Caffeine is an excellent wake-promoting agent, and humanity discovered it's usefulness thousands of years ago, but was only named in 1821 by a French chemist, who isolated it from coffee (cafe in French) and thus named it: Cafeine.... We like to add extra "f's" in English it seems: Ca ff eine
Now just because we discovered it doesn't mean it wasn't relevant in Nature long before. Like THC in marijuana, opiates in the Poppy plant, and hallucinogenic compounds in mushroom, it was designed by plants, not as a psychoactive substance for humans, but as a deterrent, as a poison against predation. It deterred and killed specific bugs that would eat the plant otherwise. Tea bushes, coffee plants, cocoa plants (chocolate), kola nuts, yerba mate.... they all tried to stop insects from killing them by evolving the stuff and spiking their tasty leaves with it. We have taken this mild insect poison, hijacked it, and used it for our enjoyment and productivity.
Basic facts about its interaction with the human brain
(The best part of this entry):
-It works by blocking adenosine (a neurotransmitter/one the ways your brain communicates within itself). Specifically, it kind of acts like adenosine and competes with it for the receptors that normally receive adenosine... BUT it doesn't actually do anything once it lands there, effectively "reducing" the presence of adenosine perceived by your body. Normally, as you stay awake longer, adenosine builds up in the brain. It's one of the ways your brain tells itself that it has been awake and active during the day as a sort of glass-filling-up clock. When it "spills over" it starts trying to tell you to go to and stay asleep so the levels can reset. It the morning, when you wake, the levels are being pushed to their lowest by other wake-promoting chemicals. You help your body de-emphasize the appreciation of adenosine's presence by taking caffeine. Now this is a somewhat crude explanation, and keep in mind that wakefulness and sleepiness are a much more complex orchestra of such chemicals (neurotransmitters) in the brain, but this one powerful part of the picture. So caffeine blocks the receptors that normally receive adenosine, so your brain isn't getting the message from itself that you are tired.
-BUT, if you keep taking caffeine, your brain will start to realize that something is wrong... The Human Body knows there should be adenosine, so if you keep blocking the receptors for it, the Body realizes that something is amiss and will increase (upregulate) the number of receptors to detect more aggressively, the presence of adenosine, making caffeine less effective. So we should take holidays from caffeine: days here and there, weeks here and there as well, so our body can become "naive" again to it's action, making it helpful again.
-Keep in mind, by the way, that if you are one of these people that needs to cut down, you will be extra sleepy (withdrawal) while your body gets back to its normal self over the next few days, and your body stops making an overabundance of adenosine receptors.
-Also, once you are taking so much caffeine on a regular basis that your body starts making more receptors to "find" what adenosine is out there, this making caffeine less helpful, you cannot overcome it with just more caffeine. There's more to it than just receptors, but after awhile you can't just overwhelm/bully the brain with more caffeine. AND, in fact, you may still get the isolated bad side effects like cardiac arrhythmia, chest tightness, anxiety, diarrhea, tremor, etc. Some people even get depressed.
-Each person is different, regarding how much caffeine it takes for them to develop tolerance. There really is no universal average amount you can limbo under. Caffeine is good, in moderation, like sunshine.
-A growing body of evidence is revealing that caffeine likely INCREASES your ability in the short term, to perform focused tasks and judge how to perform those tasks more efficiently. BUT it likely DECREASES your ability to lay down new memories as efficiently. ****That's right, it HINDERS learning for the long term. So it is NOT good to chronically use it help you stay awake to study, or rather, you could probably study and learn more efficiently if you studied without it before noon, after a good's night rest. People with memory problems associated with dementia should NOT take caffeine-- that's a definite recommendation of mine.****
-Smoking makes your body eliminate it quicker. Some antidepressants make caffeine last longer. Liver disease makes it last longer.
-For the average person (if it is going to work at all since not everyone responds to caffeine), it starts working in just less than an hour, and as short as 20 minutes if taken on an empty stomach.
-It's half-life is 5 hours on average, but ranges from 3 or 4 hours in people who metabolize it quickly, to upwards of 8 hours and even 12 hours in some people who metabolize it slowly. AND this metabolism rate can change with age.
-For some people it is more effective a gastrointestinal motility agent (anti-constipation) than as a psychoctive stimulant.
Other Things about caffeine I think you should know:
-Migraines are a mix of an electrical phenomenon occurring in the brain and vascular changes primarily around but also in the brain. These vascular changes are a spreading wave of constriction (narrowing) and dilatation (widening) of these vessels. These changes cause many of the complex and painful symptoms of a migraine. For many people, caffeine helps resolve a headache via its constriction of vessels (how caffeine affects vessel in the brain)... although for many people, caffeine overuse precipitates a headache as well. Caffeine may also have indirect headache treatment effects through its indirect help, by making other "anti-headache" medications more effective than they might otherwise be. The help afforded by caffeine, is probably best served by a body that is more "caffeine-naive" In other words, someone who doesn't already take in a bunch of caffeine. That's why people in which caffeine does help with their headaches, should probably avoid it otherwise so it will have the best chance of helping when you really need it.
-Caffeine can cause miscarriages. 200mg and above is enough to do it, by, among other things, causing constriction of the vessels that lead to the fetus.
-Caffeine is a diuretic. Now, your kidneys will overcome this with time, after regular use, but when you drink it later in the day/evening, even in mild amounts, it can cause people to use the restroom during the night, disrupting their sleep.
-Caffeine can really hurt your dog (or other pets for that matter), because they can't metabolize it like we do
Comparative chart of coffee content in common beverages:
Your average 8 oz cup is 8cm wide by 9cm tall cup (about the height and width of the average adult hand)
Average 8oz Cup.
By the way, keep in mind that a NoDoze caffeine tablet has about 200mg.
| 8-ounce Beverage | Milligrams of caffeine |
| Coffee, Drip | 120-180 |
| Coffee, Italian Espresso (2 ounces) | 90-100 |
| Coffee, Instant | 65-100 |
| Tea, Iced | 47 |
| Tea, Brewed | 60-80 |
| Tea, Instant | 30 |
| Hot cocoa | 20 |
| Coffee, Decaf, Drip | 10-15 |
| Coffee, Decaf, Instant | 2-3 |
| 12-ounce beverage | Milligrams of caffeine |
| Red Bull (8.2 oz) | 80.0 |
| Jolt | 71.2 |
| Pepsi One | 55.5 |
| Mountain Dew | 55.0 |
| Diet Mountain Dew | 55.0 |
| Diet Mountain Dew | 55.0 |
| Diet Coke | 45.6 |
| Shasta Sodas | 44.4 |
| RC Cola | 43 |
| Dr. Pepper | 41 |
| Mr. Pibb | 40 |
| Big Red | 38 |
| Pepsi (regular) | 37.5 |
| Diet Pepsi | 36 |
| Coca-Cola Classic | 34 |
| Root Beer (unless Barq's) | 0 |
| Sprite | 0 |
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