Effects On Alertness Article

Caffiene in Tea

Effects of Caffeine on Alertness

Caffeine, which occurs naturally in tea and coffee, has been extensively researched. Numerous studies have looked at the effects of caffeine on mental alertness and physical performance and have shown that caffeine can have beneficial effects. Ever since 8th century Buddhist monks discovered that it could help them stay awake during marathon meditation sessions, tea has been used to increase energy, brighten the mood and refresh the mind. The invigorating effects of tea are due to caffeine, a central nervous system stimulant that fights sleepiness, speeds up the heart rate, increases alertness, improves athletic endurance, assists in weight loss by speeding up the metabolism and may even heighten intellectual activity.

Studies have shown: sustained attention during after-lunch dip; improved alertness and performance on a variety of tasks at night; improved attention, psychomotor, memory test results after strenuous exercise; reversed changes caused by sleep-deprivation such as decreased in vigor, fatigue and confusion; and improved success in overcoming sleeplessness. Caffeine has also been shown to significantly increase wakefulness, vigor, energy, feeling "full of go" and feeling efficient. Increases in cognitive performance and in alertness, energy, and well being have been shown at levels of caffeine equivalent to those found in one cup of tea.

Caffeine affects the central nervous system, activating blood circulation, increasing mental alertness, counteracting sleepiness and helping you bounce back from fatigue. It improves athletic endurance by stimulating the breakdown and use of fat as an energy source, so the body doesn't deplete its glycogen stores. A natural diuretic, caffeine increases urination, which can help detoxify the body and lower the blood pressure. It's long been used as a remedy for hangovers because it blocks absorption of alcohol and helps the body dispose of it at a faster rate.

Of course, the downside of caffeine is that too much can make you nervous, irritable, and unable to fall asleep at night. It can also reduce fine motor coordination and trigger headaches and dizziness. Most healthy adults can handle 200-250 mg. per day without adverse effects, but some find that even a small dose makes them jittery.

However, green tea may offer the best of both worlds -- just enough to brighten the mood, but not enough to trigger sleepless nights. The average cup of green tea contains about 20 mg of caffeine, while black tea has about 40 mg, and drip coffee packs a nerve-jangling punch of 90-150 mg. Although some who are sensitive to caffeine may find that drinking green tea (especially in large amounts) keeps them awake at night, most people don't have this problem. That may be because green tea also contains theanine, an amino acid that functions as a natural tranquilizer.

Theanine

Tea comes from Camellia sinensis, which is the only plant that makes Theanine. Unique to tea, Theanine is a major amino acid in black, green, and oolong tea. Because Theanine seems to help the mind stop racing it also seems to help promote a more restful, sound sleep because sleep is also not interrupted by random thoughts. The science of Theanine is just developing and it is not known if the effect of Theanine is cumulative, but it does appear that the rejuvenating effects of tea on mood, cognitive function and psychomotor performance, that cannot be solely explained by the caffeine in tea, may be in part be due to Theanine.

With availability of decaffeinated teas, the negative effects of caffeine can be mitigated. So if you are one who must limit your intake of caffeine it is still possible to get the many health benefits of drinking tea by using it in its decaffeinated form.