Green tea caffeine does not make you jittery or nervous. If you're looking for a coffee or soda substitute with just the right amount of caffeine enough to keep you awake and energized without the nervousness, chronic muscle tension, irritability, headaches, depression, and insomnia, Japanese Green Tea is exactly what you've been looking for.

Japanese Green Tea offers the best of both worlds when it comes to caffeine -- just enough to provide a stimulating pick-me-up that banishes unwanted drowsiness, but not enough to trigger nervousness or sleepless nights.

Ever since eight-century Buddhist monks discovered that tea helped them remain awake during long meditation sessions, tea has been used to boost lagging energy, refresh the mind, and brighten up the mood.

Caffeine increases your heartbeat, improves your alertness, your reaction time gets faster and your general mood becomes more "upbeat".

But to get the benefits of caffeine, you only need to consume the recommended caffeine intake.

The recommended caffeine intake per day is 200 mg.

The average cup of green tea contains anywhere from 8 to 20 mg of caffeine, while black tea contains at least twice that amount -- 40 to 60 mg. Soda contains between 40 to 60 mg and a cup of drip coffee has a nerve-jangling 90 to 150 mg, more than half the amount of caffeine that some people should consume in a whole day.

Just 3 cups of coffee a day is enough to give you the problems like headaches, depression, insomnia, irritability and nervousness, if consumed on a daily basis for a long period of time.

It would take at least 4 cups of the strongest green tea to equal the caffeine content of the weakest drip coffee. Still, green tea does have a "brightening" effect.