Around 90 percent of Americans consume caffeine every single day in one form or another. More than half of all American adults consume more than 300 milligrams (mg) of caffeine every day, making it America’s most popular drug by far.
Here are the most common sources of caffeine for Americans:
- Typical drip-brewed coffee contains about 100 mg per 8-ounce cup.
- Typical brewed black tea contains 50 mg per 8-ounce cup.
- Typical caffeinated sodas (Coke, Pepsi, Mountain Dew, etc.) contain 40–50 mg per 12-ounce can.
- Super-caffeinated colas like Jolt contain 70 mg per 12-ounce can.
- Typical chocolate milk contains 6 mg per ounce.
- Maximum Strength Anacin contains 32 mg per tablet. NoDoz and Vivarin each contain 200 mg per tablet. Extra Strength Excedrin contains 65 mg per tablet.
- Energy drinks like Red Bull (8.3 oz-sized can) contain about 80 mg per can.
By looking at these numbers and by knowing how widespread coffee, chocolate, tea, cola and energy drinks are in our society, you can see why half of all American adults consume more than 300 mg of caffeine per day. Two mugs of coffee or a mug of coffee and a couple of Cokes during the day are all you need to get there.
Caffeine is a natural component of chocolate, coffee and tea, and is used as an added energy boost in most colas and energy drinks. It’s also found in diet pills and some over-the-counter pain relievers and medicines.
In its natural form, caffeine tastes very bitter, but most caffeinated drinks have gone through enough processing to camouflage the bitter taste. Most teens get the majority of their caffeine intake through soft drinks, which can also have added sugar and artificial flavors.
Caffeine has long been on the list of don’ts for people hoping to lead a healthy lifestyle. Doctors pointed to caffeine’s negative effects on the nervous system and how it can increase anxiety, stress and food cravings, in addition to inhibiting sleep. Recent studies, however, have shown that coffee and caffeine may actually have some significant medical benefits.
Coffee originated in Africa around 575 A.D., where beans were used as money and consumed as food. Records show that 11th century Arabs drank coffee regularly. Spanish conquistadors first exploring what is now Mexico, were served coffee by Montezuma, the mighty Aztec ruler, in 1519.
There have been more than 19,000 studies on caffeine and coffee in the past 30 years in an attempt to determine its exact effects on the human body. One of the most thorough and exhaustive studies was done by Harvard University, in which they examined 126,000 people over an 18-year period. The findings indicate that people who drink one to three cups of coffee a day are up to 9 percent less likely to contract diabetes. What’s interesting is what happened to those who drank six or more cups of coffee per day — men slashed their chances of contracting diabetes by 54 percent, and women by 30 percent!
Other studies have shown similar results in many facets of human health:
- Regular coffee drinkers are 80 percent less likely to develop Parkinson’s disease.
- Two cups a day gives you 20 percent less risk of colon cancer.
- Two cups a day causes an 80 percent drop in cirrhosis.
- Two cups a day prevents gallstone development by 50 percent.
- It has also shown to be beneficial in asthma, stopping headaches, boosting mood and even preventing cavities.
Some of these findings may have something to do with other healthful properties of the coffee bean, but most can be directly linked to caffeine. Researchers are even developing drugs for Parkinson’s disease containing caffeine derivatives.
In its natural form, caffeine tastes very bitter, but most caffeinated drinks have gone through enough processing to camouflage the bitter taste. Caffeine moves through the body within a few hours after it is consumed. It is not stored in the body, but you may feel its effects for up to 6 hours if you’re sensitive to it.
Long-term effects of a toxic nature do not appear evident when regular caffeine use is below about 650 mg a day — equivalent to about eight or nine average cups of coffee. Above this level, users may suffer from chronic insomnia, persistent anxiety and depression, and stomach ulcers. Caffeine use appears to be associated with irregular heartbeat and may raise cholesterol levels, but there is no firm evidence that caffeine causes heart disease.
Regular use of upwards of 350 mg of caffeine a day can cause physical dependence on the drug. This means that interruption of the regular use produces a characteristic withdrawal syndrome, the most conspicuous feature of which is an often severe headache that can be relieved by taking caffeine. Absence of caffeine also makes regular users feel irritable and tired. Relief from these withdrawal effects is often given as a reason for using caffeine.
If you have normal blood pressure, caffeine can increase it noticeably, but the increase is temporary and only lasts a short time. The increase generally includes the systolic and diastolic pressure readings, increasing each by approximately 4 to 13 mm Hg, or millimeters of mercury, according to the Mayo Clinic website. That means if you have a normal blood pressure reading of 120 mm for your systolic pressure and 80 mm for your diastolic pressure, caffeine can increase it up to about 133 over 93.
No one is sure why caffeine can increase blood pressure, although the Mayo Clinic site reports a few theories. One is that caffeine may cause your arteries to constrict by blocking a hormone that usually keeps them wider. Another is that caffeine may boost your adrenal glands’ release of more adrenaline, with the greater amount of adrenaline leading to the increase. In either case, the increase is always temporary rather than resulting in long-term increase in pressure.
If you cut down on your caffeine intake suddenly, you may experience headaches, irritability, tiredness, depression, nausea, vomiting and stiff or painful muscles. These symptoms generally appear 12 to 24 hours after you decrease or abstain from caffeine. Symptoms of caffeine withdrawal are usually mild and typically go away after a few days.
One thing is clear — despite the recent findings, most doctors still recommend moderation in regard to caffeine intake. While these recent studies give hope to those who are hooked on their morning cup, there is still a long way to go to determine the long-term effects of caffeine use.
Remember, I’m not a doctor. I just sound like one. Take good care of yourself and live the best life possible!
The information included in this column is for educational purposes only. It is not intended nor implied to be a substitute for professional medical advice. The reader should always consult his or her healthcare provider to determine the appropriateness of the information for their own situation or if they have any questions regarding a medical condition or treatment plan.
Glenn Ellis is a health advocacy communications specialist. He is the author of “Which Doctor?” and is a health columnist and radio commentator who lectures, and an active media contributor nationally and internationally on health related topics. His second book, “Information is the Best Medicine,” was released in January 2012. For more good health information, visit www.glennellis.com.