A new research suggests that drinking cocoa every day may help older people keep their brains healthy.
A study of 60 elderly people with no dementia found two cups of cocoa a day improved blood flow to the brain in those who had problems to start with.
Those participants whose blood flow improved also did better on memory tests at the end of the study, the journal Neurology reported.
Experts said more research was needed before conclusions could be drawn.
It is not the first time cocoa has been linked with vascular health and researchers believe that this is in part due to it being rich in flavanols, which are thought to have an important role.
In the latest study, researchers asked 60 people with an average age of 73 to drink two cups of cocoa a day – one group given high-flavanol cocoa and another a low-flavanol cocoa – and consume no other chocolate.
Drinking cocoa every day may help older people keep their brains healthy
Ultrasound tests at the start of the study showed 17 of them had impaired blood flow to the brain.
There was no difference between those who drank flavanol-rich cocoa and those who had flavanol-poor cocoa.
But whichever drink they were given, 88% of those with impaired blood flow at the start of the study saw improvements in blood flow and some cognitive tests, compared with 37% of people whose blood flow was normal at the beginning of the study.
MRI scans in 24 participants found that people with impaired blood flow were also more likely to have tiny areas of brain damage.
“We’re learning more about blood flow in the brain and its effect on thinking skills,” said study author Dr. Farzaneh Sorond a neurologist at Harvard Medical School.
“As different areas of the brain need more energy to complete their tasks, they also need greater blood flow. This relationship, called neurovascular coupling, may play an important role in diseases such as Alzheimer’s.”
The researchers said the lack of difference between the flavanol-rich and flavanol-poor cocoa could be because another component of the drink was having an effect or because only small amounts were needed.
An analysis of 20 studies showed that eating dark chocolate daily resulted in a slight reduction in blood pressure.
The Cochrane Group’s report said chemicals in cocoa, chocolate’s key ingredient, relaxed blood vessels.
However, there are healthier ways of lowering blood pressure.
The theory is that cocoa contains flavanols which produce a chemical in the body called nitric oxide. This “relaxes” blood vessels making it easier for blood to pass through them, lowering the blood pressure.
An analysis of 20 studies showed that eating dark chocolate daily resulted in a slight reduction in blood pressure
However, studies have thrown up mixed results. The Cochrane analysis combined previous studies to see if there was really an effect.
There was a huge range in the amount of cocoa consumed, from 3 g to 105 g a day, by each participant. However, the overall picture was a small reduction in blood pressure.
A systolic blood pressure under 120 mmHg (millimetres of mercury) is considered normal. Cocoa resulted in a 2-3 mmHg reduction in blood pressure. However, the length of the trials was only two weeks so the longer term effects are unknown.
Lead researcher Karin Ried, from the National Institute of Integrative Medicine in Melbourne, Australia, said: “Although we don’t yet have evidence for any sustained decrease in blood pressure, the small reduction we saw over the short term might complement other treatment options and might contribute to reducing the risk of cardiovascular disease.”
High blood pressure is both common and deadly. It has been linked to 54% of strokes worldwide and 47% of cases of coronary heart disease.
However, chocolate packs plenty of fat and sugar as well as cocoa so is not the ideal way of lowering blood pressure.
There has also been a warning in the Lancet medical journal that dark chocolate may contain fewer flavanols than you might think. Dark chocolate contains a higher cocoa count than milk chocolate so should contain more flavanols, however, they can also be removed as they have a bitter taste.