Chocolate Shown to Improve Mood and Brain Function

Cocoa Flavanol Consumption Improves Cognitive Performance and Mood in Young Adults

Flavonoids are a type of natural compound found in many of the plant foods that we eat, including grapes, apples, green and black tea, and cocoa — plus cocoa-containing food products such as dark chocolate.

The benefits of consuming flavanoids have captured the attention of researchers in recent years. Known benefits include a reduction in platelet aggregation and improvements in insulin sensitivity and blood pressure. In addition, a particular variety of flavanoid found in cocoa — the "cocoa flavanol (CF)" — has been found to increase cerebral blood flow and brain activity.

In the study to be discussed here, researchers set out to evaluate subjects who were asked to perform a challenging mental task so as to determine if CF consumption had an impact on cognitive performance and mental fatigue.

Conducted at the the Brain, Performance and Nutrition Research Centre at Northumbria University UK, the double-blind, placebo-controlled, crossover study had participants consume cocoa drinks that contained varying amounts of CF while assessing cognition and mood. Participants consisted of 30 healthy, nonsmoking students with a mean age of 22.

The test was performed over three days. Subjects abstained from all caffeine and cocoa-containing foods for at least 12 hours before the test began. On each of the three days, the students were asked to drink 1-3 of the cocoa drinks, each of which contained either 46 mg, 520 mg, or 994 mg of the CF.

Participants took the State-Trait Anxiety Inventory (STAI) self-exam, which assesses anxiety level, both before and after drinking the cocoa drinks. Study coordinators administered the Cognitive Demand Battery (CDB) test, which assesses cognition and mood, at 10 minute intervals for one hour beginning 90 minutes after beverage consumption. (The CDB creates a mentally demanding scenario via subjecting participants to mathematical subtraction tests and rapid visual information processing tasks.) A visual analogue scale was also used to evaluate mental fatigue 1 minute after the test.

Results

The tests revealed a significantly higher performance level (i.e., fewer errors) in the CDB test results for those who consumed the 520 CF and 994 CF drinks. And these heightened performance levels were measured as sustained through up to 40 minutes after the CF consumption. Rapid visual processing was also measured to be improved in subjects who consumed the 994 CF drinks. Mental fatigue was measured as lower in subjects who drank the 520 CF drinks.

Researchers concluded that acute CF consumption improves cognitive function and lowers mental fatigue in young adults.

Reference

Scholey AB, French SJ, Morris PJ, Kennedy DO, Milne AL, Haskell CF. "Consumption of cocoa flavanols results in acute improvements in mood and cognitive performance during sustained mental effort." J Psychopharm. 2009. [epub ahead of print]. DOI: 10.1177/0269881109106923.