By Karen Weintraub
Special for USA TODAY
Though it may not justify your chocolate habit, early research suggests that cocoa may help improve blood flow to the brain in people with the earliest signs of vascular dementia.
In a small study out this week, people with high blood pressure, diabetes and some memory challenges performed better on cognitive tests after drinking hot cocoa for a month.
Drinking the cocoa also appeared to increase blood flow to their brains, according to ultrasounds. Vascular dementia, which can include confusion, trouble speaking and vision loss in addition to memory loss, is caused by reduced blood flow to the brain that deprives brain cells of oxygen and nutrients.
The study, published in the journal Neurology, was designed not to see whether doctors should be prescribing cocoa, but rather to test a potential new method for detecting vascular dementia early, before symptoms appear. And early signs are that it was a success.
"This is the first measure that could potentially identify individuals at risk before they develop the disease," said Farzaneh A. Sorond, a vascular neurologist at Brigham and Women's Hospital in Boston, who co-wrote the paper. "If we could find a way to identify them before they have damaged their neurons and blood vessels, potentially we could prevent this disease."
Two researchers who wrote an editorial commenting on the study agreed. The study, they wrote, "demonstrates the practical utility of a simple, inexpensive, and noninvasive technique" for measuring how much blood flow increases when the brain is active.
The study followed 80 people older than 60 with risk factors such as high blood pressure or diabetes. Both groups were told to drink two cups of hot cocoa a day.
Tests at the beginning of the trial revealed that about one-third of participants had early signs of memory problems. Those participants - but not the higher-functioning ones - showed improvements in brain blood flow and performance on cognitive tests after a month of cocoa.
The study was small and preliminary, so it should not encourage people to drink cocoa thinking it will save them from dementia, warned Heather Snyder, director of medical and scientific operations at the Alzheimer's Association.
"I don't think we can draw any conclusions from this study about whether drinking cocoa is a potential therapy," she said.
Sorond said it could be harmful if someone added cocoa to their diet without cutting calories elsewhere.
Each cup of cocoa used in the study contained 100 calories, so researchers were careful to ensure that participants cut 200 calories a day from their normal diet.
"I would be concerned if someone who already had a lot of vascular disease, diabetes, high blood pressure went out there and started taking in extra calories and fat and sugar," Sorond said. "That would probably be harmful to them."
Sorond said she personally will continue eating chocolate "in moderation, and not change my consumption as a result of this."