Chocolate—An Antidote to Age-related Memory Loss?

Martha Snyder Taggart, BrightFocus Editor, Science Communications
  • Science News
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Interesting Science at Your Fingertips

It may seem too good to be true, but your brain works better on chocolate, according to a small study just published online in the journal, Nature Neuroscience.

Dark chocolate, that is. Processing for milk chocolate gets rid of the helpful compounds.

Even though the study involved only 37 participants and was partly funded by the chocolate manufacturer Mars Inc. (as well as NIH and two foundations), it is getting headlines in The New York Times, The Washington Post, and the UK’s Guardian newspapers, among others. It’s being called a well-controlled, randomized trial done by experienced researchers.

For several decades, Mars has conducted a research program investigating the benefits of flavanols, antioxidant compounds in chocolate and other foods that are beneficial to health.

The findings:

  • After only three months, healthy people, ages 50 to 69, who drank a hot chocolate mixture high in flavanols performed better on a memory test than people who drank a low-flavanol mixture.
  • On average, the high-flavanol drinkers performed 25 percent better—equivalent to people two to three decades younger—on the study’s memory task, according to senior author Scott A. Small, MD, professor of neurology and director of the Alzheimer’s Disease Research Center at the Taub Institute at Columbia University Medical Center.
  • The findings support other research linking flavanols, and especially a purified form of cacao’s primary nutritional ingredient, known as epicatechin, to improved blood circulation, heart health, and memory in mice, snails and humans. One theory is that they improve brain blood flow; another is that they cause dendrites, message-receiving branches of neurons, to grow.
  • There also was increased function in an area of the brain’s hippocampus called the dentate gyrus, which has been linked to pattern recognition recall—a skill used in remembering where you parked the car or recalling faces of people you’ve just met.
  • Half of the participants in each study group also exercised four days a week, while half in each group remained sedentary. Surprisingly, exercise had no effects on memory in this study, whereas Small’s previous research found that exercise enhanced hippocampal function. This leads researchers to speculate that more vigorous exercise may be needed to affect older brains.

The caveats:

  • These findings do not apply to Alzheimer’s disease; there was no increased activity in a hippocampal region known as the entorhinal cortex, which is impaired early in Alzheimer’s disease. This suggests that age-related memory decline affects different parts of the brain than Alzheimer’s disease, and flavanols might not help Alzheimer’s, even though they might delay normal memory loss.
  • To get the full dose of epicatechin seen in the high-flavanol group (138 milligrams), you’d have to eat an awful lot of dark chocolate, about 300 grams—seven average-sized bars—a day, or 100 grams of baking chocolate or unsweetened cocoa powder. Milk chocolate won’t work because epicatechin is processed out of it.
  • While these results might seem like a dream-come-true—that you can eat a lot of candy bars, not exercise, and still reap the benefit—that’s probably not the case, nor a very good solution. To be validated, these results need to be replicated on a larger scale.

Glossary Terms

  • The hippocampus is a part of the brain that plays a significant role in the formation of long-term memories. The plural of hippocampus is hippocampi.