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Dietary flavanols linked to improved cognition in older adults

High intake of dietary flavanols improved cognition in older adults, according to new research.

After mapping cerebral blood volume in the dentate gyrus (DG) region of 35 healthy individuals, researchers at Columbia University determined that the region is “most reliably affected” by aging, and they postulated that a dietary intervention targeting the DG could improve cognition. A cognition test based on the Benton Visual Retention Test (ModBent) was developed to track cognition in a 3-month dietary intervention randomized, controlled trial of 37 healthy but sedentary adults aged 50 to 69 years.

The cohort was divided into four groups: two high-flavanol intake groups (900 mg cocoa flavanols and 138 mg (−)-epicatechin daily), one with and one without a specific regimen of aerobic exercise; and two low-flavanol intake groups (10 mg cocoa flavanols and <2 mg (−)-epicatechin daily), one with and one without a specific aerobic exercise regimen.

Participants completed a battery of neuropsychological tests and MRI sessions at baseline and after the 90-day intervention to test the hypothesis that if changes in the DG is a source of age-related cognitive decline, then an intervention could improve cognition by increasing blood flow to the region, thus enhancing DG function.

Cognitive performance on the ModBent test improved by an average of 630 milliseconds in the high-flavanol intake group, but exercise showed no significant effect.

“We note that previous studies, including our own, have documented that aerobic exercise, when effective at increasing aerobic fitness, typically improves hippocampal function,” the researchers wrote. “One possibility is that a more stringent exercise regimen is required at the older ages that we investigated.”

The increase in DG function shown on MRI screenings of the brains of participants in the high-intake flavanol groups may result from an increase in blood flow or a selective increase in capillary density, according to the researchers.

“We favor the latter interpretation because of the confined anatomical distribution of the observed effect. By either mechanism, however, our results indicate that dietary cocoa flavanol consumption enhanced DG function in the aging human hippocampal circuit,” the researchers concluded.

Disclosure: See the study for a full list of relevant financial disclosures.