Leon, Staff Writer. Study results suggest that supplementation with a proprietary formulation of purified wild blueberry extract (WBE111), with a polyphenol profile as low as 50 mg, is associated with improved episodic memory performance and reduced systolic blood pressure in older adults. 

Considered a superfood, blueberries rank as one of the most powerful sources of antioxidants, with a flavonoid profile ranging from anthocyanins and catechins to quercetins and proanthocyanidins ¹. Flavonoids are associated with various neuroprotective effects, including the ability to promote neuronal function, stimulate neuronal regeneration, and protect against oxidative stress ². There is also evidence that supplementation with blueberry flavonoids can induce beneficial changes in vascular function ³, which are, in turn, associated with acute and chronic improvements in learning and memory ⁴. In children, acute consumption of blueberries (in powder form) has been found to enhance delayed recall accuracy and delayed word recognition ⁵, while in older adults and individuals with mild cognitive impairment, 12 weeks of blueberry supplementation (in juice form) has been linked to improved episodic memory ⁶ and increased brain activity in areas of the executive function network ⁷. Based on such findings, scientists hypothesize that polyphenols may be helpful in preventing age-related cognitive decline in older adults, although the exact relationship between cognitive performance and flavonoid dose and treatment duration are not yet clearly established ⁸. In a study ⁹ published in Nutrients, a team of researchers in the UK conducted a controlled trial examining the efficacy of a proprietary wild blueberry powder (stabilized with L-cysteine and L-glutathione to improve anthocyanin bioavailability and bioactivity) in improving memory, executive function, and mood and cardiovascular health in older adults.

A total of 122 healthy, independently living older adults (mean age = 70.8 years) with self-reported memory complaints were enrolled in a randomized, double-blinded, placebo-controlled study in which they were randomly assigned to a 6-month daily regimen of whole wild blueberry powder at 500 mg (WBP500), whole wild blueberry powder at 1000 mg (WBP1000), a purified extract at 100 mg (WBE111), or placebo (maltodextrin and food grade dye). At baseline, month 3, and month 6, participants completed a battery of cognitive tasks assessing episodic memory (Rey’s Auditory Verbal Learning Task, RAVLT; Corsi Blocks task), working memory (Corsi Blocks Task, Sternberg Memory Scanning Task), and executive function (Modified Attention Network Task, MANT; Stroop Task). Researchers also evaluated mood using the Positive and Negative Affect Schedule-NOW (PANAS-NOW) and examined systolic and diastolic blood pressure, as well as heart rate, following the cognitive test battery.

Analyses revealed that intervention with wild blueberry significantly predicted delayed word recognition on the RAVLT (F(3, 92) = 4.4, p = 0.006), with significantly better performance following WBE111 treatment vs. placebo (mean score of 0.926 vs. 0.871, p = 0.038) at 3 months. On the Corsi Blocks Task, as well, intervention significantly predicted performance (F(3, 101) = 4.05, p = 0.009), with better performance following WBE11, compared to placebo (mean score of 16.19 vs. 15.14, p = 0.069) at 3 months. Finally, examining markers of cardiovascular health, intervention significantly predicted systolic blood pressure (F(1, 102) = 2.88, p = 0.040), revealing lower blood pressure following WBE111 treatment vs. placebo (mean = 116 vs. 122 mmHg, p = 0.039), equivalent to a mean reduction of –3.09 mmHg from baseline to month 3 and –6.99 mmHg from baseline to month 6.

Based on the results of the study, researchers suggest that supplementation with a proprietary formulation of purified wild blueberry extract (WBE111), with a polyphenol profile as low as 50 mg, is associated with improved episodic memory performance and reduced systolic blood pressure in older adults. Findings are in line with the documented benefits of a polyphenol-rich diet for cognitive function in older adults ^9. The absence of positive effects for WBP500 and WBP1000 may be related to the lower dosage of anthocyanin (2.7 mg and 1.35 mg, respectively, vs. 7 mg in WBE111), but further research is needed to confirm this. Weaknesses of the study include failure to take physical measures of flavonoid metabolism during the intervention, which may have helped elucidate the lack of significant findings at 6 months (confirming whether or not increased tolerance to WBE was a factor), and the assessment of mood at the end of cognitive testing rather than the beginning, potentially confounding mood effects due to mental fatigue. It would be valuable for future studies to replicate findings in a clinical population of older adults.

Source: Whyte AR, Cheng N, Fromentin E, et al. 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; 10: 660. DOI: 10.3390/nu10060660.

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

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Posted February 18, 2019.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.

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