Testing chocolate’s effect on mind and mood

In the study, 72 people were divided into three groups and given drink mixes providing 20 grams of dark chocolate every day for 30 days. The drink mixes given to the groups had different amounts of cocoa polyphenols:

• the high-polyphenol drink mix had 500 mg of cocoa polyphenols per daily serving;
• the low-polyphenol drink mix had 250 mg of cocoa polyphenols per daily serving; and,
• the control drink had none.

Cognitive tests and mood surveys were given to the participants at the beginning and end of the study. In addition, these same tests were used 1, 2.5, and 4 hours after each person took their first chocolate drink to see if there were immediate changes.

High-polyphenol chocolate soothes emotions

These were the results of the study:

• There were no immediate changes in cognitive test or mood survey scores in any of the groups after a single chocolate drink serving.
• The people using the high-polyphenol drink had better mood scores at the end of the study, with increases in particular in calmness and contentedness, but there were no mood changes in the low-polyphenol or the control group.
• There were no changes in cognitive function in any group during the study.

“This randomized controlled trial is perhaps the first to demonstrate the positive effects of cocoa polyphenols on mood in healthy participants,” the study’s authors said. “This provides a rationale for exploring whether cocoa polyphenols can ameliorate the symptoms associated with clinical anxiety or depression.”

Eat a polyphenol-rich diet

Antioxidant plant polyphenols are often marketed as anti-aging nutrients. The polyphenols in cocoa are mainly of a type known as catechins and are similar to those found in green tea and red wine. Dark chocolate is one of the richest sources of polyphenols, and the 20 gram (3/4 ounce) portion used in this study would typically have 200 to 400 mg of polyphenols. Milk chocolate might not have the same properties as dark chocolate because milk proteins tend to bind to polyphenols and reduce their absorption.

The health benefits of eating polyphenol-rich foods are still coming to light, but appear to include heart disease and cancer prevention, as well as improved mood. Here are some ways to boost your polyphenol intake:

• Have a cup of tea. A cup of green tea has approximately 266 mg of polyphenols. Black tea has almost as much. Have it without milk for the best effect.
• An apple a day. A single apple has about 200 mg of polyphenols. Other fruits like berries, cherries, plums, and melon are also good sources.
• Chocolate as medicine. An ounce and a half of dark chocolate each day will give you approximately the polyphenol amount that was associated with enhanced calmness and contentment in this study.

(J Psychopharmacol 2013;27:451–8)