Caffeine Myths and Facts
Caffeine myth or caffeine fact? It's not always easy to know. Chances are you have some real misperceptions about caffeine. For starters, do you know the most common sources of caffeine? Well, maybe two of the sources aren't too hard to name -- coffee and tea leaves. But did you know kola nuts and cocoa beans are also included among the most common caffeine sources? And do you know how much caffeine content can vary from food to food? Turns out it's quite a lot actually, depending on the type and serving size of a food or beverage and how it's prepared.
Caffeine content can range from as much as 160 milligrams in some energy drinks to as little as 4 milligrams in a 1-ounce serving of chocolate-flavored syrup. Even decaffeinated coffee isn't completely free of caffeine. Caffeine is also present in some over-the-counter pain relievers, cold medications, and diet pills. These products can contain as little as 16 milligrams or as much as 200 milligrams of caffeine. In fact, caffeine itself is a mild painkiller and increases the effectiveness of other pain relievers.
Want to know more? Read on. WebMD has examined some of the most common myths about caffeine and gathered the facts to shed some light on those myths.
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. (Although after seeing your monthly spending at the coffee shop, you might disagree!)
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:
No doubt, caffeine withdrawal can make for a few bad days. However, caffeine does not cause the severity of withdrawal or harmful drug-seeking behaviors as street drugs or alcohol. For this reason, most experts don't consider caffeine dependence an addiction.
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 consume caffeine at least 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.
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 such people as those who have high blood pressure or are older. Here are the facts:
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.
Many studies show no links between low amounts of caffeine (a cup of coffee per day) and any of the following:
At the same time, for pregnant women or those attempting pregnancy, the March of Dimes suggests fewer than 200 milligrams of caffeine per day. That's largely because in limited studies, women consuming higher amounts of caffeine had an increased risk for miscarriage.
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.
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. But is it smart? Many kids are sensitive to caffeine, developing temporary anxiety or irritability, with a "crash" afterwards. Also, most caffeine that kids drink is in sodas, energy drinks, or sweetened teas, all of which have high sugar content. These empty calories put kids at higher risk for obesity.
Even if the caffeine itself isn't harmful, caffeinated drinks are generally not good for kids.
Actually, 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 has few proven health benefits. But the list of caffeine's potential benefits is interesting. Any regular coffee drinker may tell you that caffeine improves alertness, concentration, energy, clear-headedness, and feelings of sociability. You might even be the type who needs that first cup o' Joe each morning before you say a single word. Scientific studies support these subjective findings. One French study even showed a slower decline in cognitive ability among women who consumed 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. Some people's asthma also appears to benefit from caffeine. These research findings are intriguing, but still need to be proven.
Limited evidence suggests caffeine may also reduce the risk of the following:
Despite its potential benefits, don't forget that high levels of caffeine may have adverse effects. More studies are needed to confirm both its benefits and potential risks.
original story posted at http://www.webmd.com/balance/caffeine-myths-and-facts