ココアを３か月 - Living, Loving, Thinking, Again

Stuart Clark “Chocolate component reverses memory loss in older people, claims study” http://www.theguardian.com/science/2014/oct/27/chocolate-component-reverses-memory-loss-older-people-claims-study

ココアや茶などに含まれるflavanolsという物質が記憶力の恢復に効く。コロンビア大学のScott A Small*1らの研究によれば、このflavanolsの濃度を特別に上げたココアを３か月間服用した60歳の被験者は30歳或いは40歳並みの記憶力を恢復したという。

Adam M Brickman, Usman A Khan, Frank A Provenzano, Lok-Kin Yeung, Wendy Suzuki, Hagen Schroeter, Melanie Wall, Richard P Sloan & Scott A Small”Enhancing dentate gyrus function with dietary flavanols improves cognition in older adults” http://www.nature.com/neuro/journal/vaop/ncurrent/full/nn.3850.html

要旨に曰く、

The dentate gyrus (DG) is a region in the hippocampal formation whose function declines in association with human aging and is therefore considered to be a possible source of age-related memory decline. Causal evidence is needed, however, to show that DG-associated memory decline in otherwise healthy elders can be improved by interventions that enhance DG function. We addressed this issue by first using a high-resolution variant of functional magnetic resonance imaging (fMRI) to map the precise site of age-related DG dysfunction and to develop a cognitive task whose function localized to this anatomical site. Then, in a controlled randomized trial, we applied these tools to study healthy 50–69-year-old subjects who consumed either a high or low cocoa–containing diet for 3 months. A high-flavanol intervention was found to enhance DG function, as measured by fMRI and by cognitive testing. Our findings establish that DG dysfunction is a driver of age-related cognitive decline and suggest non-pharmacological means for its amelioration.

但し普通のココアを飲んでも殆ど効果はないようだ。ココアを加工する過程でflavanolsは除去されてしまう。また、普通のチョコ・バーにおけるflavanolsの含有量はこの研究で使われた特制ココアの20分の１以下である；

Unfortunately guarding your memory is not as easy as remembering to eat more chocolate. Most methods of processing cocoa remove the flavanols. A typical chocolate bar contains about 40mg. The special drink used in the trial contained 900mg.
The drinks were prepared by chocolate manufacturer Mars Incorporated, who also partly funded the study. The Mars flavanol research programme began in the late 1980s to investigate the possible benefits to cardiovascular and cognitive health offered by the compounds.

それから、Small氏の所属は「アルツハイマー症研究センター」であるが、これが本格的な認知症 *2に効くかどうかは明らかでない。

*1:See http://www.cumc.columbia.edu/dept/sergievsky/fs/small.html