A compound found in dark chocolate may protect the brain after a stroke by increasing the brain’s cellular signals, which are known to shield nerve cells from damage.
The compound, epicatechin, which occurs naturally in cocoa and tea, was tested on laboratory mice by researchers at the Johns Hopkins University School of Medicine Anesthesiology and Critical Care Department. The mice were then subjected to induced strokes and their brains examined.
The research, by Associate Professor Sylvain Doré and his team was published in the May 5, 2010 online edition of the Journal of Cerebral Blood Flow and Metabolism.
Epicatechin Protected Mouse Brains After Stroke
Dr. Doré and his researchers fed the lab mice small doses of pure epicatechin – 5mg, 15mg or 30 mg per kilogram of the mouse’s weight, before inducing strokes in the animals by briefly cutting off the blood supply to their brains.
They found that the mice which were given the largest doses of epicatechin had the least damage to their neurons compared to similar mice which had not been dosed with the compound.
However, even the mice that only received 5mg/kg of epicatechin showed significantly smaller brain infarcts and decreased neurological deficit scores (damage from stroke) than the untreated mice.
Panamanian Indians Experienced Epicatechin’s Cardio-protection
The cardiovascular-protective power of epicatechin was discovered by scientists researching a group of Panamanian Indians who lived on isolated islands. These Kuna Indians had a very low incidence of heart disease or stroke, despite being genetically similar to Indians living in other parts of Panama.
When the Kuna Indians moved away from their islands, they soon developed similar levels of cardiovascular disease as their countrymen. The difference was found to be a protective factor in their island diet – a dark, bitter chocolate beverage, which they drank instead of coffee or soda.
The drink turned out to be high in the flavonol, epicatechin, found in cocoa, and in lesser amounts in tea.
Stroke Protection from Epicatechin Less Time-critical than Other Methods
Dr. Doré’s team found that providing epicatechin to the mice after they had suffered a stroke was not as time-critical as most stroke treatments are. For people, the first couple of hours after a stroke are critical, with medication needing to applied as soon as possible. After two hours, most stroke medications cannot prevent further damage to brain cells.
For the mice with induced brain infarcts, however, epicatechin appeared to limit further neuronal damage when given as late as three and a half hours after the stroke.
Epicatechin Acts on Neuronal Pathways in the Brain
The way epicatechin protects the brain after a stroke is connected to how it acts on two specific neuronal pathways in the brain, Dr. Doré said.
“This study suggests that epicatechin stimulates two previously well-established pathways known to shield nerve cells in the brain from damage. When the stroke hits, the brain is ready to protect itself because these pathways — Nrf2 and heme oxygenase 1 — are activated,” he said.
Although the compound has only been trialed on mice so far, Dr. Doré hopes his research into these pathways could lead to advances in limiting acute stroke damage and possibly protecting against chronic neurological degenerative conditions, such as Alzheimer’s disease and other age-related cognitive disorders.
Is Eating Chocolate the Way to Prevent Strokes?
While the Kuna Indians protected their hearts and circulatory systems by drinking large amounts of a chocolaty beverage, Dr. Doré warned that eating large amounts of dark chocolate might not be a good cardio-protective measure.
People shouldn’t take his research into epicatechin as a free pass to go out and consume large amounts of chocolate, which is high in calories and fat, he said, In fact, they should be reminded to eat a healthy diet with a variety of fruits and vegetables.
However, other research has shown some cardio-protective benefits from eating small amounts of high quality dark chocolate or drinking cocoa. It’s possible to enjoy small quantities of dark chocolate or a cocoa drink as a treat to complement a healthy diet, and gain potential additional cardiovascular benefits.
For more on chocolate and cocoa you might like to read Chocolate Could Protect Against Heart Attacks, Hot Cocoa’s Antioxidant Power and Mayans Sought Wine Not Chocolate.
Sue Cartledge - I'm a science, health, nutrition and lifestyle journalist, fascinated by the way the physical world operates in all its forms, and how ...
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