• Larger text sizeLarge text sizeRegular text size

It’s almost midnight and Aaron has already had a full day of school, work, and after-school activities. He’s tired and knows he could use some sleep. But he still hasn’t finished his homework. So he reaches for his headphones — and some caffeine.

What Is Caffeine?

Caffeine is a drug that is naturally produced in the leaves and seeds of many plants. It’s also produced artificially and added to certain foods. Caffeine is defined as a drug because it stimulates the central nervous system, causing increased alertness. Caffeine gives most people a temporary energy boost and elevates mood.

Caffeine is in tea, coffee, chocolate, many soft drinks, and pain relievers and other over-the-counter medications. In its natural form, caffeine tastes very bitter. But most caffeinated drinks have gone through enough processing to camouflage the bitter taste.

Teens usually get most of their caffeine from soft drinks and energy drinks. (In addition to caffeine, these also can have added sugar and artificial flavors.) Caffeine is not stored in the body, but you may feel its effects for up to 6 hours.

Got the Jitters?

Many people feel that caffeine increases their mental alertness. Higher doses of caffeine can cause anxiety, dizziness, headaches, and the jitters. Caffeine can also interfere with normal sleep.

Caffeine sensitivity (the amount of caffeine that will produce an effect in someone) varies from person to person. On average, the smaller the person, the less caffeine needed to produce side effects. Caffeine sensitivity is most affected by the amount of caffeine a person has daily. People who regularly take in a lot of caffeine soon develop less sensitivity to it. This means they may need more caffeine to achieve the same effects.

Caffeine is a mild diuretic, meaning it causes a person to urinate (pee) more. Drinking a moderate amount of caffeine isn’t likely to cause dehydration, but it’s probably a good idea to stay away from too much caffeine in hot weather, during long workouts, or in other situations where you might sweat a lot.

Caffeine also may cause the body to lose calcium, and that can lead to bone loss over time. Drinking caffeine-containing soft drinks and coffee instead of milk can have an even greater impact on bone density and the risk of developing


Caffeine can aggravate certain heart problems. It also may interact with some medicines or supplements. If you are stressed or anxious, caffeine can make these feelings worse. Although caffeine is sometimes used to treat migraine headaches, it can make headaches worse for some people.

Moderation Is the Key

Caffeine is usually thought to be safe in moderate amounts. Experts consider 200–300 mg of caffeine a day to be a moderate amount for adults. But consuming as little as 100 mg of caffeine a day can lead a person to become “dependent” on caffeine. This means that someone may develop withdrawal symptoms (like tiredness, irritability, and headaches) if he or she quits caffeine suddenly.

Teens should try to limit caffeine consumption to no more than 100 mg of caffeine daily, and kids should get even less. The following chart includes common caffeinated products and the amounts of caffeine they contain:

Drink/Food/ Supplement

Amt. of Drink/Food

Amt. of Caffeine

SoBe No Fear

8 ounces

83 mg

Monster energy drink

16 ounces

160 mg

Rockstar energy drink

8 ounces

80 mg

Red Bull energy drink

8.3 ounces

80 mg

Jolt cola

12 ounces

72 mg

Mountain Dew

12 ounces

55 mg


12 ounces

34 mg

Diet Coke

12 ounces

45 mg


12 ounces

38 mg


12 ounces

0 mg

Brewed coffee (drip method)

5 ounces

115 mg*

Iced tea

12 ounces

70 mg*

Cocoa beverage

5 ounces

4 mg*

Chocolate milk beverage

8 ounces

5 mg*

Dark chocolate

1 ounce

20 mg*

Milk chocolate

1 ounce

6 mg*

Jolt gum

1 stick

33 mg

Cold relief medication

1 tablet

30 mg*


1 tablet

200 mg

Excedrin extra strength

2 tablets

130 mg

*denotes average amount of caffeine

Source: U.S. Food and Drug Administration, National Soft Drink Association, Center for Science in the Public Interest.

Cutting Back

If you’re taking in too much caffeine, you may want to cut back. The best way is to cut back slowly. Otherwise, you could get headaches and feel tired, irritable, or just plain lousy.

Try cutting your intake by replacing caffeinated sodas and coffee with noncaffeinated drinks, like water, decaffeinated coffee, caffeine-free sodas, and caffeine-free teas. Start by keeping track of how many caffeinated drinks you have each day, then substitute one of these daily drinks with a caffeine-free alternative. Continue this for a week. Then, if you are still drinking too much caffeine, substitute another of your daily drinks, again, keeping it up for a week. Do this for as many weeks as it takes to bring your daily caffeine intake below the 100-milligram mark. Taking a gradual approach like this can help you wean yourself from caffeine without unwanted side effects like headaches.

As you cut back on the amount of caffeine you consume, you may find yourself feeling tired. Be sure you’re getting enough sleep and boost your energy by exercising. As your body adjusts to less caffeine, your energy levels should return to normal in a few days.

Reviewed by: Mary L. Gavin, MD Date reviewed: September 2014


What is caffeine?

Caffeine is a bitter substance that occurs naturally in more than 60 plants including

  • Coffee beans
  • Tea leaves
  • Kola nuts, which are used to flavor soft drink colas
  • Cacao pods, which are used to make chocolate products

There is also synthetic (man-made) caffeine, which is added to some medicines, foods, and drinks. For example, some pain relievers, cold medicines, and over-the-counter medicines for alertness contain synthetic caffeine. So do energy drinks and “energy-boosting” gums and snacks.

Most people consume caffeine from drinks. The amounts of caffeine in different drinks can vary a lot, but it is generally

  • An 8-ounce cup of coffee: 95-200 mg
  • A 12-ounce can of cola: 35-45 mg
  • An 8-ounce energy drink: 70-100 mg
  • An 8-ounce cup of tea: 14-60 mg

What are caffeine’s effects on the body?

Caffeine has many effects on your body’s metabolism. It

  • Stimulates your central nervous system, which can make you feel more awake and give you a boost of energy
  • Is a diuretic, meaning that it helps your body get rid of extra salt and water by urinating more
  • Increases the release of acid in your stomach, sometimes leading to an upset stomach or heartburn
  • May interfere with the absorption of calcium in the body
  • Increases your blood pressure

Within one hour of eating or drinking caffeine, it reaches its peak level in your blood. You may continue to feel the effects of caffeine for four to six hours.

What are the side effects from too much caffeine?

For most people, it is not harmful to consume up to 400mg of caffeine a day. If you do eat or drink too much caffeine, it can cause health problems, such as

  • Restlessness and shakiness
  • Insomnia
  • Headaches
  • Dizziness
  • Rapid or abnormal heart rhythm
  • Dehydration
  • Anxiety
  • Dependency, so you need to take more of it to get the same results

Some people are more sensitive to the effects of caffeine than others.

What are energy drinks, and why can they be a problem?

Energy drinks are beverages that have added caffeine. The amount of caffeine in energy drinks can vary widely, and sometimes the labels on the drinks do not give you the actual amount of caffeine in them. Energy drinks may also contain sugars, vitamins, herbs, and supplements.

Companies that make energy drinks claim that the drinks can increase alertness and improve physical and mental performance. This has helped make the drinks popular with American teens and young adults. There’s limited data showing that energy drinks might temporarily improve alertness and physical endurance. There is not enough evidence to show that they enhance strength or power. But what we do know is that energy drinks can be dangerous because they have large amounts of caffeine. And since they have lots of sugar, they can contribute to weight gain and worsen diabetes.

Sometimes young people mix their energy drinks with alcohol. It is dangerous to combine alcohol and caffeine. Caffeine can interfere with your ability to recognize how drunk you are, which can lead you to drink more. This also makes you more likely to make bad decisions.

Who should avoid or limit caffeine?

You should check with your health care provider about whether you should limit or avoid caffeine if you

  • Are pregnant, since caffeine passes through the placenta to your baby
  • Are breastfeeding, since a small amount of caffeine that you consume is passed along to your baby
  • Have sleep disorders, including insomnia
  • Have migraines or other chronic headaches
  • Have anxiety
  • Have GERD or ulcers
  • Have fast or irregular heart rhythms
  • Have high blood pressure
  • Take certain medicines or supplements, including stimulants, certain antibiotics, asthma medicines, and heart medicines. Check with your health care provider about whether there might be interactions between caffeine and any medicines and supplements that you take.
  • Are a child or teen. Neither should have as much caffeine as adults. Children can be especially sensitive to the effects of caffeine.

What is caffeine withdrawal?

If you have been consuming caffeine on a regular basis and then suddenly stop, you may have caffeine withdrawal. Symptoms can include

  • Headaches
  • Drowsiness
  • Irritability
  • Nausea
  • Difficulty concentrating

These symptoms usually go away after a couple of days.

14 Surprising Facts About Caffeine, Explained by Science

For many of us, coffee is our best friend. It’s there in our times of need, whether a cold weekday morning or during an all-nighter. Coffee is warm, reassuring and keeps up sharp. But do we really know what coffee is doing to our brains?

Fortunately science can tell us! Did you know that scientists are the biggest coffee drinkers of all? So scientists are bound to know more than a thing or two about the magical effects of coffee.

Image Credit: I Love Coffee

Here are the essential scientific facts that everyone needs to know about drinking coffee:

1. This is what caffeine, the chemical, “looks” like.

Image Credit: Beautiful Brainiacs

The shape of caffeine is similar to an important molecule called “adenosine” that regulates brain function (pictured below). Caffeine “mimics” adenosine and binds to the same targets in the brain.

Image Credit: Wikipedia

2. Caffeine looks like this when viewed from an electron microscope.

Annie Cavanagh and David McCarthy

Caffeine naturally forms tiny crystals, about 0.0016 inch in size. This picture won a science photography award in 2012 for creatively showing an “everyday thing from a different, at first unrecognizable, perspective.”

3. These are the best times to drink coffee.

Image Credit: I Love Coffee

That’s because we’re all guided by a 24-hour biological cycle, known as the circadian clock. When you first wake up your brain is already flooded with cortisol, a natural chemical that helps to keep you alert. So although you might feel like a coffee, you don’t actually need one. Best to wait until cortisol levels drop later in the day.

4. Once you do take a sip, it takes only 10 minutes or so for the caffeine to kick in.

Image Credit: Imgur

After as little as 10 minutes, the caffeine concentration in your blood reaches half the maximum concentration, which is enough to have an effect. The caffeine reaches maximum levels, making you most alert, after 45 minutes. Depending on how fast or slow your body’s able to break down the drug, you could feel the effects of caffeine for 3 to 5 hours.

5. Caffeine works by blocking the effect of the brain’s natural regulator, adenosine.

During the day, your brain naturally builds up its levels of adenosine. When they reach a threshold concentration, they bind to special receptors that react by start firing instructions to make your body sleepy.

Image adapted from animation by Alex Wong

Remember how caffeine has a similar shape to adenosine? This means that it can bind these very same receptors, blocking the natural effect of adenosine. This allows the brain’s stimulants to work unimpeded, keeping you up and alert.

6. Caffeine affects your brain much differently than beer.

I Love Coffee

7. In addition to caffeine, there’s lots of other stuff in coffee that may be good for your health.

Authority Nutrition

That’s because coffee also contains hundreds of different compounds. These include many antioxidants that protect our bodies from damaging chemicals called “free radicals.” These molecules cause aging and are associated with illnesses such as cancer and heart disease. NIH studies show that coffee drinkers have a reduced risk of Alzheimer’s, Parkinson’s, type 2 diabetes and many other diseases.

There’s a caveat: Many coffee drinkers are also heavy smokers, heavy drinkers and red meat eaters, all things that are detrimental to your health. This means that the data above is adjusted for these risk factors, so you should avoid these habits if you want coffee to have a positive effect. Also, the research here isn’t conclusive enough to prove a causal relationship, but it’s the best data we have so far. Overall, it’s encouraging news for coffee lovers!

8. Bees also love caffeine, and it helps their brains too!


The nectar in some flowers has low levels of caffeine, which is used to attract bees by creating a drug-induced buzz that keeps the bees coming back. The caffeine is good for the bees too. Recent studies have shown that caffeine can help enhance the long term memory of bees.

9. Your brain can become unhealthily addicted to caffeine …

As you might expect, the brain is clever and not so easily tricked. In reaction to caffeine blocking all of its receptors, the brain makes even more of them so that adenosine is still able to bind its target. This means that over time, the chemistry of your brain changes so that you’ll need to drink more and more coffee just to have the same effect.

10. … Which means that you can have horrible caffeine withdrawals.


Caffeine is a stimulant to the central nervous system, and like other drugs, regular use of caffeine can cause a mild physical dependence. Caffeine withdrawal is now recognized as a mental disorder. So consume carefully.

11. There are a whole bunch of side-effects.


Quitting caffeine suddenly can cause headaches that last up to nine days. For those who want out, doctors recommend reducing consumption gradually over a period of four weeks.

12. Caffeine isn’t too great for spiders either.


In 1995 NASA tested the effect of various drugs on the ability of spiders to spin webs. As you can see the result is quite striking. Spiders can’t metabolise caffeine as well as humans, so they are much more affected by the drug.

13. Just don’t drink too much …

I Love Coffee

Admittedly 100 cups in four hours is more than a lot. Still, you’ve been warned.

14. And don’t forget to watch those calories!

Image Credit: Information is Beautiful. Hover over to scroll.

Want the alertness, but not the extra pounds? Black ice coffee gives you the most bang for your buck.

All the mental, social and health benefits probably outweigh all the negative effects and make coffee worth it.

College students who pull all-nighters may be familiar with caffeine pills, also called “alertness aids,” such as NoDoz and Vivarin, each of which contain 200 milligrams per pill.

In addition, caffeine is in some weight-loss products and dietary supplements. It may be listed on the label as guarana, kola nut, yerba mate, green tea extract or green coffee bean extract, according to the National Institutes of Health.

Coffee beans come from a red fruit

(Image credit: jaboo2foto/.com)

The fragrant brown beans that people might toss into a grinder every morning actually come from a bright-red fruit.

Coffee comes from shrubs, known as coffee cherries, that produce a red berry when ripe, Lane told Live Science. The actual coffee beans, which are green, are found inside the coffee cherries.

Coffee often has to be picked by hand because the red fruit doesn’t all mature at the same time, Lane noted.

Before the beans were used to make coffee, the pulp from the red fruit was first fermented and used to make a wine, he said. Some time around 1000 A.D., people in Arabia began to roast coffee beans to make a beverage from them.

But according to the National Coffee Association, an industry trade group, an Ethiopian goat herder named Kaldi first discovered the stimulant powers of coffee around 800 A.D., when he found his goats dancing and frolicking in the fields after grazing on the red berries from a coffee shrub. After seeing its effects on his goats, Kaldi also tried the coffee cherries. He had a similar reaction to them.

Then, a monk who supposedly observed Kaldi and his goat’s odd behavior plucked some berries and took them back to his monastery for his brothers to try that night. After consuming the fruit, they became more alert and attentive during long hours of evening prayer. According to legend, the monks came up with the idea of drying the fruits and boiling them into a beverage.

It’s as if coffee cherries were the answer to the monks’ prayers — or at least their ability to stay awake during them.

Caffeine can exaggerate the effects of stress

Employees who check email after hours report higher levels of stress. (Image credit: Stress image via )

Lane’s research has found that caffeine can amplify stress in people who consume it every day. In a small study of habitual coffee drinkers, he found that caffeine amplifies the stress response in the body, resulting in increases in blood pressure and heart rate, as well as increases in the production of stress hormones.

Caffeine directly affects not only the way a person’s body responds to stress but also the mind by magnifying an individual’s perception of stress.

An exaggerated stress response can make a difference to people with conditions such as high blood pressure and type 2 diabetes, Lane said.

In fact, he encourages people with these conditions, as well as people with prediabetes or borderline hypertension who are not yet on medication, to try eliminating coffee and other caffeinated beverages to see if it lowers their blood pressure or blood sugar levels.

Lane said lower blood pressure readings may occur within a few days of quitting caffeine, but it may take several months for people to see reductions in blood glucose.

Caffeine in plants acts as a natural pesticide and herbicide

(Image credit: joannawnuk/.com)

Caffeine is found in the leaves, fruits and seeds of some caffeine-producing plants, including coffee and tea shrubs, kola and cacao trees, guarana and yerba mate from South America.

Caffeine in plants function as a natural pesticide to help ward off insects that may attack the plants, and it may be useful in pest control, suggested a study from researchers at Harvard Medical School that was published in 1984 in the journal Science. At high doses, caffeine can even be toxic to insects.

Caffeine is also a natural herbicide that gets released into the soil so that weeds can’t grow near coffee and tea shrubs, Lane said. Weeds might compete with the shrubs for nutrients, he noted.

Lane also said that on coffee farms, caffeine can build up so much in the soil that the coffee plants themselves might suffer.

Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science.

10 Surprising Facts About Caffeine

Most of us consume it every day, but how much do we really know about caffeine? The naturally-occurring substance with a bitter taste stimulates the central nervous system, making you feel more alert. In moderate doses, it can actually offer health benefits, including boosts to memory, concentration, and mental health. And coffee in particular, a major source of caffeine for Americans, has been associated with a host of body perks, including a possible decreased risk of alzheimer’s disease and certain cancers.

But in excess amounts, caffeine overuse can trigger a fast heart rate, insomnia, anxiety, and restlessness, among other side effects. Abruptly stopping use can lead to symptoms of withdrawal, including headaches and irritability.

Here are 10 lesser-known facts about one of the most common drugs in the world.

Decaf Isn’t the Same as Caffeine Free

Image zoom

Getty Images

Think switching to decaf in the afternoon means you aren’t getting any of the stimulant? Think again. One Journal of Analytical Toxicology report looked at nine different types of decaffeinated coffee and determined that all but one contained caffeine. The dose ranged from 8.6mg to 13.9mg. (A generic brewed cup of regular coffee typically contains between 95 and 200mg, as a point of comparison. A 12-ounce can of Coke contains between 30 and 35mg, according to the Mayo Clinic.)

“If someone drinks five to 10 cups of decaffeinated coffee, the dose of caffeine could easily reach the level present in a cup or two of caffeinated coffee,” says study co-author Bruce Goldberger, Ph.D., a professor and director of UF’s William R. Maples Center for Forensic Medicine. “This could be a concern for people who are advised to cut their caffeine intake, such as those with kidney disease or anxiety disorders.”

RELATED: 10 Warm Drinks That Won’t Pack On Pounds

It Starts Working in Just Minutes

Image zoom

Getty Images

According to the American Academy of Sleep Medicine, it takes about 30 to 60 minutes for caffeine to reach its peak level in the blood (one study found increased alertness can begin in as few as 10 minutes). The body typically eliminates half of the drug in three to five hours, and the remainder can linger for eight to 14 hours. Some people, particularly those who don’t regularly consume caffeine, are more sensitive to the effects than others.

Sleep experts often recommend abstaining from caffeine at least eight hours before bedtime to avoid wakefulness at night.

It Doesn’t Affect Everyone the Same

Image zoom

The body might process caffeine differently based on gender, race, and even birth control use. New York magazine previously reported: “Women generally metabolize caffeine faster than men. Smokers process it twice as quickly as nonsmokers do. Women taking birth control pills metabolize it at perhaps one-third the rate that women not on the Pill do. Asians may do so more slowly than people of other races.”

In The World of Caffeine: The Science and Culture of the World’s Most Popular Drug, authors Bennett Alan Weinberg and Bonnie K. Bealer hypothesize that a nonsmoking Japanese man drinking his coffee with an alcoholic beverage-another slowing agent-would likely feel caffeinated “about five times longer than an Englishwoman who smoked cigarettes but did not drink or use oral contraceptives.”

Energy Drinks Have Less Caffeine Than Coffee

Image zoom

By definition, one might reasonably think that energy drinks would pack loads of caffeine. But many popular brands actually contain considerably less than an old-fashioned cup of black coffee. An 8.4-ounce serving of Red Bull, for instance, has a relatively modest 76 to 80mg of caffeine, compared to the 95 to 200mg in a typical cup of coffee, the Mayo Clinic reports. What many energy drink brands frequently do have, though, is tons of sugar and hard-to-pronounce ingredients, so it’s best to stay clear of them anyway.

Dark Roasts Have Less Caffeine Than Lighter Ones

Image zoom

A strong, rich flavor might seem to indicate an extra dose of caffeine, but the truth is that light roasts actually pack more of a jolt than dark roasts. The process of roasting burns off caffeine, NPR reports, meaning those looking for a less intense buzz might want to opt for the dark roast java at the coffee shop.

Caffeine is Found in More Than 60 Plants

Image zoom

It’s not just coffee beans: Tea leaves, kola nuts (which flavor colas), and cocoa beans all contain caffeine. The stimulant is found naturally in the leaves, seeds, and fruits of a wide variety of plants. It can also be man-made and added to products.

Not All Coffees Are Created Equal

Image zoom

When it comes to caffeine, all coffees are not created equal. According to a recent report from the Center for Science in the Public Interest, popular brands varied widely when it comes to the jolt they provided. McDonald’s, for instance, had 9.1mg per fluid ounce, while Starbucks packed more than double that at a full 20.6mg. For more on those findings, .

The Average American Consumes 200mg of Caffeine Daily

Image zoom

According to the FDA, 80 percent of U.S. adults consume caffeine each day, with an individual intake of 200mg. To put that in real world terms, the average caffeine-consuming American drinks two five-ounce cups of coffee or about four sodas.

While another estimate puts the total closer to 300mg, both numbers fall within the definition of moderate caffeine consumption, which is between 200 and 300mg, according to the Mayo Clinic. Daily doses higher than 500 to 600mg are considered heavy and may cause problems such as insomnia, irritability, and a fast heartbeat, among others.

But Americans Don’t Consume the Most

Image zoom

According to a recent BBC article, Finland takes the crown for the country with the highest caffeine consumption, with the average adult downing 400mg each day. Worldwide, 90 percent of people use caffeine in some form, the FDA reports.

You Can Find Caffeine in More Than Just Drinks

Image zoom

According to one FDA report, more than 98 percent of our caffeine intake comes from beverages. But those aren’t the only sources of caffeine: Certain foods, such as chocolate (though not much: a one-ounce milk chocolate bar contains only about 5mg of caffeine), and medications can also contain caffeine. Combining a pain reliever with caffeine can make it 40 percent more effective, the Cleveland Clinic reports, and can also help the body to absorb the medication more quickly.

More on Huffington Post Healthy Living:

The Tastiest Way to Soothe Sore Muscles

Top New Workout Headphones of 2013

6 Things You Didn’t Know About Avocados

  • By Huffington Post Healthy Living Editors

Download the Fact Sheet

Update: In 2019, the USDA updated database values for caffeine content in foods and beverages. You can learn more here.

Many of us enjoy a daily pick-me-up, such as a freshly brewed cup of coffee, an ice cold soft drink, a hot cup of tea, or an energy drink all sharing a common ingredient: Caffeine.

People all over the world have enjoyed foods and beverages containing caffeine for over a thousand years. It is one of the most studied food ingredients. Even so, misperceptions about this food ingredient continue. Given the buzz about caffeine, IFIC Foundation is providing science-based information on common questions about caffeine, its use in foods and beverages, and its effect on health.

Is caffeine safe?

Decades of research have found that moderate amounts of caffeine consumed by the general healthy population are safe and do not harm health. Caffeine’s safety is supported by its long history of consumption and extensive studies on its safety.

How is caffeine used and regulated in foods and beverages?

Caffeine may be used to impart a bitter taste to some food and beverage products, and some products may also contain caffeine for its well-known pick-me-up qualities. The U.S. Food and Drug Administration (FDA) classifies caffeine as Generally Recognized as Safe (GRAS). GRAS ingredients must meet one of the following requirements: 1) The ingredient’s safety was established before 1958, based on a history of safe use and consumption by a significant number of consumers or 2) Scientific data and information about the safety and use of the ingredient is widely known and publicly available (through scientific articles, etc.), and there is consensus among scientific experts that the ingredient is safe for its intended use. Caffeine is required to be listed in the ingredients list on food and beverage product labels, and some manufacturers also choose to list the quantity of caffeine on product labels as well.

Did You Know?

  • Coffee originated in Africa around 575 A.D., where beans were used as money and consumed as food.
  • The world’s first caffeinated soft drinks were created in the 1880s.

How much caffeine is considered ‘moderate’ for healthy adults?

Moderate caffeine consumption is considered to be in the range of 300-400 milligrams per day (mg/day), or about three to four 8-ounce cups of home-brewed coffee per day. According to FDA, the European Food Safety Authority, and Health Canada, caffeine consumption of up to 400 mg daily is not associated with adverse health effects in the general healthy population of adults.

How much caffeine do people consume each day, on average?

Recent caffeine intake studies show that the average American’s caffeine consumption is below moderate levels, with a 2014 study showing average daily caffeine consumption of 165 milligrams. This study also found that the average caffeine intake among children is low, at just 24-27 mg/day. (A study of caffeine intake in children and adolescents ages 2-16 from 1999-2010 found the primary sources of caffeine for this age group are carbonated soft drinks and tea.)

Has the introduction of energy drinks to the market changed how much caffeine people consume?

A 2010 study conducted for the FDA found that average daily caffeine intake did not change significantly between 1999 and 2010, despite the introduction of energy drinks and other foods and beverages containing added caffeine. In addition, the study found that just four percent of all consumers consume energy drinks.

How can I tell how much caffeine I am consuming?

Information about the amount of caffeine in common caffeinated foods and beverages is available from many sources, including manufacturers’ websites. Some manufacturers also provide caffeine content information on the product label. See the chart below for a general range of caffeine content in common caffeine-containing foods and beverages.

It is important to tally the caffeine from all sources you consume throughout the day to ensure you stay at or below the moderate range of 300-400 milligrams. Remember to look at the serving size provided on the label and, if you consume more than one serving, factor this in to your total caffeine intake for the day. Non-food products, such as some medications, may also contain caffeine, so it is important to include these products in your calculations.

How does caffeine fit into a healthful diet?

Caffeinated foods and beverages can be consumed by the general healthy population. Caffeine is found in various foods and beverages that can be consumed as part of an overall healthful diet, along with regular physical activity. Knowing how much caffeine you are consuming each day from all sources will help ensure you are consuming moderate amounts.

While caffeine is not an essential nutrient, moderate caffeine consumption has been associated with reduced risk of some non-communicable diseases, such as type 2 diabetes, some cancers, and Alzheimer’s disease.

Whether it’s a latte, soda, or energy drink, when enjoying a caffeinated beverage, keep the amount of caffeine per serving in mind. Despite common misperception, an 8-ounce energy drink contains about the same amount of caffeine as an 8-ounce cup of home-brewed coffee* – about 100 milligrams (Remember, moderate daily consumption is 300-400 mg for the average healthy adult).

Some people may need to avoid or limit caffeine consumption due to a health condition or individual sensitivity. Certain sensitive groups, such as pregnant women and those with a history of heart attack or high blood pressure, should talk with their healthcare professional about their caffeine consumption to determine the amount that is best for them.

*Note that coffee house brews typically contain more caffeine per serving than home brewed coffee.

Quick Facts About Caffeine

  • Caffeine is a naturally-occurring substance found in the leaves, seeds, and/or fruit of more than 60 plants.
  • Coffee and cocoa beans, kola nuts, and tea leaves are used to make beverages such as coffee, tea, cola drinks, and chocolate.
  • Caffeine is used as a flavoring ingredient in a variety of beverages.

Can some people be more sensitive to caffeine than others?

Yes, people do differ in their sensitivity to caffeine. While children, pregnant women, and those with a history of heart attack or high blood pressure are among those who may be more sensitive to caffeine than others, there are also differences in individual sensitivity among the general population.

Those concerned about experiencing undesirable effects of over-consuming caffeine, such as sleeplessness, anxiety, and jitters can limit their caffeine intake based on the amount and timing of consumption. For example, some people may choose to avoid consuming caffeine prior to bedtime in order to limit disruption of sleep.

Some people find that regularly consuming foods and beverages with caffeine may decrease their sensitivity to caffeine’s effects over time.

Does caffeine improve mental alertness?

Research shows that caffeine can increase mental alertness at work or while studying and can enhance performance on certain mental tasks. In addition to alertness and mental performance, caffeine may also improve memory and reasoning in sleep-deprived people. Caffeine will not give you unusual or “superhuman” abilities, but instead may help you reach your peak mental alertness.

Does caffeine improve athletic performance?

Caffeine has been shown to improve athletic performance, including improving endurance and delaying fatigue. Just one cup of coffee, or an equivalent amount of caffeine, has been found to have a beneficial effect on some aspects of athletic performance, and studies of cyclists found various forms of caffeinated beverages to be effective for improving performance. Similar to caffeine’s effect on mental alertness, caffeine can help an athlete achieve their peak performance, but not a level of performance that would be above their current physical capability.

Are caffeinated beverages dehydrating?

No, caffeinated beverages do not cause dehydration and in fact can contribute to hydration. While caffeine itself has a mild diuretic effect, this is offset by the liquid in the beverage. The Institute of Medicine (IOM) has concluded that caffeinated beverages, including coffee, tea, and soda, can contribute to total daily water intake.

Can pregnant women consume caffeine?

The FDA, European Food Safety Authority, as well as credible health organizations such as the March of Dimes and the American College of Obstetricians & Gynecologists have stated that some caffeine is generally safe for pregnant and nursing women. They suggest pregnant or nursing women limit consumption to no more than 200 mg/day (or two 8-ounce cups of home-brewed coffee per day).

Studies have found that moderate amounts of caffeine do not cause adverse effects like miscarriage, preterm delivery, birth defects, or low birth weight.

Pregnant and nursing women should discuss their diet with their physician and/or health professional to ensure proper nutrition for them and their babies.

Can you be “addicted” to caffeine?

Those who say they are “addicted” to caffeine tend to use the term loosely, like saying they are “addicted” to chocolate, running, working, or television. However, evidence of true addiction such as that associated with addictive drugs of abuse has not been found in studies of caffeine.

Some people may experience mild, temporary effects from abruptly stopping caffeine consumption, including headache, restlessness, and irritability. However, experts agree that discomfort can be avoided by gradually decreasing caffeine intake over time.

Does caffeine increase risk of heart disease?

A large population study found that caffeine does not increase the risk of coronary heart disease. However, those with a history of heart attack, cardiovascular disease, and/or high blood pressure should talk to their healthcare professional if they have concerns about their caffeine intake.

Does caffeine increase blood pressure?

Caffeine does not cause chronic high blood pressure (hypertension) or any persistent increase in blood pressure. Some sensitive individuals may experience a temporary increase in blood pressure from consuming caffeine; however, studies have found this increase to be modest and less than that experienced from climbing a flight of stairs.

Common Foods and Beverages that May Contain Caffeine

Favorably reviewed by the American Association of Nurse Practitioners

11 surprising facts you may not know about caffeine

March is both Caffeine Awareness Month and National Nutrition Month, an appropriate time to take an updated look at the world’s most consumed “pick-me-up.” Caffeine consumption is widespread in the United States, with 85 percent of the population drinking at least one caffeinated beverage per day. This year, for the first time in its 35-year history, the official U.S. Dietary Guidelines for Americans includes findings and recommendations on caffeine.

Here are relevant facts that many Americans might not know about caffeine, including the latest recommendations from the 2015-2020 Dietary Guidelines for Americans.

  1. Caffeine has been consumed by humans for thousands of years. It is reported that tea was first consumed in China as early as 3000 BC, and there is evidence of coffee consumption as early as the 9th century in Ethiopia. So, humanity has had a caffeine predilection for a long time. Caffeine is found naturally in over 60 plants including coffee beans, cocoa beans, tea leaves, kola nuts, yerba mate, and guarana. It is also produced synthetically and added to other products including soft drinks and energy drinks. However, there is no difference between the naturally occurring caffeine in plants and synthetic caffeine.
  2. Americans are not alone in their enjoyment of a cup of joe! Large parts of the world’s population consume caffeine in one form or another, every day. Countries that consume the most caffeine include places like Sweden, Norway, Denmark, and the Netherlands.
  3. There appears to be widespread agreement regarding the safety of a moderate daily intake level of caffeine for healthy adults of 400 milligrams (mg). The recently released Dietary Guidelines conclude that moderate coffee consumption (up to 400 mg/day of caffeine) can be part of a healthy diet. Health Canada and the European Food Safety Authority have also declared moderate caffeine intake of up to 400 mg/day safe.
  4. The vast majority of Americans consume far less than 400 mg/day of caffeine. According to the Dietary Guidelines, average intakes of caffeine among adults range from 110 mg/day (for women ages 19-30) up to 260 mg/day (for men ages 51-70). Average intakes for children (5-32 mg/day) and teens (63-80 mg/day) are lower.
  5. Consumption has remained consistent. Despite concerns expressed by some about proliferation of caffeine in the food supply, U.S. dietary patterns indicate that caffeine intake has remained steady over the past decade.
  6. Most of our intake of caffeine in the United States continues to come from coffee, tea, and soda. This is consistent with a recent FDA-sponsored study that found between 70 and 90 percent of caffeine intake is from coffee and tea.
  7. Consuming 400 mg is probably harder than you think. The Dietary Guidelines confirm that caffeinated beverages can vary in caffeine content. So consumers should be aware of how much caffeine is in commonly consumed beverages. To assist, the following examples illustrate how much you would have to drink to reach 400 mg of caffeine.
    • 16.6 servings of green tea (24 mg caffeine/8 fl. oz.)
    • 11.5 servings of brand cola (average 35 mg caffeine/8 fl. oz.)
    • 8.5 servings of black tea (47 mg caffeine/8 fl. oz.)
    • 5 servings of Red Bull energy drink (80 mg caffeine/8.4 fl. oz.)
    • 4.2 servings of regular brewed coffee (95.2 mg caffeine/8 fl. oz.)
    • 2.2 servings of coffee house coffee (180mg caffeine/8 fl. oz.)
    • 2 servings of 5-Hour Energy (200 mg caffeine/2 fl. oz.)
    • 1 serving of 10-Hour Energy shot (422 mg caffeine/2 fl. oz.)
  8. Surprise! The darker the coffee roast, the less caffeine it has. For tea, it’s the opposite: the darker the tea, the higher the caffeine content.
  9. Caffeine is one of the most thoroughly studied substances in the human diet. Over time, scientists have scrutinized, studied, and dissected caffeine; it has been surveyed, assessed and analyzed by chemists, toxicologists, and statisticians; and importantly, the effects of caffeine have been examined, discussed, and experienced first-hand by the billions of people that consume coffee, tea, chocolate, cola, or energy drinks on a daily basis. While it has been suspected of various harmful effects, for the most part, it has been exonerated. The 2015-2020 Dietary Guidelines finds strong and consistent evidence that moderate caffeine consumption in healthy adults is not associated with an increased risk of major chronic diseases (e.g., cancer, heart disease) or premature death.
  10. Caffeine isn’t for everyone. There are some people who should limit their caffeine intake. The Dietary Guidelines recommend that pregnant women, those who may become pregnant, and those who are breastfeeding should consult their health care providers for advice concerning caffeine consumption. Although the Guidelines are silent on other populations, everyone is different when it comes to caffeine. Children and teens should generally consume less caffeine due to weight concerns (and parents should monitor). Health Canada, for example, recommends specific ranges for different age groups. In addition, those who are especially sensitive to caffeine may want to limit their intake, and while caffeine is great to help get your morning started, it shouldn’t be used as a replacement for sleep.
  11. Some animals should not consume caffeine. Dogs, cats, and birds cannot metabolize caffeine, so don’t feed your pets chocolate or anything with caffeine!
  12. Cold brewed coffee products are gaining popularity. Given the extended steeping time during manufacture and processing, these products tend to have higher caffeine concentrations. An example of this is Chameleon Cold Brew, which contains a huge 2,160 mg of caffeine per 32 fl. oz. bottle. While the product label recommends consuming this as eight servings, it is still an excessive amount of caffeine to have in one container, and amounts to 270 mg per serving.
  13. Caffeine is sometimes found in surprising places like orange soda, lemonade, and enhanced water beverages.
  14. Caffeine is caffeine. The Dietary Guidelines treat caffeine holistically, focusing on the ingredient itself, whether naturally occurring, synthetic, or a combination of both–versus individual caffeinated products. We agree with this approach. Caffeine is the same, regardless of the food or beverage.

We believe that all products containing caffeine should declare the amount of caffeine per serving–and per container–on the label. To be able to track caffeine intake, using the 400 mg/day moderate level of intake as a maximum for recommended intake, consumers need to know how much caffeine is in the foods and beverages they consume. But, that can be an issue, particularly for products like energy shots and the new wave of highly caffeinated cold brew coffee products.

FDA currently requires food labels to disclose added caffeine as an ingredient, but the label is not required to provide the amount of caffeine. Very few products voluntarily list the amount of caffeine they contain, although some companies, like Red Bull and Monster, and some soft drinks, provide this information voluntarily. Because caffeine is not a nutrient, it is not listed in the Nutrition Facts label. But, would it be so hard to provide caffeine content elsewhere on the information panel?

As in all things, a little common sense goes a long way and sensitivity levels can vary from person to person. We likely all know someone who can drink an espresso after dinner and still fall asleep, while other friends may not be able to drink a Diet Coke in the afternoon without it affecting their sleep quality. Let your individual sensitivity to caffeine be your guide.

National Nutrition Month is an annual initiative led by the Academy of Nutrition and Dietetics.
DISCLOSURE: while researching facts for this blog, approximately 220 mg of caffeine (3 cappuccinos) was consumed.

  1. Seventy-three percent of U.S. kids consume caffeine on any given day, according to a 2014 Pediatrics paper; a Yale study found that middle-schoolers who imbibe energy drinks are at a 66 percent higher risk for hyperactivity than their peers who abstain. Kids’ caffeine usage is also linked to depression and substance abuse.

  2. Adults suffer too. Caffeine withdrawal was added to the Diagnostic and Statistical Manual of Mental Disorders in 2013. “It’s seen frequently, often alongside anxiety disorders,” says David Salvage, a New York psychiatrist who specializes in addiction.

  3. Even more alarming is the growing popularity of powdered pure caffeine, readily available in bulk on eBay. In 2014, the Food and Drug Administration, spurred by two lethal overdoses, warned that people should avoid the stuff, but an outright ban is unlikely.

  4. One teaspoon of powdered pure caffeine is equivalent to roughly 25 cups of coffee.

  5. One of the barriers to safe con­sumption is that regulation is all over the place, says Murray Carpenter, author of Caffeinated. “If you put 200 milligrams of caffeine powder into a 5-hour Energy Shot, it’s regulated as a supplement,” he says. But press it into a tablet, like NoDoz, and it’s an over-the-counter medication. Blend it into six soft drinks and it’s a food.”

  6. Even the military, which has long used caffeine-enriched foods to increase soldier alertness, is researching new methods for mental boosts, says Betty Davis, leader of the Performance Nutrition Team at the U.S. Army Natick Soldier Systems Center in Massachusetts. “We’re looking to see if improving soldiers’ gut health with dietary compounds is a good alternative,” she says. Their findings could ultimately yield better, safer energy for the masses.

Coffee Lovers: 13 Impressive Coffee Facts & Effects of Caffeine

We love coffee. To help us wake up in the morning, for a short mid-morning break or while chatting with friends in the afternoon. This brown beverage keeps popping up in our everyday life. With good reason, as we link coffee to pleasure.

Most people don’t know, however, that coffee is similar to cocaine and can even be lethal. Check out these interesting coffee facts we researched for you:

  1. The effects of caffeine start showing 15-20 minutes after the first sip.
  2. Caffeine affects our brain in a similar way to cocaine.
  3. Coffee beans come from the coffee plant’s red berries.
  4. Withdrawal symptoms manifest in the first 12 to 24 hours and they can last for up to 9 days.
  5. A cup of coffee contains approx. 100 mg of caffeine.
  6. If you drank 100 cups of coffee within four hours, you would die.
  7. Moderate coffee consumption during pregnancy is okay (always check with your doctor).
  8. The effects of painkillers are increased by up to 40% when combined with caffeine.
  9. Your daily caffeine dose shouldn’t exceed 400 mg.
  10. 12- to 17-year-olds constitute the most rapidly growing group of coffee consumers.
  11. Smokers metabolize caffeine up to 50% faster than non-smokers. Here are some tips on how to quit smoking!
  12. Finnish people drink the most coffee worldwide.
  13. Caffeine is processed faster in women than in men.

Do you know some more interesting coffee facts? Share them in the comments.


10 facts about caffeine

Leave a Reply

Your email address will not be published. Required fields are marked *