Caffeine Consumption: How much is too much?

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Caffeine Consumption

Caffeine content chart

How much caffeine is needed to produce an effect? Well contrary to belief, not as much as previously thought. Originally it was believed that it took 85 milligrams of caffeine to get a result, but new studies prove that it takes only 25 milligrams.

Calculating how much caffeine you consume is also rather difficult. Similarly to alcohol consumption, it’s nearly impossible to get an accurate gauge of how much caffeine you take in. A person can only get a rough estimate at best. This is because there are a number of factors that affect how much caffeine is in coffee: the brewing method, characteristics of bean, and quality of extraction.

For example, arabica beans have more flavor, but robusta beans typically have twice as much caffeine in them. One common misconception is that an espresso has more caffeine than a single cup of coffee. If you measure the amount of beans that go into one cup of coffee and one espresso, the numbers are relatively similar. Consequently, the amount of caffeine that is extracted is about the same.

Another problem with calculating caffeine consumption is the varying degrees of serving sizes. Studies show that the standard serving size is 5 - 6 oz, but the standard serving size in restaurants is 12oz. Also, most coffee bars in the U.S. typically serve espresso as double shots while in Italy only a single shot is used.

Up All Night

Insomia is a common side effect of caffeine

While some tales of caffeine are more myth than fact, some things about caffeine are very real, such as caffeine's effect on sleep. Caffeine definitely increases alertness helps keep you awake. However, even though coffee does limit the amount of total sleep time, many studies have shown that the REM (Rapid Eye Movement) stage of sleep is not decreased.

In addition, the a persons sensitivity to caffeine is dependent upon their ability to metabolize it. The body absorbs caffeine within 5 minutes of consumption, and reaches its apex in about 30 to 60 minutes. While the body tends to absorb caffeine very quickly, conversely it expels caffeine at a extremely slow rate. The time it takes to break down and expel caffeine in urine is usually around 8 to 12 hours, depending on a persons metabolic rate.

Smoking is another factor that affects a persons sensitivity to caffeine. Heavy smokers are often heavy coffee drinkers because they break down and expel caffeine at a higher rate than non-smokers. As a result, smokers have to drink more coffee to reach the same effect as non-smokers.