NEW YORK (Reuters Health) - Older people with impaired blood flow to their brains saw improvements in thinking skills after drinking two cups of cocoa every day for a month, in a new study.
The study's researchers caution, however, that people shouldn't start stocking up on hot chocolate mix to help solve their crossword puzzles based on the new finding.
Instead, Sorond said the result helps focus future research that may turn up which component or components of hot chocolate are linked to better thinking skills.
Previous research has found the brain is more active if it gets an adequate supply of oxygen and sugar from the blood, the researchers wrote in the journal Neurology.
Among people with certain diseases that affect blood vessels - such as high blood pressure and diabetes - blood flow to the brain may be impaired.
Sorond and her colleagues wanted to look at whether drinking hot chocolate rich in flavanols could improve thinking skills in those people.
Studies have found that eating chocolate containing the plant compounds is linked to lower blood pressure readings and fewer strokes (see Reuters Health stories of Oct 10, 2011 and Aug 14, 2012 here: http://reut.rs/19NXUdo and http://reut.rs/QzBg9E.)
For the new study, the researchers recruited 60 people who were an average of 73 years old to be separated into one of two groups.
People in one group were told to drink two cups of flavanol-rich hot chocolate every day for one month. Those in the other group drank low-flavanol hot chocolate. All participants were told to not eat or drink any other chocolate during the study period.
There were no differences in blood flow or in scores on thinking tests between the two hot chocolate groups at the start of the study or after one month. So the researchers combined both cocoa groups and compared people with poor blood flow to the brain at the start of the study to those who had adequate blood flow.
They found more people with poor blood flow at the start saw their circulation improve by the end, compared to people who had adequate blood flow initially.
Also, while those with adequate blood flow didn't see a significant improvement on tests that measured their thinking skills, the 17 people in the impaired flow group did.
Among those people, the time it took to connect sequential dots on pieces of paper or recognize certain characters on computer screens fell from 167 seconds at the start of the study to 116 seconds at the end.
Sorond said that time can add up for people during the day.
"That's important if you add it to everything that requires multitasking for us," she said.
It's possible that even small amounts of flavanols make a difference for people with impaired blood flow, Sorond said, or that the caffeine in cocoa played a role in their improvement.
She warned, however, that the new study cannot prove drinking hot chocolate boosted thinking or blood flow.
"The next step is that we need a larger sample and we need more people with impairment at baselineâ¦ (to) see if we can demonstrate the same finding in a larger group," Sorond said.
SOURCE: http://bit.ly/JOxTg9 Neurology, online August 7, 2013.