Flavanol consumption improves hippocampal memory function associated with cognitive aging

In a recent study published in the PNAS Journal, researchers investigated the impact of dietary flavanols on the component of cognitive aging associated with hippocampus-dependent memory and the link between habitual diet quality and the benefits of flavanols for memory.

Study: Dietary flavanols restore hippocampus-dependent memory in older adults with lower diet quality and habitual flavanol intake. Image Credit: guentermanaus/Shutterstock.com

Background

Age-related decline in cognitive abilities, unrelated to various late-stage cognitive diseases, is known as cognitive aging. Studies in humans and other mammalian species have identified the hippocampus region as having one of the critical memory components associated with cognitive aging.

Since cognitive aging can significantly impact our lives and reduce quality of life as we age, identifying modifiable etiologic factors related to diet and lifestyle can significantly reduce the impact of cognitive aging. cognitive aging on public health.

Research indicates that diet quality, habitual eating habits, and specific diet components may have etiological links to cognitive aging.

Flavanols are bioactive compounds commonly found in apples, tea, berries, cocoa, grapes, and various other vegetables and fruits, and studies have shown that consuming flavanols can improve hippocampal-dependent memory and slow down cognitive aging by increasing angiogenesis.

About the study

In the present study, the researchers conducted an ancillary study to an ongoing double-blind, randomized, placebo-controlled study called the Cocoa Supplement and Multivitamin Outcomes Study (COSMOS) which examined the effect of multivitamin and extract supplementation. cocoa on total invasive cancer and cardiovascular disease. occurrence of the disease.

The intervention consisted of cocoa extract, multivitamin capsules and placebos, and included men and women over the age of 60 and 65, respectively.

The COSMOS-Web ancillary study examined the impact of flavanol supplementation on hippocampal-dependent memory. The predefined primary outcome of COSMOS-Web was the performance of the Modified Rey Auditory Verbal Learning Test (ModRey), followed by one year of intervention.

Secondary analyzes tested the modification of effects based on participants’ reported baseline dietary quality. The specificity of flavanol’s effect on hippocampal-dependent memory was tested by comparing it to performance associated with the prefrontal cortex, measured using the Flanker test.

COSMOS-Web’s online platform included a self-administered cognitive battery, which was installed through a web-based platform and run locally to circumvent Internet-based delays in recording responses. Participant performance data was automatically uploaded to the web platform after battery completion.

Cognitive outcomes were measured using ModRey’s test and Flanker’s test. The ModRey test assesses list learning and episodic memory recall, with 20 words presented to participants with three seconds per word to retain it in memory.

Participants are then asked to recall the words immediately and 20 minutes after the list is presented. In contrast, the Flanker test measures executive control. It includes trials where participants must respond to the color and direction congruence of a central arrow surrounded by other arrows on the screen.

The difference in reaction time between congruent and incongruent trials determines the size of the directional derivative effect.

The impact of flavanol consumption was assessed by analyzing changes in cognitive measures over time and associations with the Alternative Healthy Eating Index (aHEI) and 5-(3′,4′ -dihydroxyphenyl)-γ-valerolactone (gVLM) in urine.

Results

The results indicated that chronic flavanol intake and baseline diet quality were selectively and positively correlated with hippocampal-dependent memory. Memory improvements throughout the study were associated with increases in flavanol biomarkers.

Additionally, although the intervention-related memory improvement was not statistically significant at the end of the one-year trial based on the predefined endpoint tests, improvements in memory associated with flavanol consumption were observed in the lower tertiles of habitual flavanol consumption. and the quality of the usual diet.

Memory improvements were observable after one year of intervention and were maintained over the next three years of follow-up. Moreover, diet quality was more strongly associated with the hippocampal component of cognitive aging than with the prefrontal cortex component.

Additionally, increased urinary concentrations of gVLM, a flavanol biomarker, have been associated with improved hippocampal-dependent memory. In contrast, lower concentrations of gVLM in urine were linked to reduced baseline memory.

conclusion

Overall, the results indicated that flavanols were part of a healthy diet, and that habitual flavonol intake and baseline diet quality were positively associated with improvements in cognitive components of memory of aging. related to the hippocampus.

The results highlighted the importance of dietary recommendations incorporating flavanol consumption to improve brain health and function.