An ingredient found in tea, L-theanine is the key reason behind tea’s ability to smooth out and calm the caffeine’s speedy, jolting punch of energy without reducing its accompanying mind-energizing, focus-building, and fat-burning features. It relaxes the body and calms the mind without causing drowsiness – a feature that has been found to improve sleep quality in volunteers during a study performed in Japan.
The subjects were given 200 mg of theanine daily and wore devices around their wrists that recorded sleep patterns. The L-theanine didn’t cause the subjects to sleep longer, but it did cause them to sleep better. Recovery from exhaustion, sleep quality, and refreshed feelings were all enhanced – making the subjects feel like they had slept longer than they actually had.
Another benefit of L-theanine is that it leaves people in a better mood – improving the volume of amino acids, elevating seratonin and suppressing glucocorticoids – stress hormones that can play a role in depression as well as negatively affect memory and learning.