Can a Cocoa a Day Keep Dementia at Bay?

Daily cocoa drinking had little effect on cognitive function for healthy participants

/ Author:  / Reviewed by: Robert Carlson, M.D Beth Bolt, RPh

(RxWiki News) A cup of hot cocoa sounds delightful during the cold days of winter. It might perk you right up like a cup of coffee. But does it make a difference to your brain?

A recent study found that two daily cups of cocoa led to small improvements on brain tests for seniors who already had some brain impairment.

For seniors with healthy brain functioning, however, the cocoa did not appear to make much difference.

The improvements in those who had some impairments were small and only on certain measures. It's not clear if daily cocoa would help reduce dementia risk in the long-term.

"Ask your doctor about a healthy diet for your brain."

This study, led by Farzaneh A. Sorond, MD, PhD, of the Department of Neurology at Brigham and Women's Hospital in Boston, looked at the possible influence of cocoa on seniors' cognitive functioning.

The researchers studied 60 seniors, with an average age of 73, who had high blood pressure and/or type 2 diabetes that were both well managed, with or without medication.

The participants were split into two groups that both drank two cocoa drinks every day for 30 days.

One of the cocoa drinks was rich in flavanols (609 mg), and the other had very little flavanols (13 mg) in it.

Flavanols are the nutrients found in the cocoa bean (and in chocolate) that are thought to be good for human health. They are also found in certain fruits and vegetables.

Neither the participants nor the researchers providing them with the cocoa knew whether it was the high- or low-flavanols drink.

The participants were advised to remove items from their daily diet to account for the extra 200 calories of the cocoa drinks. They were also instructed not to eat other chocolate during the study or to drink caffeine on the days they were tested.

Before the trial began, the speed of participants' blood flow to the brain was studied, and their blood pressure was measured.

They also took three tests to measure their cognitive function. One was the Mini-Mental State Examination, a standard questionnaire used to measure cognitive impairment (problems with memory, thinking, language and judgement).

The other two tests were "trail-making tests" that measure a person's cognitive skills with a task connecting dots as quickly as possible.

The speed of blood flow to the brain and the mental tests were given to the participants on the first and second days of the trial and on the 30th day.

After the 30 days, the researchers compared results between the groups. The results did not show major differences between the group drinking flavanol-rich cocoa and those drinking the flavanol-poor cocoa.

The results also did not show any differences among any of the participants on the Mini-Mental State Examination.

A small amount of improvement was seen in two measures for the participants who had some damage to their cognitive functioning at the start of the study.

These improvements were small and occurred with both types of cocoa drinks. It's also not clear how significant they are overall to a person's mental functioning.

Drinking either of the cocoa drinks appeared to improve the neurovascular coupling of the participants who had some cognitive impairment at the start of the study.

Neurovascular coupling means that a person's blood flow to the brain is linked to changes in their brain activity. An increase means improved cognitive function.

The researchers also found that those with higher neurovascular coupling had less damage to the white matter in their brains.

Among the participants who had poor neurovascular coupling at the start of the study, their coupling improved 10.6 percent by day 30.

However, the cocoa did not make a difference for those who already had healthy neurovascular coupling.

In addition, among the participants who already had some impaired cognitive function at the start of the study, the cocoa appeared to improve their performance on one of the trail-making tests.

Before the cocoa, they took an average 167 seconds to complete it. After 30 days of cocoa, they took an average 116 seconds. This improvement occurred regardless of which cocoa drink they had.

There was no control group to compare the participants to since this improvement included all the participants drinking any cocoa at all. It's not possible to know from this study if that improvement would have happened on its own without drinking cocoa.

Overall, then, drinking cocoa appears that it might have made a small difference in improving the brain functioning of those who had some impairment to start with.

Among those with healthy brains at the start of the study, drinking cocoa did not make much difference in their cognitive function.

This study was published August 7 in the journal Neurology. The research was funded by the National Institute on Aging and the National Heart, Lung and Blood Institute.

The cocoa was provided by Mars Inc. One author has received funds from Biogen Idec. No other potential conflicts of interest were reported.

Review Date: 
August 6, 2013
Last Updated:
August 8, 2013