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The Power of Caffeine

The power of caffeineWe all know caffeine has the power to perk us up, keep us focused and possibly help ward off certain diseases. But the stimulant, enjoyed by more than 80% of Americans, has other lesser-known side effects.

"The good news is we aren't seeing any long-term negative health consequences linked to moderate caffeine consumption," says Sarah Stolte, MD, internal medicine physician at The University of Kansas Health System.

In fact, caffeine may be beneficial if consumed in moderate amounts – about 400mg a day for healthy adults, and less for pregnant or nursing women, according to Dr. Stolte. That's roughly equivalent to 3 cups of coffee and 3 cans of soda per day. When consumed in healthy doses, some studies suggest that caffeine may reduce your risk for a number of conditions, including:

But caffeine lovers are likely most fond of the quick energy boost it provides. The effects of caffeine last 4-6 hours for most people, but there are some exceptions.

"Medications, like oral contraceptive pills and alcohol, metabolize through the same liver pathway and can increase the length of effect for caffeine," Dr. Stolte says. "Women on birth control may see 6-8 hours of benefit. Tobacco and marijuana accelerate caffeine metabolism, and shorten the benefit."

How much caffeine are you getting?

  • An 8-ounce cup of coffee: 95mg on average
  • A 12-ounce can of Coke: 30mg
  • Hershey's chocolate bar: 9mg
  • An 8-ounce cup of tea: 40-100mg
  • An 8-ounce cup of decaf coffee: 3-18mg
  • Two tablets of Excedrin® Migraine: 130mg

See more caffeine totals.

Risks and side effects

While moderate amounts of caffeine can be beneficial, some people may not realize how much caffeine they're consuming or when they're consuming it. For example, some designer coffees can pack as much as 475mg in a large cup. Caffeine can also sneak into certain medications, coffee-flavored foods (like yogurt), anything that contains chocolate and even some decaf coffees.

Even if your caffeine intake is within the normal range, Dr. Stolte says you still may experience heart palpitations, restlessness or irritability – just some of the negative side effects that may become more pronounced the more caffeine you drink.

"Caffeine also has a diuretic effect," Dr. Stolte says, "which can cause dehydration and electrolyte abnormalities. With pregnant women, we know caffeine consumption in the first trimester can increase the risk of miscarriage. In men, it can cause poor sperm quality."

In fact, Dr. Stolte says research has linked normal caffeine consumption to fertility problems in men and women. Other common negative side effects can include:

  • Confusion
  • Food avoidance/anorexia
  • Headaches
  • Heartburn
  • Muscle aches
  • Upset stomach
  • Increased blood pressure
  • Jitters and muscle twitches
  • Osteoporosis

Health system gets its own blend

The University of Kansas Health System teamed up with The Roasterie to create a signature coffee called the 3901 Blend. The unique brew is a rich, full-bodied blend with notes of candied cherry, peanuts and Baker's Chocolate. It's available in the lobby of the Center for Advanced Heart Care, the main cafeteria hospital or the Westwood Campus Atrium.

Withdrawal symptoms

Because of its negative side effects, Dr. Stolte says people suffering from uncontrolled hypertension or anxiety, unstable heart arrhythmias and insomnia should avoid caffeine.

"Some drugs and medications are unsafe to stop cold turkey," she says. "Caffeine is not one of them. You'll have more headaches, more constipation and more fatigue, but quitting abruptly isn't overly harmful, just more symptomatic."

Most people who eliminate caffeine may experience anxiety, irritability, drowsiness, constipation, lack of concentration, rapid or irregular heartbeat or trouble breathing 12-24 hours after their last dose of caffeine. A more comfortable way to cut back is to taper off consumption or switch to decaf, which takes your caffeine intake down from an average of 100mg to about 15mgs.

Or, if you are looking for alternatives to caffeine that will still give you a jolt of energy or a boost of concentration, Dr. Stolte recommends 10 minutes of activity that increases your heart rate.

"A quick walk can be as stimulating as caffeine without any of the side effects," she says.

A personal choice

An early morning cup of Joe is a must-have for many. And if you aren't experiencing any negative side effects, there's no reason why you should have to give up your a.m. ritual. Dr. Stolte says it's up to each person to gauge how their body responds to caffeine and decide for themselves whether to make it part of their daily routine.

"Understanding how much caffeine you consume as well as the good and not-so-good effects will help you make a wise choice," she says.