Reuters Health News | August 07, 2018
Polyphenol-rich extract from grape and blueberry (PEGB) appears to improve episodic memory decline in healthy elderly people with memory problems, researchers report.
“Our study demonstrates that PEGB improves age-related episodic memory decline in individuals with the highest cognitive impairments,” the authors write in their paper in The Journals of Gerontology, online July 19. “Polyphenols are promising nutritional bioactives exhibiting beneficial effect on age-related cognitive decline.”
“Taking into account their beneficial effect on health, our study confirms the need to define a recommended dietary allowance (RDA) for flavonoids and revise recommendations for foods rich in these bioactives,” they add.
Senior author Dr. Veronique Pallet of the University of Bordeaux and colleagues examined the effect of PEGB on the memory of healthy individuals between 60 and 70 years of age at one site in France and one in Canada.
Their randomized double-blind trial involved 101 volunteers who took one oral capsule containing 300 mg of PEGB at least 1 hour before breakfast and a second capsule at least 1 hour after dinner, every day for 24 weeks. The 600 mg/day of PEGB contained 258 mg of flavonoids. The 105 participants in the placebo group received capsules that contained 300 mg of pure maltodextrin with no polyphenol.
Participants were stratified into quartiles based on Paired Associate Learning (PAL) score at baseline, and a subgroup with advanced cognitive decline responded positively to the PEGB. In that group, PEGB was also linked with better VRM delayed recognition.
While among all participants, no significant effect of PEGB was found on the PAL test of visuospatial learning and episodic memory, the PEGB group improved in verbal episodic and recognition memory (VRM) free recall.
Dr. Beatrice Golomb, a professor in residence in the Department of Medicine at the University of California San Diego, in La Jolla, told Reuters Health by email, “It is important to state what is in the placebo and this is not often done. The authors are to be commended for doing so.”
“It would be useful to have the authors comment on their evidence that this wasn’t an adverse effect of maltodextrin placebo,” she added.
“Polyphenol-rich substances, like chocolate, have been specifically reported to improve blood flow to the brain, which may help in those whose memory decline is due in part to impaired blood (and corresponding oxygen, glucose, antioxidant) delivery,” she said. “And polyphenols may help in other cases where oxidative stress is a contributor to problems, such as damage to mitochondria, apoptosis, inflammation, and other mechanisms of injury.”
“Polyphenols are not going to bring back already dead cells in areas that govern memory,” Dr. Golomb said. “Much of what they can potentially do is protect from further cell loss.”
Dr. Golomb, who was not involved in the study, added, “Elderly tolerate drugs less well, and polypharmacy is a serious problem in elderly, so food-based or food-derived solutions, which tend to have lower risk of problems and drug interactions (though this is not guaranteed), are preferred when possible.”
She suggested that physicians recommend polyphenol or polyphenol-rich supplements for their elderly patients with memory problems.
“Polyphenol-rich foods have other potential benefits to health, beyond possible effects on memory,” Dr. Golomb said. “A diet high in polyphenol-rich foods—and in fruits, vegetables, nuts, and legumes more generally—is sensible, irrespective of the findings of this study.”
Story Source – site may require registration