Caffeine and you

How much caffeine is too much, where it comes from, and just why
does it make that final paper seem so interesting?

Caffeine. One molecule that helps you get up in the morning, survive early classes, plough through a paper, and makes chocolate that much better. OIt also does a lot more to your body than you probably know about.

Caffeine is a central-nervous system stimulant which temporarily increases alertness. It is considered a psychoactive drug, any drug that crosses the blood-barrier into the central nervous system and affects brain function, but is specifically a stimulant. Nicotine and cocoa are other types of legal stimulant psychotropic drugs. Khat and coca however are not legal, and amphetamines are most frequently used for prescription drugs such as Aderall.

The most common types of effects from caffeine deal with wakefulness and alertness; the user feels less tired, and thus more awake, and their concentration increases. This happens because caffeine blocks the receptors for the nucleoside Adenosine in the brain, which is responsible for promoting sleep and arousal levels which naturally decrease each hour a person is awake.

Caffeine is also responsible for increasing dopamine in the brain, a neurotransmitter that deals with mood and attention span to at least make you happy while you’re forced to pay attention to the task at hand.

Over the years, multiple studies have been conducted to determine whether or not caffeine can be linked to preventing various diseases. The results of these tests have shown that caffeine may be linked to a reduction in cardiovascular disease, diabetes, Parkinson’s disease, and a delay in the onset of certain cancers.

But like any other drug, there are also occasional effects that are not as beneficial. Caffeine has also been found to increase blood pressure, produce a lack in fine motor functions that result in small hand-shaking, over-urination, anxiety, and trouble sleeping. Caffeine can also limit a woman’s chance of getting pregnant, but depending on your situation this could be a benefit or downside.

The worst side-effect of caffeine may be the withdrawal symptoms – headaches, irritability, sleepiness at inappropriate times, lethargy beyond not wanting to write your final paper, depression and lack of concentration. They seem to last forever and can be reversed either by consuming more caffeine or waiting it out; after all, caffeine is addictive.

The best way to combat withdrawal and come off of a caffeine addiction is gradual limitation, not cold turkey. The body will react more adversely if it is violently pulled from its source of caffeine. Instead, try cutting back a little each day or each week.

So, let’s say you want all the benefits of caffeine but none of the downsides – how would you accomplish this?

First you would need to know how much caffeine you’re drinking and how quickly you metabolize it. Caffeine is measured in milligrams (mg). An average dose of caffeine, a dose which produces the least amount of side-effects, ranges from 85-250 mg. High doses fall between 250-500 mg, and any amount higher can potentially produce caffeine toxicity.

Average to high doses create the alertness and concentration previously mentioned, but elevated doses are more likely to cause restlessness instead of concentration and hyperactivity rather than alertness. Higher doses can also increase the lack of fine motor skill coordination and make hand-shakes progress to tremors.

The amount of caffeine in each style of beverage can greatly vary, and even the amount within each type of drink contains varying amounts. The FDA lists the caffeine content of a cup of coffee to range between 60 and 150 mg of coffee depending on the brand and roast; a cup of Starbucks brewed coffee has been measured to contain 160 mg of caffeine while a cup of Dunkin Donuts has 103 mg. So, if the average dose of caffeine is between 85 and 250 mg, that can translate to anywhere up to three or four eight-ounce cups of coffee.


Once caffeine enters the bloodstream, through body membranes such as the mouth and the stomach lining, it has a half-life of about three to five hours. It only takes about 45 minutes for 99% of the consumed caffeine to be absorbed through these membranes.

Caffeine then leaves the body once it is passed through the kidneys and filtered and urinated out. It also has a dieuretic effect, causing the body to expell more water as it passes out the caffeine, which also dehydrates the body.

As soon as the caffeine has left the body, the brain’s neurotransmitters are allowed to return to normal, flooding the body with Adenosine to regulate sleepiness and giving the feeling of a crash in energy.

The amount of time it takes to metabolize the caffeine from your body varies from each person – there is no universal metabolic equation like there is for alcohol. So it’s hard to tell if that fourth cup of coffee will be too much based solely on how much you have already consumed.

The easiest way to tell how much caffeine is too much is to judge how you’re feeling. If you’re tired, unattentive and sluggish you could probably do well with a pick-me-up. If you’re awake, attentive, and determined to finish that project you put off until the last minute, you’re fine. If you can’t sit still, having trouble typing your paper through shaky hands, and you’re feeling anxious you should probably switch to water.

You can’t go wrong with water.

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