Many of you have asked for a discussion about the effects of caffeine.

Apparently, many Calvin students stop at the Fish House for that early morning cup of coffee to foster attention in 8 AM classes. Legend has it that Calvin engineering students consume vast quantities of Mountain Dew during all-night sessions in the engineering labs. Traveling Calvin students have been seen refueling their car at the gasoline pump and stocking up on No-Doz at the check-out counter.

Already you should be a little skeptical. I love my daily cup of coffee, as do a majority of Americans. On any given day, 85% of Americans use a caffeine product. The average daily consumption of caffeine in the U.S. is about 200 mg, or roughly 2 cups of coffee. This is three times higher than the world average (but half of the caffeine consumption of heavy tea-drinking countries such as England and Sweden ). So is any of the research related to caffeine completely without bias?

The questions about caffeine have brewed for years. J.S. Bach composed a cantata about the controversy surrounding his favorite stimulant. Just before he died, the French writer Balzac resorted to eating ground coffee beans to support his writing habits. This confirmed the suspicions of his contemporaries that he was a drug addict. Some historians claim that caffeine use in the western world is associated with the beginnings of the Industrial Revolution. Apparently the first accurate time pieces appeared with the infusion of caffeine into our beverages. Some propose that caffeine fueled modern man's increased productivity. A recent article in a respected medical journal claimed rubbing caffeine on your skin might prevent skin cancer. Another article claimed that caffeine consumption is essential to the information economy, as it provides specific cognitive benefits that allow people to perform computer work better for prolonged periods of time…..

Caffeine
Caffeine is a natural substance that can be extracted from plants. Natural sources of caffeine include coffee beans, tea leaves, and cocoa beans. It can also be produced synthetically.

Caffeine belongs to a group of stimulants called xanthines. It is considered a drug and begins to affect your body very quickly after consumption. It reaches peak level in your blood within 30 -60 minutes. The half-life of caffeine is about 3-5 hours, which means that in 5 hours your body has eliminated about half of the drug. The remaining caffeine can stay in your body for 8-14 hours. Caffeine stimulates the central nervous system and prompts the adrenal glands to release adrenaline, one of two hormones released in response to stress. (For information about stress, see last month's health news: Stress).

For many years, researchers have attempted to establish a relationship between caffeine consumption and the risk of diseases including osteoporosis, birth defects, miscarriages, infertility, breast disease, heart disease, ulcers, high blood pressure, cancers, and premenstrual syndrome (PMS). The authors of the epic 25 year Nurses Health Study failed to find any evidence to support the link between moderate coffee consumption (2-3 cups) and heart disease, cancer or any other serious consequence. According to the February issue of the Harvard Health Letter , moderate consumption may actually be related to a lower risk of Type 2 Diabetes, Parkinson's disease, and colon cancer. Researchers continue to evaluate the potential benefits of antioxidants in caffeinated beverages.

The caffeine levels in common drinks vary widely. An average cup of coffee has about 100 mg, and tea about 50mg. A 12 ounce can of Coke or Pepsi has about 36mg, while the same amount of Pepsi-One or Mountain Dew has 54 mg. Vivarin and No-Doz have about 200 mg per tablet, while Extra-Strength Excedrin has 130 mg in 2 tablets.

For a list of caffeine levels in common products, consult: http://www.mayoclinic.com/health/caffeine/AN01211

Positive Effects:
Caffeine has moderate benefit in promoting alertness and concentration. It can have a positive effect on your reaction times, mood and mental performance. It can help with the pain of migraine headaches. It works best when you take it on an intermittent basis. A reasonable dose is between 50-200mg.

Negative effects:
Caffeine can disrupt sleep. As many of you may know from personal experience, late night caffeine can make it difficult to fall asleep. This reduces total sleep time. In addition, it can interfere with the quality of sleep, limiting deep sleep.

Other common side effects at high doses include diarrhea, sweating, nausea, increased heart rate, increased breathing rate, muscle tremors, and heartburn.

Caffeine may amplify the effects of stress, exaggerating the stress response both in terms of the elevation in stress hormones, and in a person's response to stress.

Withdrawal symptoms can occur when stopping caffeine after a period of regular use. Headaches, sleepiness, low energy levels, and bad moods may persist for several days.

Summary:

• Limit caffeine consumption to no more than 300-400 mg per day. This is equivalent to about 3-4 cups (8-oz) of coffee.
• Women who are pregnant or nursing should consume even less, perhaps 2 cups maximum or avoid it altogether.
• People with high blood pressure or other heart problems should avoid high levels of caffeine.
• Avoid caffeine in the late afternoon or evening, especially if you struggle with insomnia.
• If you are suffering from the effects of stress in your life, or just generally feel “stressed out”, try eliminating caffeine and see if you feel better.

Finally, view with suspicion any advice to increase consumption to gain health advantage. Chances are, there may be a researcher or two who enjoys his espresso.

Time for my coffee break……..