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."We're several steps removed from that
recommendation," said Dr Farzaneh Sorond, the study's lead author from
Brigham and Women's Hospital in Boston.
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: 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 recognise 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
"The next step is that we need a larger sample and we
need more people with impairment at baseline... (to) see if we can demonstrate
the same finding in a larger group," Sorond said.