Caffeine – The Good, The Bad, The Difference

I remember being told when I was young that drinking coffee would stunt my growth.  What was this “old wives tale” trying to protect me from?  The only thing I can think of is caffeine.

Caffeine naturally occurs in coffee beans and tea leaves so it has to be good, right?  Buddhist monks took tea around the world partly because it helped them stay up during long meditations.  I often hear people say they experience a “caffeine crash” when they drink coffee but not with tea.  So what is the difference between the caffeine in tea and coffee?

In 2006, I posed this question to David Liao, Director of the Taiwan Tea Research Institute.  He explained the molecular bonds holding the caffeine together are different in tea and coffee.  Tea undergoes less processing.  Therefore, the bonds in tea are more rigid.  This stability causes two different reactions.  First, a notable amount of the caffeine in tea passing through the body undigested.  Secondly, the caffeine that remains in the digestive system is absorbed at a slower rate compared to the body’s absorption of caffeine in coffee.

Generally speaking, there is less caffeine in a cup of tea vs a cup of coffee.  Black tea has one-third to one-half the caffeine in an equivalent portion of coffee.  Rule of thumb is lighter teas have less caffeine than darker teas.  White tea has the least amount of caffeine.  Black tea has more.  Caffeine content in a cup of tea is also dependent upon two other factors; steeping time and water temperature.   The longer the leaves steep, the more caffeine ends up in the cup.  Heat leaches caffeine out of the leaves.  Therefore, the higher the water temperature, the more caffeine will wind up in the drink.

Here is a quick reference chart.

Caffeine per 6 oz. serving

Espresso (2 oz)  100 mg

Drip Coffee  60-70 mg

Black Tea  30-40 mg

Oolong Tea  12-55 mg

Mountain Dew  27 mg

Coke  17 mg

Dark Chocolate (1 oz) 17 mg

Green Tea 8-16 mg

Milk Chocolate (1 oz)  6 mg

Information gathered from various sources including National Soft Drink Association and The Hershey Company.

Caffeine and other stimulants are available in so many different forms.  9 out of 10 adults in the US drink some form of caffeinated beverage.  Funny thing is parents tell me they don’t allow their children to drink tea because it contains caffeine but the kids drink colas and hot chocolate.  What’s worse, the caffeine or the sugar?