Caffeine

What Every College Student Should Know

By Kara Ten Kley, Registered Dietitian

For all of those late night study sessions everyone needs a little pick-me-up, but is reaching for a caffeinated beverage the right choice?

Caffeine affects the brain by blocking the chemical adenosine and releasing dopamine. This results in decreased drowsiness, constricted blood flow and an increased feeling of pleasure. The decreased blood flow also works as a pain reliever. It has been found that 65 mg of caffeine is as effective in relieving headaches as 648 mg of acetaminophen. Some aspirins contain caffeine, which boosts their pain relieving effects by 40%. Caffeine slows the rate of dopamine reuptake in the brain in the same way that amphetamines do. With both adenosine and dopamine being released in the body, individuals feel a sense of energy and well-being.

However, despite the positive effects of caffeine, consuming it exacts a price. Caffeine consumption has a number of side-effects which are directly proportional to the amount of caffeine consumed. The following table outlines the pros and cons of drinking caffeinated beverages.

Pros of Caffeine Intake Cons of Caffeine Intake
  • Increased sense of alertness
  • Positive mood change
  • Can increase athletic performance
  • Can alleviate headaches
  • May reduce risk of:
    • Diabetes
    • Parkinson's Disease
    • Gallstones
  • Sleep disruption
  • Increased heart rate
  • Increased blood pressure
  • Decreased blood flow to stomach
  • Can result in dizziness, irritability, gastrointestinal upset and restlessness
  • Can increase risk of osteoporosis in later age
  • Is addictive

How much caffeine are you drinking? American adults consume an average of 200 mg of caffeine daily. That amount is enough to make some individuals feel anxious or irritable. Two hundred mg is equivalent to two 8-ounce cups of coffee and between three to four 12-ounce cans of decaffeinated soda. The table below lists the caffeine content of common beverages.

12 oz Beverage Mg of Caffeine 8 oz Beverage Mg of Caffeine
Red Bull (8.2 oz) 80 Coffee, Drip 115 – 175
Jolt 71.2 Coffee, Brewed 80 – 135
Mountain Dew 55 Coffee, Espresso (2 oz) 100
Diet Coke 45.6 Coffee, Instant 65 – 100
Dr. Pepper 41 Tea, Iced 47
Pepsi-Cola 37.5 Tea, Brewed, Imported 60
Diet Pepsi 36 Tea, Brewed, Domestic 40
Coca-Cola Classic 34 Tea, Instant 30
Snapple Flavored Teas 31.5 Tea, Green 15
Nestle Sweet Iced Tea 26.5 Hot Cocoa 14
Barq's Root Beer 23 Coffee, Decaf, Brewed 3 – 4
Lipton Brisk, All Varieties 9 Cofee, Decaf, Instant 2 – 3
Sprite 0
7-up 0
SOURCES: National Soft Drink Association, US Food and Drug Administration, Bunker and McWilliams, Pepsi, Slim-Fast

Bibliography

Brain, Marshall (No Date) How Caffeine Works. October 20, 2006, from http://home.howstuffworks.com/caffeine3.htm

Leduc, Mark (2004) Is Coffee Good or Bad for your Health? October 20, 2006, from http://www.healingdaily.com/detoxification-diet/coffee.htm

Nutrition Action Health Letter (1996) Caffeine: The Inside School; the good, the bad, and the nyth. October 20, 2006, from http://www.cspinet.org/nah/caffeine/good_bad.htm