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A bite to remember? Chocolate is shown to aid memory

Science edged closer on Sunday to showing that an antioxidant in chocolate appears to improve some memory skills that people lose with age.

In a small study in the journal Nature Neuroscience, healthy people, ages 50 to 69, who drank a mixture high in antioxidants called cocoa flavanols for three months performed better on a memory test than people who drank a low-flavanol mixture.

On average, the improvement of high-flavanol drinkers meant they performed like people two to three decades younger on the study’s memory task, said Dr. Scott A. Small, a neurologist at Columbia University Medical Center and the study’s senior author. They performed about 25 percent better than the low-flavanol group.

“An exciting result,” said Craig Stark, a neurobiologist at the University of California, Irvine, who was not involved in the research. “It’s an initial study, and I sort of view this as the opening salvo. And look, it’s chocolate. Who’s going to complain about chocolate?”

The findings support recent research linking flavanols, especially epicatechin, to improved blood circulation, heart health and memory in mice, snails and humans. But experts said the new study, although involving only 37 participants and partly funded by Mars Inc., the chocolate company, goes further and was a well-controlled, randomized trial led by experienced researchers.

Besides improvements on the memory test — a pattern recognition test involving the kind of skill used in remembering where you parked the car or recalling the face of someone you just met — researchers found increased function in an area of the brain’s hippocampus, which has been linked to this type of memory.

But don’t rush out to buy candy bars. To consume the high-flavanol daily dose of epicatechin, you’d have to eat at least 300 grams of dark chocolate a day — about seven average-sized bars. Milk chocolate has most epicatechin processed out of it.

The Columbia study had important limitations. For example, the only daily dietary requirements were either 900 milligrams of flavanols with 138 milligrams of epicatechin or 10 milligrams of flavanols with less than 2 milligrams of epicatechin, so participants could have eaten other things that played a role. And while researchers also had half of the healthy but sedentary participants in each group exercise four days a week, surprisingly, the exercise had no memory or brain effects.

More extensive research is planned. As for why flavanols would help memory, one theory is that they improve brain blood flow; another, favored by Small, is that they cause dendrites, message-receiving branches of neurons, to grow.