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Caffeine myths and facts

Is caffeine bad for you, or can it be good for you?

Caffeine doesn't just come from coffee, tea and some fizzy drinks, you even get caffeine from chocolate and some medicines.

We help you sort out the caffeine myths from the facts.

Caffeine is addictive

This one has some truth to it, depending on what you mean by "addictive." Caffeine is a stimulant to the central nervous system, and regular use of caffeine does cause mild physical dependence. But caffeine doesn't threaten your physical, social, or economic health the way addictive drugs do.

If you stop taking caffeine abruptly, you may have symptoms for a day or more, especially if you consume two or more cups of coffee a day. Symptoms of withdrawal from caffeine include:

Although caffeine withdrawal can make you feel bad for a few days, it does not cause the severity of withdrawal or harmful drug-seeking behaviours as drugs or alcohol. For this reason, most experts don't consider caffeine dependence a true addiction.

Caffeine is likely to cause insomnia

Your body quickly absorbs caffeine. But it also gets rid of it quickly. Processed mainly through the liver, caffeine has a relatively short half-life. This means it takes about four to five hours, on average, to eliminate half of it from your body. After eight to 10 hours, 75% of the caffeine is gone. For most people, a cup of coffee or two in the morning won't interfere with sleep at night.

Consuming caffeine later in the day, however, can interfere with sleep. If you're like most people, your sleep won't be affected if you don't have caffeine within six hours before going to bed. Your sensitivity may vary, though, depending on your metabolism and the amount of caffeine you regularly consume. People who are more sensitive may not only experience insomnia but also have caffeine side effects of nervousness and gastrointestinal upset.

Caffeine increases risk of conditions such as osteoporosis, heart disease and cancer

Moderate amounts of caffeine -- about 300 milligrams, or three cups of coffee -- apparently cause no harm in most healthy adults. Some people are more vulnerable to its effects, however. That includes people such as those who have high blood pressure or are older. Here are the facts:

Osteoporosis and caffeine. At high levels (more than 744 milligrams/day), caffeine may increase calcium and magnesium loss in urine. But recent studies suggest it does not increase your risk of bone loss, especially if you get enough calcium. You can offset the calcium lost from drinking one cup of coffee by adding just two tablespoons of milk.

However, research does show some links between caffeine and hip fracture risk in older adults. Older adults may be more sensitive to the effects of caffeine on calcium metabolism. If you're an older woman, discuss with your doctor whether you should limit your daily caffeine intake to 300 milligrams or less.

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