米国神経学会（AAN）は8月7日、AANの機関誌であるNeurology誌オンライン版において、「比較的高齢の人々においては、1日2杯のホットココアの飲用が、脳の健康や思考技術を保つ上で有益である可能性がある」という研究所見を紹介した。
認知症のない平均年齢73歳の60人を対象としたこの研究では、参加者が1日2杯のホットココアを30日間にわたって飲み、記憶および思考技術の検査と、検査中の脳の血流量を測定するための超音波検査を受けた。
その結果、研究の開始時に血流障害が認められた18人では、研究の終了時までに、脳の作業領域における血流量が8.3％改善していた。これに対し、研究開始時に血流が正常であった参加者では、そうした改善は認められなかった。このほか、研究の開始時に血流障害が認められた参加者では、作業記憶についても、改善が認められた。
この研究では、参加者の半数は、抗酸化物質であるフラバノールを豊富に含有するホットココアを摂取し、残りの半数はフラバノール含有量の少ないホットココアを摂取したが、これらの群間に差異は認められなかった。
この研究文献への論説執筆者は、「ココアの摂取、血流障害、および認知機能の低下の間の関連性を明らかにするには、さらなる研究の実施が必要であるが、今回得られた研究所見は、今後の研究の指針を示す、重要な最初の一歩である」としている。
【関連リンク】
Chocolate May Help Keep Brain Healthy
Chocolate May Help Keep Brain Healthy
MINNEAPOLIS – Drinking two cups of hot chocolate a day may help older people keep their brains healthy and their thinking skills sharp, according to a study published in the August 7, 2013, online issue of Neurology®, the medical journal of the American Academy of Neurology. The study involved 60 people with an average age of 73 who did not have dementia. The participants drank two cups of hot cocoa per day for 30 days and did not consume any other chocolate during the study. They were given tests of memory and thinking skills. They also had ultrasounds tests to measure the amount of blood flow to the brain during the tests. “We’re learning more about blood flow in the brain and its effect on thinking skills,” said study author Farzaneh A. Sorond, MD, PhD, of Harvard Medical School in Boston and a member of the American Academy of Neurology. “As different areas of the brain need more energy to complete their tasks, they also need greater blood flow. This relationship, called neurovascular coupling, may play an important role in diseases such as Alzheimer’s.” Of the 60 participants, 18 had impaired blood flow at the start of the study. Those people had an 8.3-percent improvement in the blood flow to the working areas of the brain by the end of the study, while there was no improvement for those who started out with regular blood flow. The people with impaired blood flow also improved their times on a test of working memory, with scores dropping from 167 seconds at the beginning of the study to 116 seconds at the end. There was no change in times for people with regular blood flow. A total of 24 of the participants also had MRI scans of the brain to look for tiny areas of brain damage. The scans found that people with impaired blood flow were also more likely to have these areas of brain damage. Half of the study participants received hot cocoa that was rich in the antioxidant flavanol, while the other half received flavanol-poor hot cocoa. There were no differences between the two groups in the results. “More work is needed to prove a link between cocoa, blood flow problems and cognitive decline,” said Paul B. Rosenberg, MD, of Johns Hopkins School of Medicine in Baltimore, who wrote an editorial accompanying the study. “But this is an important first step that could guide future studies.” The study was supported by the National Institute on Aging and the National Heart, Lung, and Blood Institute. The cocoa was provided by Mars Inc. To learn more about brain health, please visit www.aan.com/patients.
The American Academy of Neurology, an association of more than 26,000 neurologists and neuroscience professionals, is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer’s disease, stroke, migraine, multiple sclerosis, concussion, Parkinson’s disease and epilepsy.
For more information about the American Academy of Neurology, visit http://www.aan.com or find us on Facebook, Twitter, Google+ and YouTube.
