For most of us, caffeine is part of our daily lives, whether it’s a cup of java to get us going in the morning or a diet soda on our afternoon break.
“Caffeine takes only 15 to 20 minutes to get into the bloodstream, yet we feel its effects for up to 10 hours,” says Beth Czerwony, MS, RD, LD, a registered dietitian at Cleveland Clinic.
Sometimes those effects are more than just a pick-me-up. Caffeine can cause headaches, irritability, sleeping problems, heart palpitations, gastrointestinal distress and dehydration. If caffeine gives you the jitters or you find you’re becoming too dependent on it, consider cutting back, says Ms. Czerwony.
Caffeine: Are there limits?
Most healthcare experts advise against caffeine consumption for women who are pregnant and children under age 12. But what about other people?
“Caffeine has possible beneficial effects on inflammation and endothelial function [important for heart health] and risk for type 2 diabetes,” says Raul Seballos, MD, Vice Chair of Preventive Medicine at Cleveland Clinic.
A large study reported in the June 2008 Annals of Internal Medicine found no link between regular coffee consumption and increased death rates from cardiovascular disease, cancer and all causes.
“No significant negative or positive effects were seen in men who drank less than one cup of coffee per month up to more than six cups of coffee per day,” says Dr. Seballos. ”And women who drank four to five cups of coffee per day had the greatest benefit in reducing mortality from all causes.”
All things in moderation
Dr. Seballos nevertheless preaches moderation in caffeine consumption — just as he does with alcohol. He advises both the men and women he sees to have no more than two to three cups of coffee per day.
To determine how much caffeine is in your favorite beverage or treat, start by reading labels. Below are six popular sources of caffeine. Caffeine content may vary according to many factors, and different amounts are reported, so the numbers below are estimates.
1. Coffee. The caffeine in an 8-ounce mug of coffee varies according to whether it’s brewed, instant or decaf. “Even decaf delivers a minor jolt of caffeine,” says Ms. Czerwony:
- Brewed coffee — about 85 (range: 65 to 120) mg of caffeine
- Instant coffee — about 75 (range: 60 to 85) mg of caffeine
- Decaf — about 2 to 4 mg of caffeine (decaffeinated coffee must be at least 97.5% caffeine-free)
2. Tea. A typical 8-ounce cup of tea contains less caffeine than the same amount of coffee. How much depends on how long you steep tea and whether you prefer black, green or white:
- Black tea — about 40 (range: 20 to 90) mg of caffeine
- Black tea decaf — about 2 to 10 mg of caffeine
- Green tea — about 20 mg of caffeine
- White tea — about 15 mg of caffeine
- Herb tea contains 0 caffeine! (Most, but not all, herb teas are caffeine-free and labeled as such on the box)
Generally, the less time you brew tea, the less caffeine it contains. “To reduce caffeine levels further, steep tea for five minutes, then throw out the liquid and re-steep the bag in fresh water,” advises Ms. Czerwony. “This should remove almost all caffeine.”
3. Soft drinks. An increasingly common source of caffeine, especially for teens, 12-ounce sodas contain lots of calories and varying amounts of caffeine, from 54 mg in Mountain Dew to 34 mg in Coke to 0 mg in 7-Up. Even “un-colas” such as root beer and cream soda contain caffeine.
4. Energy drinks. Energy drinks, loaded with caffeine and sugar, are popular among college students, anyone driving long distances, and athletes wishing to enhance performance, says Ms. Czerwony. The caffeine content ranges from about 80 mg in an 8-ounce can of Red Bull to about 160 mg in a 16-ounce Rockstar.
5. Chocolate. Dark chocolate may be good for your heart, but it can get it racing too — 1 ounce contains 20 mg of caffeine, while the same amount of milk chocolate contains about 6 mg of caffeine. And parents, an 8-ounce carton of chocolate milk guarantees that your kids will get calcium — but they’ll also get sugar and caffeine (about 4 mg).
6. Coffee-flavored desserts. If you’re going to indulge in 8 ounces of Ben & Jerry’s Coffee Fudge Frozen Yogurt, do it early in the day. With 85 mg of caffeine, it’s like drinking coffee.