Caffeine

Author: Betty Kovacs, MS, RD
Medical Editor: Melissa Conrad Stöppler, MD

What is caffeine?

There are few people who are not aware of the stimulating effect that caffeine provides. We have a choice and choose caffeinated beverages for a reason. Caffeine is considered the most commonly used psychoactive drug in the world. Approximately 90% of adults consume it on a daily basis, and research is being done on its health benefits and consequences.

We may love our caffeine, but what exactly is it? Caffeine is the common name for 1,3,7-trimethylxanthine. When purified, caffeine produces an intensely bitter white powder that provides a distinctive taste in soft drinks. The word "caffeine" came from the German word kaffee and the French word café, each meaning coffee. After ingesting caffeine, it is completely absorbed within 30 to 45 minutes, and its effects substantially diminish within about three hours. It is eventually excreted so there is no accumulation in the body. Caffeine has been shown to affect mood, stamina, the cerebral vascular system, and gastric and colonic activity. But caffeine may not be for everyone. This article will discuss the health benefits and consequences of caffeine.

What are the sources of caffeine?

Caffeine is naturally found in certain leaves, beans, and fruits of over 60 plants worldwide. Its bitterness acts as a deterrent to pests. The most common sources in our diet are coffee, tea leaves, cocoa beans, cola, and energy drinks. Caffeine can also be produced synthetically and added to food, beverages, supplements, and medications. Product labels are required to list caffeine in the ingredients but are not required to list the actual amounts of the substance.

The U.S. Food and Drug Administration (FDA) and the American Medical Association (AMA) classify a "moderate intake" of caffeine as "generally recognized as safe." This means that if you consume a moderate amount it is generally safe for the people on whom it has been studied. Most of these studies have been done on adults. Here is the definition of what is considered low, moderate, high, and heavy amounts of caffeine intake:

• a low to moderate intake is 130 mg-300 mg per day



• a moderate is 200 mg-300 mg per day



• high doses are above 400 mg per day



• heavy caffeine consumption is more than 6,000 mg/day.

It is estimated that the average daily caffeine consumption among Americans is about 280 mg/day, while 20%-30% consume more than 600 mg daily. The top three sources of caffeine in adults are coffee (70%), soda (16%), and tea (12%).

One mistake that people make is assuming that decaffeinated means that there is no caffeine in the food or beverage. Decaffeinating happens through a process. According to the site Coffeeresearch.org, decaffeinating coffee usually consists of soaking the beans in water to dissolve the caffeine, extracting the caffeine with a solvent or activated carbon, and then re-soaking the beans in the decaffeinated water to reabsorb the flavor compounds that were lost in the initial extract. A study published by the Journal of Analytical Toxicology found that nine out of 10 tested cups of decaf coffee from coffee from shops and restaurants contained 8.6 mg-13.9 mg of caffeine. It also found that decaffeinated espresso shots contained 3 mg-16 mg of caffeine per shot. Another study done by Consumer Reports tested 36 cups of small decaf coffees from six locations. They found that more than half had less than 5 mg of caffeine while the rest had a range from 20 mg-32 mg per cup. Depending on how much you consume in a day, you can end up consuming more caffeine from decaffeinated drinks than you would in one cup of coffee.

There is no way to know for sure exactly how much caffeine you consume so it's a good idea to put a limit on the total amount caffeinated and decaffeinated products that you consume. You can also choose products with lower caffeine contents. You won't find the content on the food labels, so refer to this chart. Make sure that you check the serving size on the can, bottle, or cup and do the math based on the serving size provided here:

Sources of caffeine	Caffeine content
Coffee
Plain, brewed 8 oz	135 mg (range 102-200)
Instant 8 oz	95 mg (range 27-173)
Espresso 1 oz	40 mg (range 30-90)
Plain, decaffeinated 8 oz	5 mg (range 3-12)
Tea
Tea, brewed	53 mg (range 40-120)
Green tea 8 oz	25-40 mg
Black tea 8 oz	40-70 mg
Soft drinks
Barq's Root Beer	22 mg
Coca-Cola Classic 12 oz	35 mg
Diet Coke 12 oz	47 mg
Dr. Pepper 12 oz	42 mg
Dr. Pepper, diet 12 oz	44 mg
Jolt Cola 12 oz	72 mg
Mountain Dew, regular or diet 12 oz	54 mg
Mountain Dew, MDX, regular or diet 12 oz	71 mg
Pepsi-Cola 12 oz	38 mg
Pepsi, diet 12 oz	36 mg
Sunkist Orange 12 oz	42 mg
Tab 12 oz	46.5 mg
Vault 12 oz	71 mg
Energy drink
Full Throttle 16 oz	144 mg
Monster Energy 16 oz	160 mg
Red Bull 8.5 oz	80 mg
Rip It 8 oz	100 mg
SoBe No Fear 8 oz	130 mg
Spike Shooter 8.4 oz	300 mg
Chocolate, candies, other
Candy, milk chocolate 1 bar (1.5 oz)	9 mg
Candy, sweet chocolate 1 bar (1.45 oz)	27 mg
Cocoa mix, powder 3 tsp	5 mg
Hershey's Special Dark Chocolate Bar 1.45 oz	31 mg
Hot cocoa 8 oz	9 mg (range 3-13 mg)
Jolt caffeinated gum 1 stick	33 mg
Puddings, chocolate, ready to eat 4 oz	9 mg
Frozen desserts
Ben & Jerry's Coffee Heath Bar Crunch 8 oz	84 mg
Ben & Jerry's Coffee Flavored ice cream 8 oz	68 mg
Häagen-Dazs Coffee ice cream 8 oz	58 mg
Häagen-Dazs Coffee frozen yogurt 8 oz	58 mg
Medicine: over the counter
Excedrin Extra Strength 1 tablet	65 mg
Bayer Select Maximum Strength	65.4 mg
Midol Menstrual Maximum Strength	60 mg
NoDoz Maximum Strength 1 tablet	200 mg
Pain Reliever Tablets	65 mg
Vivarin 1 tablet	200 mg

Source: MedicineNet.com
http://www.medicinenet.com/caffeine/article.htm