Cocoa Compounds Reverse Age-Related Memory Decline, Study Shows

Rebecca Lewis October 27, 2014

Dietary cocoa flavanols—naturally occurring bioactive compounds found in cocoa—reversed age-related memory decline in healthy older adults, according to a new study.

Ageing is often associated with memory decline. As people age, they often encounter problems like forgetting the names of their acquaintances or where they put certain things like their car keys, purse, etc. But what causes these changes? The new study, published in the journalNature Neuroscience, provides the first direct evidence that one component of age-related memory decline in humans is caused by changes in a specific region of the brain and that this form of memory decline can be improved by a dietary intervention.

In the study, 37 healthy volunteers, ages 50 to 69, were randomized to receive either a high-flavanol diet (900 mg of flavanols a day) or a low-flavanol diet (10 mg of flavanols a day) for three months. Brain imaging and memory tests were administered to each participant before and after the study. The brain imaging measured blood volume in the dentate gyrus, a measure of metabolism, and the memory test involved a 20-minute pattern-recognition exercise designed to evaluate a type of memory controlled by the dentate gyrus.

As people age, they typically show some decline in cognitive abilities, including learning and remembering such things as the names of new acquaintances or where one parked the car or placed one’s keys. This normal age-related memory decline starts in early adulthood but usually does not have any noticeable impact on quality of life until people reach their fifties or sixties. Age-related memory decline is different from the often-devastating memory impairment that occurs with Alzheimer’s, in which a disease process damages and destroys neurons in various parts of the brain, including the memory circuits.

Previous work, including by the laboratory of senior author Scott A. Small, MD, had shown that changes in a specific part of the brain—the dentate gyrus—are associated with age-related memory decline. Until now, however, the evidence in humans showed only a correlational link, not a causal one. To see if the dentate gyrus is the source of age-related memory decline in humans, Dr Small and his colleagues tested whether compounds called cocoa flavanols can improve the function of this brain region and improve memory. Flavanols extracted from cocoa beans had previously been found to improve neuronal connections in the dentate gyrus of mice.

A cocoa flavanol-containing test drink prepared specifically for research purposes was produced by the food company Mars, Incorporated, which also partly supported the research, using a proprietary process to extract flavanols from cocoa beans. Most methods of processing cocoa remove many of the flavanols found in the raw plant.

Flavanols are also found naturally in tea leaves and in certain fruits and vegetables, but the overall amounts, as well as the specific forms and mixtures, vary widely.

Source of this article: Enhancing dentate gyrus function with dietary flavanols improves cognition in older adults