Green tea works for memory

Memory is a whimsical thing. You can expunge that embarrassing, and slightly red wine fuelled, monologue on the evils of social media at last night’s dinner party from the memory banks. It is difficult though to erase the image of a middle-aged man jogging in lycra no matter how hard you try. Yes, memory is a fickle friend but most of us would generally like to have a memory that works at its best. Now a new study shows that a valuable ally in the quest to keep your memory at its peak is green tea.

Green tea is an increasingly popular drink. In the early 1990s global production of green tea stood at around 500,000 tonnes annually. Now it stands at around 1.2 million tonnes every year. Green tea is a significant and growing portion of the overall tea market and although it comes from the same plant as the black tea more commonly found in homes around the Western world it is distinctly different. Green tea leaves are picked and immediately sent to be dried or steamed to prevent fermentation, whereas black tea and other types are left to ferment after they are picked. The fermentation process leads to the breakdown of many of the antioxidant polyphenols in tea. Black tea retains many antioxidant properties but green tea is even stronger in this regard.

Over the years the antioxidant properties of green tea have seen it hailed for its many health benefits and now you can add “working memory” to the things that it can boost. Working memory is a system for temporarily storing and managing the information required to carry out complex cognitive tasks such as learning, reasoning, and comprehension. One test of working memory is memory span, the number of items, usually words or numbers, that a person can hold onto and recall. In a typical test of memory span, an examiner reads a list of random numbers aloud at about the rate of one number per second. At the end of a sequence, the person being tested is asked to recall the items in order. The average memory span for normal adults is 7 items.

In the new study healthy male subjects were given a drink containing three grams of green tea extract before being asked to solve working memory tasks. On another occasion they did similar tasks without the benefit of green tea. It emerged first of all that the subjects did better on the tasks when they had green tea. Secondly, MRI scans showed that green tea led to increased connectivity between the parietal lobe and frontal cortex of the brain. This increased connectivity would be behind the boost in working memory performance.

It seems then that green tea could be a useful way to enhance your working memory…provided you can remember to take it.