Nov. 24 (UPI) -- Flavanol-rich cocoa drinks can improve brain oxygenation and cognitive performance in healthy adults, a new study finds.
Researchers tested the impact of intake of cocoa flavanols in a two-trial study published Tuesday in Scientific Reports.
Subjects were given flavanol-rich cocoa in one trial and consumed processed cocoa with very low levels of flavanols in another trial. Neither the researchers nor participants knew which type of cocoa was consumed in the double blind study, to prevent expectations from affecting the results.
The high flavanol cocoa intake led to faster and greater brain oxygenation in 14 of 18 male adults, ages 18-45, along with better performance on complex tests, researchers found.
"Flavanols are small molecules found in many fruits and vegetables, and cocoa, too," Catarina Rendeiro, one of the study's lead researchers, said in a press release.
"They give fruits and vegetables their bright colors, and they are known to benefit vascular function. We wanted to know whether flavanols also benefit the brain vasculature, and whether that could have a positive impact on cognitive function," said Rendeiro, a biologist at the University of Birmingham in Britain.
Rendeiro added that the four adults who did not show improvement with flavanol intake "already had the highest oxygenation responses at baseline."
"This may indicate that those who are already quite fit have little room for improvement," Rendeiro said. "Overall, the findings suggest that the improvements in vascular activity after exposure to flavanols are connected to improvement in cognitive function."
Rendeiro led the research along with University of Illinois at Urbana-Champaign psychology professors Monica Fabiana and Gabriel Gratton.
Fabiana said the team measured oxygenation in the frontal cortex, which is key in planning, regulating and decision-making, with a technique that uses light to capture changes in blood flow to the brain.
Limitations of the study, which included 18 healthy male volunteers, included the low number of participants and exclusion of females, the researchers said.
"Females were excluded from the study to ensure a more homogenous sample and to minimize the impact of hormonal fluctuations during the menstrual cycle on vascular outcomes," researchers said in the study.