With caffeine our brain becomes more alert. Caffeine increases the levels of dopamine in our brain, which improves our “good” feeling and improves our mood. All this is dopamine effect and because that caffeine has addictive properties.
Many beverages such as coffee, tea and other drinks contain caffeine in moderate or high proportions. It is recommended to check out Caffeine Content to find more details about caffeine content in other drinks and foods.
People are now much more concerned about the health effects of caffeine, because in recent years has been reported some cases of caffeine toxicity. This includes overdosing with caffeinated energy drinks and caffeinated diet supplements.
Green tea comes from the leaves of the Camellia sinesis plant (the tea tree plant). This plant naturally contains caffeine. So, green tea does contain caffeine, but caffeine from natural plants has proven safe over thousands of years of human use. If we compared the caffeine content of green tea with other sources of caffeine, we can conclude that green tea include very low caffeine content. There are some evidences that caffeine functions in a positive synergistic way can enhance the health benefits of green tea.
What is considered a normal amount of caffeine depends on an individual’s sensitivity. Generally, the US Food and Drug Administration (FDA) carefully reviewed and deemed caffeine as safe and also effective. Caffeine in green teas is considered as safe, because green tea contain natural caffeine that is considered Generally Recognized As Safe (GRAS) by the FDA.
Most experts are of the opinion that caffeine contributes to dehydration and for a long time caffeine has been considered as a diuretic. Other studies have found that caffeine has mild diuretic effects similar to water. If we consume moderate amounts of caffeine, the body retains some of the fluids.
Even though green tea has relatively high caffeine content, the catechin doesn't allow it to dehydrate the body. So it is even more potent than water.
Green tea also has other nutrients in it that have been linked with significant health benefits. It contains L-theanine that increases some of caffeine’s stimulant effects. L- theanine is one of few amino acids that has been found to reduce anxiety, lower blood pressure, increase alpha brain wave activity, improve learning ability, boost immune systems etc.
Caffeine content of green tea can have variations from 7 milligrams to 75 milligrams per cup. Green tea contains approximately 15-40mg of caffeine in an average 8 ounce cup. Generally caffeine content depends on the quality of the tea and how it’s brewed.
Compared caffeine content in beverages (these are approximate figures, depending on preparation methods):
|Beverages (average cup, 8 oz)||Caffeine content (milligrams)|
|Green tea||15 - 40|
|Regular coffee||100 - 200|
|Instant coffee||50 - 100|
|Espresso||400 (100 mg for two ounces)|
|Black tea||40 -80|
|Cola soft drink||35|
|Diet cola soft drink||47|
|Other soft drinks||0 - 80|
|Caffeine tablets||100 - 200|
It has been estimated that about 75 percent of Americans consume coffee daily. It’s more than a 450,000,000 cups a day. An average cup of coffee contains the most caffeine; the same cup of green tea provides 1/5 to 1/2 as much.
Because green tea contains less caffeine than other beverages it can be drank in the evening without fear of insomnia.
So, green tea remains the best choice out of all caffeine containing beverages.
It is generally agreed that consuming 130 - 300 mg of caffeine per day is safe. However caffeine may not be for everyone. We can always drink decaffeinate green tea (with special preparation method) or use caffeine free brands of this tea.
Read more about green tea caffeine content at Caffeine in Green Tea
Note: All figures are approximate; this site does not provide medical advice, diagnosis or treatment.