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 for 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.

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 five to seven hours, on average, to eliminate half of it from your body.

Any regular coffee drinker may tell you that caffeine improves alertness, concentration, energy, clear-headedness, and feelings of sociability.

research suggests that people only think caffeine helps them sober up. For example, people who drink caffeine along with alcohol think they're OK behind the wheel. But the truth is reaction time and judgment are still impaired. College kids who drink both alcohol and caffeine are actually more likely to have car accidents.

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.

...

Cancer and caffeine. Reviews of 13 studies involving 20,000 people revealed no relationship between cancer and caffeine. In fact, caffeine may even have a protective effect against certain cancers.

A slight, temporary rise in heart rate and blood pressure is common in those who are sensitive to caffeine. But several large studies do not link caffeine to higher cholesterol, irregular heartbeats, or an increased risk of cardiovascular disease.

most popular non addicting drug. its the stimulant in coffee, tea, chocolate, and other soft drinks (like soda). (Weiss 71)

Draw Backs- mildly addictive and can result in withdrawal symptoms, can cause insomnia, excessive amounts can cause tremors or palpitations and feeling of anxiety, increases urination, lowers the bodies absorption of calcium. (Weiss 71)

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 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: ~headache ~fatigue ~anxiety ~irritability ~depressed mood ~difficulty concentrating

Benefits- temporary mental alertness, athletic performance because it increases muscle strength and endurance. (Weiss 71)

Limited evidence suggests caffeine may also reduce the risk of the following: ~Parkinson's disease ~iver disease ~colorectal cancer ~type 2 diabetes ~dementia

As of 2004, children ages 6 to 9 consumed about 22 milligrams of caffeine per day. However, energy drinks that contain caffeine are becoming increasingly popular. Studies suggest that up to 300 milligrams of caffeine daily is safe for kids.

Many kids are sensitive to caffeine, developing temporary anxiety or irritability, with a "crash" afterwards.

Caffeine can make you need to urinate. However, the fluid you consume in caffeinated beverages tends to offset the effects of fluid loss when you urinate. The bottom line is that although caffeine does act as a mild diuretic, studies show drinking caffeinated drinks doesn't actually cause dehydration.

Many studies show no links between low amounts of caffeine (a cup of coffee per day) and any of the following: ~trouble conceiving ~miscarriage ~birth defects ~premature birth ~low birth rate

Some people's asthma also appears to benefit from caffeine.

Other possible benefits include improved immune function from caffeine's anti-inflammatory effects and help with allergic reactions due to caffeine's ability to reduce concentrations of histamines.