Caffeine is the most widely used drug in the world. In the United States alone, eight out of ten of us rev up our bodies each morning with a dose of caffeine, and of this group, half of us will tailor our high all day long—going back to the coffee or tea pot, or to the soda or snack machine—several times for a re-load.

Caffeine works by stimulating the adrenal glands of the body into a state of emergency—triggering many of the same mechanisms involved in the body’s well know fight or flight response. It takes coffee or tea about 15 to 30 minutes to have an effect on the brain, and about one hour to reach maximum blood levels. The half life of caffeine in the bloodstream is between 3—7 hours, depending upon a person’s age, activity, and individual chemistry.

What does this mean for our sleep at night? Insomnia experts recommend that anyone who suffers from the classic symptoms of insomnia—difficulty falling asleep, frequent awakenings during the night to use the restroom, or early morning arousals—assess their caffeine use carefully. According to a recent study performed at Stanford University Medical School, anyone who consumes more than 500 mg. of caffeine per day may have a dependency problem.

To give an idea of how easy it is to become dependent on caffeine, consider the following statistics. A 10 oz. cup of drip coffee contains roughly 250 mg. of caffeine. Percolated coffee tends to be milder in its caffeine dose—about 200 mg. Loose black tea, brewed 5 minutes, contains about 150 mg. of caffeine, while a 10 oz. cup of tea brewed from a tea bag contains only 50 mg. Green tea, frequently touted as an alternative to caffeine rich black teas, actually contains very nearly the same amount of caffeine as black teas.

Caffeine is not only found in coffee and teas. Most sodas contain significant amounts of caffeine, as does chocolate, cocoa, and some medications—including combinations of aspirins and cold medicines.

According to Norman Ford in The Sleep Rx, in doses higher than 500 mg. per day, caffeine can elevate blood pressure, cause nervous anxiety, can lead to frequent urination, and has been linked to a higher risk of fibrocystic breast disease, and of osteoperosis in women. It may also contribute to a biochemical deficiency of calcium and potassium, and of vitamin B1. A deficiency of B1 leads to coffee nerves, fatigue, anxiety, depression, and difficulty concentrating. Fatigue is often due to overstimulation of the adrenal glands. Caffeine may also have an adverse effect on heartbeat rate.

In another study conducted by the National Institute of Environmental Health Sciences, it was discovered that of 104 women trying to conceive, those drinking more than one cup of coffee per day were 50% less likely to become pregnant at any stage of their menstrual cycle than women who consumed less caffeine. After drinking 1 cup or more of coffee per day for 1 year, women in the study were found to be 5 times less likely to become pregnant. The statistics are shocking, and the message is clear. Caffeine, in high doses, can be toxic.

Peter Hauri, in his excellent book on insomnia No More Sleepless Nights, suggests that anyone with insomnia who is a regular user of caffeine take a week off—go cold turkey—and watch for changes in your sleep and energy patterns during the day. If you experience any of the immediate symptoms of withdrawal—headaches, fatigue, agitation, or irritation—know you have a dependency. After one week, however, you also will be able to notice the high of being caffeine-free. Better sleep at night, less anxiety and more energy during the day, and better health overall.

Caffeine can be a nice energy boost, but like all drugs it can be abused. In moderation—one to two “doses” per day, with little to none after noon—most of us can avoid its perils. But if you complain of difficulty sleeping at night, or if you are a woman trying to conceive, your love affair with caffeine should be re-evaluated.

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