Are you wondering exactly much caffeine is in your cup of coffee. Trying to cut down a bit, or at least know how much caffeine you are ingesting each day with your morning cup of java or afternoon pick-me-up triple espresso Latte?
A typical cup of coffee contains approximately one hundred and twelve milligrams of caffeine. There is a bit less caffeine in a shot of espresso - a typical espresso shot includes about ninety milligrams of caffeine.
Caffeine Content Varies
While these numbers are typical, the amount of caffeine in coffee can vary considerably based upon multiple factors. The primary factors affecting caffeine content of coffee and espresso include the genetics of the coffee bean varietal, the particular roasting given to the coffee beans and how the coffee is brewed.
If the coffee beans being used are Arabica coffee beans then one cup of coffee that is approximately one hundred and twenty milliliters of coffee, if it is drip-brewed, will have about 112 milligrams of caffeine. A 30 milliliter Espresso shot using Arabica coffee will have an estimated ninety milligrams of caffeine.
How Does Roasting Affect Coffee Caffeine Content?
When coffee is roasted it decreases the overall amount of caffeine in the coffee, but not significantly enough for it to be a serious way to reduce your caffeine intake.
Caffeine did not undergo significant degradation with only 5.4% being lost under severe roasting.
Choose your roast based on your personal preferences, not based on caffeine content.
Roasting does have an effect on chlorogenic acid content - possibly what contributes to many of coffee's purported health effects, but another study also shows that caffeine is relatively unaffected by roast level.
How Caffeine Metabolizes in the Human Body
Once a person consumes caffeine the body starts to metabolize it and this takes place in the person's liver. The result is three different metabolites. These three metabolites include paraxanthine (84%), theobromine (12%) and theophylline (4%).
In the first 45 minutes after consumption of the caffeine it is likely absorbed by the stomach and small intestine and begins to spread throughout the tissues of the human body.
Caffeine's Classification by the Food and Drug Administration (FDA)
Considered safe for human consumption by the FDA, caffeine is classified as a food substance with multiple uses.
All About Caffeine in Coffee - Investigating the Side Effects of Caffeine and the Symptoms of Withdrawal from Caffeine continued:
Caffeine is a stimulant and is known scientifically as a xanthine alkaloid. When it is isolated from its source it is a crystalline white substance and is very bitter.
How does caffeine affect the human body?
Caffeine affects the human body by creating chemical changes in the human brain with a whole variety of effects including an enhanced alertness and energy level.
The way this is enhanced energy and alertness is achieved by the chemical caffeine is that the caffeine pretends, or mimics, another compound which is called adenosine.
The caffeine then binds on to the adenosine receptors in the brain with the effect of halting the true adenosine from doing its job which normally would be to slow down the body's nerve impulses and bring a very sleepy feeling to the person, a natural drowsiness that is warded off by the effects of caffeine.
Caffeine Side Effects Explained and Caffeine Withdrawal Symptoms
Can Caffeine Increase the Effectiveness of Drugs?
Yes, some drugs may have an enhanced effectiveness when affected by caffeine. For example, some headache drugs include caffeine in their contents in order to help the effectiveness. This may be related to the vasodilating effects of caffeine.
Caffeine may be used in combination with ergotamine to treat cluster headaches and migraines. Some people prefer to use caffeine to overcome the sleepy qualities they feel when taking antihistamines.
Does Caffeine Have Any Hepatoprotective Properties?
Yes, in fact some people who have shown to be at high risk for liver disease have been shown to have less severe liver injury associated with increasing caffeine consumption. This may include people with obesity, hemochromatosis and alcoholisms. [source]
Because of this, people who drink coffee but want to quit caffeine may want to look into decaf coffee instead of cutting out coffee entirely, so that they can continue to benefit from its health protecting properties.
What Products Contain Caffeine, and How Much?
A tablet of Excedrin contains about sixty-five milligrams of caffeine while a regular strength caffeine tablet has about one hundred milligrams of caffeine. There are two hundred milligrams of caffeine in an extra-strength caffeine tablet.
Another example of a common product with plenty of caffeine in it is chocolate. There are about ten milligrams of caffeine in an average milk chocolate bar. Dark chocolate, by comparison, may have about 30 milligrams of caffeine. There are some dark chocolate bars that have as much as 160 milligrams of caffeine so it can vary considerably by the type and the quality of the chocolate.
Six ounces of a typical green tea will contain about thirty milligrams of caffeine while the very same amount of black tea will have about fifty milligrams of caffeine.
Amount of Caffeine in Coffee continued: You will get about thirty-four milligrams of caffeine from 12 ounces of Coke while a Mountain Dew will give you a whopping 54 milligrams of caffeine. A Red Bull energy drink has about eighty milligrams of caffeine while a Monster energy drink has about 160 milligrams of caffeine.
Does Caffeine Have Any Topical Uses?
Yes, some studies completed on ex vivo hair follicles have shown that caffeine may decrease hair growth suppression in vitro due to testosterone. In this regard caffeine may be a potential therapeutic agent in Androgenic alopecia, and caffeine has been added by some companies to their soap and shampoos.
Best K-Cup Coffees
What are the natural sources of caffeine?
Caffeine is found in nature in a wide array of plants, and it is found in plant fruits as well as plant leaves. Caffeine often serves to help the plant by working as a natural pesticide against harmful predators on the plant such as insects.
Withdrawal from Caffeine and Human Tolerance To Caffeine
People who consistently consume caffeine will gradually adapt to the continuous presence of the chemical in their body by increasing their overall number of adenosine receptors in their central nervous system. This occurs since caffeine functions as an antagonist to the receptors in the central nervous system for the neurotransmitter adenosine.
Tolerance adaptation to caffeine has the effect over time of reducing the chemical's stimulatory effects. These adaptive responses to caffeine also have the effect of making the person more sensitive to adenosine, and thus when the intake of caffeine is reduced then the adenosine's natural physiological effects will create withdrawal symptoms.
Of 49 symptom categories identified, the following 10 fulfilled validity criteria: headache, fatigue, decreased energy/activeness, decreased alertness, drowsiness, decreased contentedness, depressed mood, difficulty concentrating, irritability, and foggy/not clearheaded. In addition, flu-like symptoms, nausea/vomiting, and muscle pain/stiffness were judged likely to represent valid symptom categories. In experimental studies, the incidence of headache was 50% and the incidence of clinically significant distress or functional impairment was 13%. Typically, onset of symptoms occurred 12-24 h after abstinence, with peak intensity at 20-51 h, and for a duration of 2-9 days. In general, the incidence or severity of symptoms increased with increases in daily dose; abstinence from doses as low as 100 mg/day produced symptoms. Research is reviewed indicating that expectancies are not a prime determinant of caffeine withdrawal and that avoidance of withdrawal symptoms plays a central role in habitual caffeine consumption.
Debate Over Adenosine Receptors, Tolerance and Caffeine Withdrawal Symptoms
There is some debate in scientific circles about the increase in adenosine receptors being the main cause of building up tolerance to caffeine's stimulating effects, with some evidence pointing toward a conclusion that there are also other causes at work which help to explain people developing a tolerance to large doses of caffeine.
The Discoverer of Caffeine
The evidence is a bit fuzzy but some say that the stimulating effects of caffeine are mentioned in Chinese legends dating to about 3,000 years ago.
Firmer evidence comes from 600 BCE as a Mayan pot dating to this time contains the first clear evidence of a cocoa bean, so we know caffeine was around by this time for sure.
Who First Isolated Caffeine from Coffee?
In 1819 the German chemist Friedlieb Runge became the first scientist to successfully isolate the chemical caffeine from coffee beans. Less than one year later the French chemist Pelletier and another scientist named Caventou also isolated the chemical caffeine, and Pelletier was the one to coin the word “cafeine” which he derived from the word “cafe” meaning coffee.
Who Opened the First Coffee House?
As early as 1530 there were coffeehouses in Damascus, Syria and Istanbul.
What began the spread of coffee all around the world?
In the 1600s the Dutch became the first people to carry coffee from the ancient port of Mocha. This movement of coffee by the Dutch began the rapid spread of coffee beans around the globe and it is still spreading, most recently growing rapidly in consumption in China and other emerging markets. The Dutch were also industrious in cultivating coffee in other locations, first in Ceylon (now Sri Lanka) in 1658.
Regular caffeine consumption reduces sensitivity to caffeine. When caffeine intake is reduced, the body becomes oversensitive to adenosine. In response to this oversensitiveness, blood pressure drops dramatically, causing an excess of blood in the head (though not necessarily on the brain), leading to a caffeine withdrawal headache.
This headache, well known among coffee drinkers, usually lasts from one to five days, and can be alleviated with analgesics such as aspirin. It is also alleviated with caffeine intake (in fact several analgesics contain caffeine dosages). Even small amounts of caffeine (such as a green tea, compared to a full coffee) can do wonders to alleviate a withdrawal-induced headache.
The source of caffeine is important to consider as well. Coffee is generally considered to be healthy, due in part to its anti-oxidant properties. However, energy drinks and unregulated supplements may contain any number of other compounds that can have a negative impact, often working synergistically with caffeine.
Caffeine on its own, particularly coffee, is associated with an overall decrease in all-cause-mortality . Simply put, this means that people who drink coffee are less likely to die from all causes.
The top 10 reported symptoms of caffeine withdrawal:
- Fatigue, lethargy
- Muscle stiffness, cramping
- Brain fog, Inability to focus
- Cold-like symptoms
Often, people who are reducing caffeine intake report being irritable, unable to work, nervous, restless, and feeling sleepy, as well as having a headache. Many of these symptoms mirror having the cold or flu.
In extreme cases, nausea and vomiting has also been reported. These are very real experiences , and despite recurring jokes, can cause problems with normal functioning. If you experience severe symptoms, seek medical advice.
Is Caffeine Withdrawal Real?
In short: Yes. Negative effects from quitting caffeine have been scientifically documented in clinical studies.
Of 49 symptom categories identified, the following 10 fulfilled validity criteria: headache, fatigue, decreased energy/activeness, decreased alertness, drowsiness, decreased contentedness, depressed mood, difficulty concentrating, irritability, and foggy/not clearheaded. In addition, flu-like symptoms, nausea/vomiting, and muscle pain/stiffness were judged likely to represent valid symptom categories. 
Additionally, caffeine withdrawal is recognized by psychiatrists as a real disorder.
Caffeine withdrawal is a recognized disorder and is listed in the DSM-5. (Diagnostic and Statistical Manual of Mental Disorders)
How Long Does Caffeine Withdrawal Last?
The answer to this will depend on your level of consumption and the level you reduce your caffeine consumption to.
In experimental studies, the incidence of headache was 50% and the incidence of clinically significant distress or functional impairment was 13%. Typically, onset of symptoms occurred 12-24 h after abstinence, with peak intensity at 20-51 h, and for a duration of 2-9 days. 
That means you'll probably notice the start within 12-24 hours with the worst being the second day you after you quit. From there, it gradually gets better over the course of a week to a week and a half.
Your brain is miraculously resilient and adapts to life without caffeine in just 2 short weeks. The psychological habit of drinking caffeine can take 3 to 4 weeks to break, but can also be replaced with decaf coffee or another low-caffeine drink (eg. tea).
Reports of people having withdrawal symptoms months or years after quitting coffee or caffeine are more typically confused with general health maladies or other more drugs.
Caffeine cessation is often associated with major lifestyle changes, and as such, it can be difficult to associated symptoms directly with caffeine withdrawal. As a best practice, you should isolate factors by making changes slowly, over time, unless under the advice and guidance of a medical professional.
Compounding factors such as other medications, and major health events that lead to discontinuing caffeine, can have a misleading association with caffeine withdrawals.
If symptoms such as kidney pain appears, seek immediate medical attention.
There are no known mechanisms through which caffeine withdrawal may cause tingling. On the other hand, caffeine consumption can sometimes cause tingling due to restriction of blood flow to extremities.
While back pain is not a symptom of caffeine withdrawal, symptoms may (re)appear when caffeine use is discontinued.
This may be due to caffeine's reported analgesic affect on pain  - in english, caffeine might help alleviate (back) pain by amplifying the effect of pain killers. The re-ocurring presence of back pain may be due to synergistic effect being lost, but is unrelated to the temporary effects of withdrawal itself.
Dealing with Caffeine Withdrawal
The severity of caffeine withdrawal symptoms vary with how extreme the restriction, and a gradual reduction can do wonders in avoiding symptoms. Simply starting by replacing one cup of coffee with a decaf coffee or tea will provide a much smaller dose of caffeine, allowing your receptors to re-acclimate to lower levels. Drinking coffee (decaf) or other warm beverage (tea) instead of regular coffee helps psychologically with the well established habit.
Timing large reductions in caffeine consumption is also a useful tool. Picking a time of rest and relaxation such as a weekend or vacation can lessen the burden of symptoms like brain fog and a lack of motivation.
Hydration is also key - while coffee is a diuretic it's also mostly water, and cutting back on coffee may also inadvertently cut back on your fluid intake. Many symptoms of dehydration overlap with caffeine withdrawal including headaches, muscle soreness and leg cramping, irritability and lethargy.
Without caffeine blocking your adenoseine receptors, your body's built up levels of adenosine will lead to a lot of sleepiness. Get lots of rest! Scientists are still puzzled by why humans need sleep, aside from getting tired. According to some research from the NIH (National Institutes of Health) has indicated that sleep enables your brain to drain built-up chemical by products of working so hard (you little genius), which is good for you!
Advil or Tylenol can be an effective method of dealing with the coffee withdrawal headache and muscle pain. Other natural pain relievers such as running / exercise and even an orgasm can provide temporary relief by dilating blood vessels in the brain.
The best solution may not be totally ceasing caffeine consumption though. Coffee does have health benefits, as it contains over 1000 known compounds, with many associated with lowering blood pressure and improving cardiac function, as well as liver protection . Generally, the best coffees are grown at higher elevations will develop more healthy chlorogenic acids that are present in higher concentrations in light roasts than dark roasts. If you're a dark roast lover however, darker roasts cause less stomach acid production. A decaffeinated coffee with just 5-25 mg of caffeine will still retain a lot of its healthy chemicals and will provide health benefits in medium and dark roasts.
With these tips you can reduce the caffeine in your body and avoid the rebound of a caffeine withdrawal.
 Coffee Consumption Decreases Risks for Hepatic Fibrosis and Cirrhosis: A Meta-Analysis
Caffeine and Health. J. E. James, Academic Press, 1991. Progress in Clinical and Biological Research Volume 158. G. A. Spiller, Ed. Alan R. Liss Inc, 1984.
Xie et al “Sleep initiated fluid flux drives metabolite clearance from the adult brain.” Science, October 18, 2013. DOI: 10.1126/science.1241224