Polyphenols tied to lower risk of cognitive decline in new studies

Photo © iStockphoto.com/Jacob Wackerhausen

Using data pulled from a 12-year study on serious diseases in the elderly, researchers have concluded that a diet rich in polyphenols may lower the risk of dementia and Alzheimer’s disease late in life.¹ Polyphenols are found in a wide variety of plant foods and drinks, and they are the focus of many intervention and population studies on cognitive decline.

In a collaborative effort between multiple French institutions and Harvard University, researchers created a cohort study based on data from the 3C Study, a long-term observational study on the elderly in France. Specifically, the researchers calculated polyphenol intake (based on a one-time baseline dietary assessment) and incidence of dementia and Alzheimer’s disease over a 12-year follow-up period.

Based on the data, subjects who consumed the most polyphenols were at a much lower risk of dementia compared to those who consumed the least polyphenols. Compared to the lowest quintile of polyphenol consumers, the highest quintile had an approximately 50% lower risk of dementia and Alzheimer’s disease over 12 years.

Despite such a profound conclusion, the researchers admitted one potential weakness to their study. “Our study is limited by the availability of a single 24-hour recall to assess polyphenol intake,” wrote the lead author. “A reported single day of intake may not fully capture individual variations in dietary habits and might lead to misclassifications; however, when sample size is sufficiently large, a single 24-hour recall can be used to assess average intakes in subgroups of a population.”

Polyphenols are abundant in our food supply. In this case, they were recorded in the following foods: nuts, citrus, berries, leafy vegetables, soy, cereals, olive oil, red wine, and tea.

Nutritional Outlook was alerted to this study by Activ’Inside (Beychac-et-Caillau, France), a polyphenol ingredient manufacturer and one of the cohort study’s sponsors. The company’s Memophenol ingredient, which is a combination of French grape and wild blueberry polyphenols, was featured in a separate cognitive-health study just published in The Journals of Gerontology.²

In that study, 215 elderly subjects aged 60- to 70-years-old consumed either 600 mg of the polyphenols or placebo daily for six months. Subjects underwent Verbal Recall Memory testing (to assess short-term memory) and Paired Associated Learning testing (to assess long-term episodic memory) at baseline and at the end of six months.

Researchers found that after six months of supplementation, Memophenol subjects saw significant improvements in Verbal Free Recall Recognition Memory scores. In addition, in a subgroup of participants with advanced cognitive decline, consumption of polyphenols was associated with improvements in episodic memory. The potential association between these outcomes and polyphenol consumption was reinforced by the detection of higher concentrations of polyphenol metabolites in urine.

“This publication is a new piece of the Memophenol puzzle,” said Benoit Lemaire, CEO, Activ’Inside, in a press release. Lemaire noted that Memophenol is supported by 10 publication and one patent.

Seppic Inc. is the exclusive distributor for Activ'Inside ingredients in North America.

References:

1. Lefèvre-Arbogast S et al. “Pattern of polyphenol intake and the long-term risk of dementia in older persons.” Neurology. Published online April 27, 2018.
2. Bensalem J et al. “Polyphenols from grape and blueberry improve episodic memory in healthy elderly with lower level of memory performance: a bicentric double-blind, randomized, placebo-controlled clinical study.” The Journals of Gerontology: Series A. Published online July 19, 2018.