Epigallocatechin gallate, caffeine, and L-theanine all may work to improve brain function and health.The amount of caffeine found in Green Tea 3505 is enough to help improve memory and reaction time, as well as to boost dopamine and norepinephrine in the brain.In a clinical trial on 12 healthy volunteers, green tea extract improved brain activity in a key region to working memory processing (dorsolateral prefrontal cortex). Green tea increased brain activity, especially theta waves, in another study on 8 healthy volunteers. This suggests its potential to improve alertness and attention. L-theanine especially increased alpha waves, associated with mental alertness and arousal, in another trial on 35 healthy people.A combination of green tea extract and L-theanine improved memory and attention in a clinical trial on 92 people with mild brain damage.In another trial on 27 elderly people with cognitive dysfunction, drinking green tea didn\u2019t improve their symptoms but reduced oxidative damage, possibly helping reduce their progression.Epigallocatechin gallate improved visual recognition memory, working memory, inhibitory control, and adaptive behavior in 2 clinical trials on over 100 people with Down\u2019s syndrome. It also improved cognitive function in mice with this condition.To sum up, limited evidence suggests that green tea may improve cognitive function in both healthy people and those with cognitive dysfunction. You may discuss with your doctor if it may be helpful in your case.