August 8, 2013
Chocolate Boosts Cognitive Abilities In Older Adults
Brett Smith for redOrbit.com - Your Universe Online
The 60 study volunteers, who averaged around 73 years old, were told not to consume any other chocolate during the study and underwent brain imaging scans to determine the amount of blood flow to the brain during the cognitive tests.
The study was based on previous research that found eating chocolate varieties high in the antioxidant flavanol was affiliated with higher brain and blood vessel functioning. Volunteers were arbitrarily assigned to drink either flavanol-rich or flavanol-poor hot chocolate during the month-long study period.
"We're learning more about blood flow in the brain and its effect on thinking skills," said Dr. Farzaneh A. Sorond, a neurologist from Harvard and co-author of the latest study. "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."
Out of 60 study participants, 18 had signs of impaired blood flow at the study's outset. At the end of the study, this group showed an 8.3 percent expansion in the blood flow to the working areas of the brain. Those who had no signs of impaired blood flow at the beginning of the study showed no signs of improvement.
The impaired blood flow group also improved their performance on a working memory test, involving the ability to spot patterns in a series of letters being shown on a computer display. Scores from this group fell from 167 seconds at the study's outset to 116 seconds by the end of the study. Once again, the 'normal' blood flow group showed no significant change.
Contrary to expectations, the researchers were not able to find significant differences between the flavanol-rich and flavanol-poor groups. The team said future studies should be focused on finding out what cause these improvements on a molecular level.
"More work is needed to prove a link between cocoa, blood flow problems and cognitive decline," said Dr. Paul B. Rosenberg, an Alzheimer's expert at Johns Hopkins School of Medicine who wrote an editorial accompanying the study. "But this is an important first step that could guide future studies."
Research on Alzheimer's has intensified in recent years, and Sorond suggested to the Los Angeles Times that scientists should focus more on preventing cognitive decline and less on curing it.
"By the time people develop these problems, it's too late to initiate the drugs we have," she said. If we could diagnose them earlier, before they have clinical symptoms, using physiological markers ... maybe we could prevent the disease or lessen its impact."