Cocoa
Cocoa is made from the beans of the cocoa tree (theobroma cocao) and is the main ingredient used to make chocolate. Recently it has come under the research spotlight because of its very high antioxidant profile and it support of heart and cardiovascular health. Because cocoa is already a commonly used food with a very long history of use, studies in humans have been easy to do without fear of dangerous or unknown side effect. Hence the majority of studies into cocoa's ability to enhance cognition have occurred in humans. What is clear from the studies is that cocoa consumption improves cognition acutely in both healthy and elderly participants. Its likely method of action is via improved blood flow and delivery and possibly its action as an antioxidant. The effects of chronic administration on cognition are inconclusive at this stage with some studies showing improvements while others showing no effect.
Most beneficial for - anyone wanting to improve memory
Effective dose - 500-1000mg polyphenols from chocolate or raw cocoa
Length of action - immediate improvements
Safety - extremely safe (common food ingredient)
Type cognition effected - mental fatigue, visual functions, spacial memory,
Enhancers - not known
Supporting Human Studies
Consumption of cocoa flavanols results in acute improvements in mood and cognitive performance during sustained mental effort (Scholey et al, 2010)
In this randomised double blind placebo controlled study 30 healthy individual consumed a drink with either 520mg, 994mg or no mg of cocoa flavanols. A battery of cognitive tests were performed shortly after ingestion of the drinks. Both groups receiving the flavanols showed improvements in cognitive tasks compared to the control group. The group receiving the higher dosage showed further improvements of speed in a rapid visual information processing test compared to both other groups. Only the 520mg group showed improvement in mental fatigue assessments.
Consumption of cocoa flavanols results in an acute improvement in visual and cognitive functions (Field et al, 2011)
In this randomized single blind crossover study 30 healthy young adults received 720mg of cocoa polyphenols in chocolate daily or none in a white chocolate control over one week. Both visual and cognitive tests were performed at the end of the week. The consumption of cocoa polyphenols was shown to significantly improve visual contrast sensitivity and reduce the time required to detect motion direction. It was also shown to improve spacial memory and some aspects of a choice reaction time task.
The Effect of Flavanol-rich Cocoa on the fMRI Response to a Cognitive Task in Healthy Young People (Francis et al, 2006)
Sixteen healthy young subject were put in an fMRI machine to measure blood flow to different parts of the brain. Subjects were given 150mg of cocoa flavanols over the 5 previous days. This resulted in increased blood flow to parts of the brain while doing a cognitive task compared to the same cognitive task without the cocoa supplementation. A single 450mg dose of cocoa flavanols was also tested for blood flow to the brain. It was also shown also to improve blood flow to the brain.
Cerebral blood flow response to flavanol-rich cocoa in healthy elderly humans (Farzenah et al, 2008)
Thirty four healthy older adults received a cocoa drink that was either rich or poor in flavanols. Ultrasound was then used to examine blood flow through their brains. The group receiving the flavanol rich drink daily at the end of two weeks showed an average 10% increase in blood flow to the brain a compared the flavanol poor group.
Intake of Flavonoid-Rich Wine, Tea, and Chocolate by Elderly Men and Women Is Associated with Better Cognitive Test Performance (Nurk et al, 2009)
Elderly participants (70-74 years, 2031 of them) from norway underwent cognitive tests and answered questionnaires about there dietary habits. Participants consuming chocolate, wine or tea had significantly better score on cognition tests than those not consuming these foods. Those consuming all three had the highest cognitive scores. The higher the consumption of each generally the better test scores.
Supporting Animal Studies
Effects of long-term administration of a cocoa polyphenolic extract (Acticoa powder) on cognitive performances in aged rats (Bisson et al, 2008)
Aged rats received 24mg/kg of a cocoa extract (high in polyphenols) for 12 months or the same diet without the extract. Results showed after 12 months that the group taking the cocoa extract had improved cognition in light extinction and water maze tests and increased lifespan compared to the control group.
Preventive Antioxidant Effects of Cocoa Polyphenolic Extract on Free Radical Production and Cognitive (Rozan et al, 2007)
Rats were given a cocoa extract, vitamin E or no supplement for 14 days prior to undergoing a heat treatment designed to produce cognitive impairments. Those rats consuming the cocoa extract or vitamin E before heat treatment performed significantly better on cognitive tests such as a water maze and light extinction paradigm than control rats. The antioxidant effect is believed to be part of the reason for this observation.Performances after Heat Exposure in Wistar Rats
Supporting Cellular Studies
None
Contradictory Studies
A double-blind, placebo-controlled, randomized trial of the effects of dark chocolate and cocoa on variables associated with neuropsychological functioning and cardiovascular health: clinical findings from a sample of healthy, cognitively intact older adults (Crews et al, 2008)
In the double blind placebo controlled trial 101 adults received either 37g of dark chocolate and 8 ounces of a cocoa drink or placebo chocolate and drink daily for 6 weeks. No differences were found in neuropsycological, haematological or blood pressure variables between groups. In a questionnaire after the study more than half of the participants in both groups could correctly identify which group they belonged to.
Combinational Studies
None
Safety Studies
None
Most beneficial for - anyone wanting to improve memory
Effective dose - 500-1000mg polyphenols from chocolate or raw cocoa
Length of action - immediate improvements
Safety - extremely safe (common food ingredient)
Type cognition effected - mental fatigue, visual functions, spacial memory,
Enhancers - not known
Supporting Human Studies
Consumption of cocoa flavanols results in acute improvements in mood and cognitive performance during sustained mental effort (Scholey et al, 2010)
In this randomised double blind placebo controlled study 30 healthy individual consumed a drink with either 520mg, 994mg or no mg of cocoa flavanols. A battery of cognitive tests were performed shortly after ingestion of the drinks. Both groups receiving the flavanols showed improvements in cognitive tasks compared to the control group. The group receiving the higher dosage showed further improvements of speed in a rapid visual information processing test compared to both other groups. Only the 520mg group showed improvement in mental fatigue assessments.
Consumption of cocoa flavanols results in an acute improvement in visual and cognitive functions (Field et al, 2011)
In this randomized single blind crossover study 30 healthy young adults received 720mg of cocoa polyphenols in chocolate daily or none in a white chocolate control over one week. Both visual and cognitive tests were performed at the end of the week. The consumption of cocoa polyphenols was shown to significantly improve visual contrast sensitivity and reduce the time required to detect motion direction. It was also shown to improve spacial memory and some aspects of a choice reaction time task.
The Effect of Flavanol-rich Cocoa on the fMRI Response to a Cognitive Task in Healthy Young People (Francis et al, 2006)
Sixteen healthy young subject were put in an fMRI machine to measure blood flow to different parts of the brain. Subjects were given 150mg of cocoa flavanols over the 5 previous days. This resulted in increased blood flow to parts of the brain while doing a cognitive task compared to the same cognitive task without the cocoa supplementation. A single 450mg dose of cocoa flavanols was also tested for blood flow to the brain. It was also shown also to improve blood flow to the brain.
Cerebral blood flow response to flavanol-rich cocoa in healthy elderly humans (Farzenah et al, 2008)
Thirty four healthy older adults received a cocoa drink that was either rich or poor in flavanols. Ultrasound was then used to examine blood flow through their brains. The group receiving the flavanol rich drink daily at the end of two weeks showed an average 10% increase in blood flow to the brain a compared the flavanol poor group.
Intake of Flavonoid-Rich Wine, Tea, and Chocolate by Elderly Men and Women Is Associated with Better Cognitive Test Performance (Nurk et al, 2009)
Elderly participants (70-74 years, 2031 of them) from norway underwent cognitive tests and answered questionnaires about there dietary habits. Participants consuming chocolate, wine or tea had significantly better score on cognition tests than those not consuming these foods. Those consuming all three had the highest cognitive scores. The higher the consumption of each generally the better test scores.
Supporting Animal Studies
Effects of long-term administration of a cocoa polyphenolic extract (Acticoa powder) on cognitive performances in aged rats (Bisson et al, 2008)
Aged rats received 24mg/kg of a cocoa extract (high in polyphenols) for 12 months or the same diet without the extract. Results showed after 12 months that the group taking the cocoa extract had improved cognition in light extinction and water maze tests and increased lifespan compared to the control group.
Preventive Antioxidant Effects of Cocoa Polyphenolic Extract on Free Radical Production and Cognitive (Rozan et al, 2007)
Rats were given a cocoa extract, vitamin E or no supplement for 14 days prior to undergoing a heat treatment designed to produce cognitive impairments. Those rats consuming the cocoa extract or vitamin E before heat treatment performed significantly better on cognitive tests such as a water maze and light extinction paradigm than control rats. The antioxidant effect is believed to be part of the reason for this observation.Performances after Heat Exposure in Wistar Rats
Supporting Cellular Studies
None
Contradictory Studies
A double-blind, placebo-controlled, randomized trial of the effects of dark chocolate and cocoa on variables associated with neuropsychological functioning and cardiovascular health: clinical findings from a sample of healthy, cognitively intact older adults (Crews et al, 2008)
In the double blind placebo controlled trial 101 adults received either 37g of dark chocolate and 8 ounces of a cocoa drink or placebo chocolate and drink daily for 6 weeks. No differences were found in neuropsycological, haematological or blood pressure variables between groups. In a questionnaire after the study more than half of the participants in both groups could correctly identify which group they belonged to.
Combinational Studies
None
Safety Studies
None