Study Shows Green Tea Extract Boosts Memory
Daily supplements of a green tea extract may boost mental al
ertness and enhance memory, according to a randomized, double-blind, placebo-controlled study from Korea.
A combination of a green tea extract with L-theanine was associated with improvements in immediate and delayed recall, and general memory, according to findings published in the Journal of Medicinal Foods.
“As a natural ingredient with a long history of consumption, LGNC-07 [ – a combination of green tea extract and L-theanine - ] should be considered as a potential nutraceutical candidate for enhancing cognitive performance,” wrote researchers.
The study was funded by Korea’s LG Household & Health Care, Ltd., which also produced the ingredient used in the study, and provided one of the co-authors for the paper.
Green tea
The majority of science on tea has looked at green tea, with benefits reported for reducing the risk of Alzheimer’s and certain cancers, improving cardiovascular and oral health, as well as aiding in weight management.
Green tea contains between 30 and 40 per cent of water-extractable polyphenols, while black tea (green tea that has been oxidized by fermentation) contains between 3 and 10 per cent. Oolong tea is semi-fermented tea and is somewhere between green and black tea. The four primary polyphenols found in fresh tealeaves are epigallocatechin gallate (EGCG), epigallocatechin, epicatechin gallate, and epicatechin.
The success has translated into a booming extract market, valued at a around $44m (€29.7m), according to recent report from Frost & Sullivan. The market is expected to grow by more than 13 per cent over the next seven years. Key players include DSM, Taiyo, and Tate & Lyle. Innovation in delivery has also seen companies like Maxx Performance release an encapsulated green tea extract for bakery applications.
L-theanine, an amino acid found in tea leaves, is thought to help reduce stress, promote relaxation and improve the quality of sleep. L-theanine is found in tea leaves in low concentrations (less than 2 percent), which means that effective dosage levels (of 100 – 200mg/day) cannot be delivered from drinking tea.
Study details
Ninety-one participants with mild cognitive impairment – a risk factor for Alzheimer’s disease – were recruited and randomly assigned to receive either 1,680 mg of the green tea extract-L-theanine combination (LGNC-07) or placebo (maltodextrin plus lactose) for 16 weeks.
A number of tests were used to assess memory and attention. Results showed that volunteers receiving the green tea supplement exhibited improvements in memory: ‘Marginal’ improvements were observed with regards to the delay in recognition, and ‘significant’ increases in memory regarding recall of word reading.
Electroencephalograms (EEG) were recorded in 24 volunteers, and these scans showed improvements in indicators of mental alertness in specific parts of the brain.
Listening to Music While Studying Impairs Performance
A study found that listening to background music while performing cognitive tasks – yes, kids, such as studying – impairs overall mental performance and ability to do arithmetic or recall information later.
The surprising aspect to the study findings is that the interference with mental ability and ability to recall remained strong even when the music being heard is among a person’s favorite music; same as listening to music the subject hated. Quiet produced the best recall performance.
The researchers stressed that music might have some generally beneficial effect on our health but only when one listens to it prior to – never while – performing mental tasks or memorizing material. This study will be published in the September 2010 issue of the journal, Applied Cognitive Psychology. It is available early to read online at http://bit.ly/aCr5GE.
