Health Effects of Caffeine

When patients talk to Nancy Buchholz, APNP, at ThedaCare Physicians-Black Creek about their problems with insomnia, high blood pressure, or anxiety, she makes it a point to ask them about their use of caffeine. “It’s a drug, a legal drug, but many people still need help to assess their use and dependence on caffeine. It has far-reaching effects on a person’s overall health,” said Buchholz.

Caffeine works by stimulating the central nervous system, heart, muscles, and the centers that control blood pressure. About 80 percent of the adult population in the US consumes caffeine, and about 20 percent consume over 350 mg daily, a level sufficient to cause physical dependency.

Caffeine can be beneficial when it is used in moderation to treat or improve:

  • Migraine or tension headaches
  • Mental alertness

However, caffeine can cause serious health problems when it causes or aggravates:

  • Anxiety disorders
  • Irritable bowel syndrome
  • Diarrhea
  • High blood pressure
  • Heart conditions
  • Glaucoma

When caffeine appears to be the culprit, Buchholz often recommends that her patients cut back on their use of caffeine, not eliminate it entirely from their diet. “Everything in moderation,” she says, noting that coffee drinkers might brew a pot of coffee with half regular coffee and half decaf. Avoid the empty calories and caffeine in soda and opt for chocolate milk instead. “The protein in the milk will boost your energy level over the long term, not just a quick jolt and a quicker let-down.”

And what about those highly caffeinated energy drinks? Don’t use them, says Buchholz. She’s seen the cycle of dependence on energy drinks quickly spiral out of control, especially for shift workers. “The combination of sugar and caffeine causes such a burst of alertness that the withdrawal becomes quite severe. Then the person needs more caffeine and sugar to revive his or her energy level. It’s a vicious cycle that is difficult to break.”

Kids and caffeine don’t mix. A child (age 1-5) consuming one can of caffeinated soda receives a caffeine equivalent of 4 cups of coffee for an adult Caffeine is readily absorbed by the body, with blood levels peaking about 30 minutes after ingestion. The clearance rate from the blood varies from several hours in an adult to several days in a newborn.

If you decide to cut back or eliminate your use of caffeine, expect a short period of withdrawal (three to five days) which may involve irritability, headaches, sleepiness and constipation. Then opt for some healthier alternatives for boosting your energy:

  • Drink water – Picture a wilting flower. Chances are, all you need is water, or rehydration, to regain your alertness and energy.
  • Perk up with protein – a handful of nuts or seeds instead of an afternoon coffee break will supply and maintain energy levels
  • Get enough good quality, consistent sleep
  • Exercise to boost your endorphins, your body’s natural energy boosters Take a short walk around the plant or office on your break. Schedule exercise throughout the week.

Caffeine occurs naturally in plants, in varying amounts. The coffee bean and the tea bush are the most familiar sources. The same amount of coffee or tea, prepared differently, varies widely in caffeine content (Instant coffee has 65 mg versus percolated coffee that has 110 mg/cup.):

  • Brewed coffee, 8 oz. - 95-200 mg
  • Espresso, 1 oz. - 47-75 mg
  • Black tea, 8 oz. - 14-70 mg
  • Green Tea 8 oz. - 24-45 mg
  • Coca-Cola, 12 oz. - 23-35 mg
  • Mountain Dew, 12 oz. - 42-55 mg
  • 5-Hour Energy Shot, 2 oz. - 200-207 mg
  • Excedrin Extra Strength, 1 tablet - 65 mg

Find a care provider who can help you wake up to the effects of your everyday choices. Nancy Buchholz, APNP, is accepting new patients at ThedaCare Physicians-Black Creek at (920) 984-3361. Or call ThedaCare On Call at (920) 830-6877 or go to and click on “Find a Doctor.”