Dark Chocolate May Guard Against Brain Injury from Stroke

Science Daily reported May 5, 2010 that Researchers at Johns Hopkins discovered a compound in dark chocolate may protect the brain after a stroke by increasing cellular signals already known to shield nerve cells from damage.

The study involved feeding mice epicatechins (a compound found naturally in cold pressed dark chocolate) and inducing strokes in their brains. The scientists found that the animals that had eaten the epicatechin suffered significantly less brain damage than the ones that had not been given the compound.

It seems like it worked best when the dark chocolate compound epicatechins were eaten first, but also worked up to 3 and a half hours after the stroke. While most treatments against stroke in humans have to be given within a two to three hour time window to be effective, epicatechin appeared to limit further neuronal damage when given to mice 3.5 hoursafter a stroke.

Professors at the Johns Hopkins University School of Medicine, say the 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 are activated. In mice that selectively lacked activity in those pathways, the study found, epicatechin had no significant protective effect and their brain cells died after a stroke.

The study now appears online in the Journal of Cerebral Blood Flow and Metabolism.

Eventually, this research into these pathways could lead researchers to insights into limiting acute stroke damage and possibly protecting against chronic neurological degenerative conditions, such as Alzheimer's disease and other age-related cognitive disorders.

The amount of dark chocolate people would need to consume to benefit from its protective effects remains unclear, since this has not been studied in clinical trials. It is also not a free pass to go out and consume large amounts of chocolate, which normally is high in calories and fat. In fact, people should be reminded to eat a healthy diet with a variety of fruits and vegetables.

This chocolate was high in the compound epicatechin, which is a flavanol, a flavanoid-related compound. Not all dark chocolates are created equally, Sylvain Doré, Ph.D., associate professor of anesthesiology and critical care medicine and pharmacology and molecular sciences cautions. Some have more bioactive epicatechin than others.

Not all dark chocolates are created equally, he cautions. Some have more bioactive epicatechin than others.

"The epicatechin found in dark chocolate is extremely sensitive to changes in heat and light" he says. "In the process of making chocolate, you have to make sure you don't destroy it. Only a few chocolates have the active ingredient. The fact that it says 'dark chocolate' is not sufficient."