When it comes to caffeine and headache, the relationship is complex. In fact, even with today's medical advances, you can still find medical professionals who disagree on "the truth" about caffeine.
In an effort to continue providing you with the best possible weapons in your fight against headache — education and support — the National Headache Foundation asked a distinguished panel of experts of to take a hard look at the published evidence and explain what they found.
Caffeine: A Time Honored Agent
Caffeine is found naturally in dozens of plants from all over the world. The most widely known and used are coffee beans and kola nuts, which originally came from Africa, and tea, which first came from China.
Some others you may not know about:
- Cocoa beans, initially from Mexico
- Ilex plant, source of the drink known as mate (Paraguayan tea)
- Cassina (Christmas berry tree), a native of North America, source of a caffeine beverage among Indians from Virginia to Florida and west along the Gulf coast to the Rio Grande.
It is believed that, in ancient times, people from around the world probably chewed the seeds, bark, and leaves of the most common caffeine-containing plants. The oldest written reference to caffeine is actually a reference to tea — it was found in a Chinese dictionary from about 350 AD. According to ancient Chinese tradition, however, tea was first brewed almost 3000 years earlier, when the Emperor Shen Nung was boiling water and the leaves of a nearby bush fell into his pot.
Legend credits the discovery of coffee (as we know it) to the prior of an Arabian convent, even though the plant originates from Ethiopia. As the story goes, shepherds told the prior that whenever their goats ate the berries of the coffee plant, they stayed up all night, frolicking about, instead of sleeping. The prior, mindful of many long nights of prayer, asked the shepherds to pick the berries so that he could make a beverage from them. Some historians have suggested that coffee may have been cultivated in Ethiopia as early as the 6th century AD.
In its pure, chemical form, caffeine is a bitter, white powder. It is known as an alkaloid. Caffeine has two major chemical relatives, theophylline (treats asthma) and theobromine (promotes urination and stimulates cardiac muscle).
Effects on the Body
Caffeine has many biological effects. It increases metabolic activity and heart rate, relaxes smooth muscle (especially in and around the lungs), increases the production of urine, and stimulates the body's chemical messenger system (neurotransmitters). By increasing the production of stomach acid, caffeine helps the body absorb headache medicines faster than when no caffeine is present.
Medical Uses: more than a pick-me-up
When researchers began to understand how caffeine affects the body, a number of important medical uses were discovered. You may not know that caffeine:
- Promotes alertness (but does not improve memory)
- Helps stimulate breathing in newborns
- Can be used to treat asthma
Some formulations of caffeine are used to promote weight loss in dangerously obese individuals. Scientists have shown that coffee can be good for patients with liver disease, but the amount of coffee needed to obtain these benefits remains unclear.
The most recent research shows that compounds derived from caffeine may have the potential to treat some types of cancer.
Products that Contain Caffeine
The average American consumes about 227 mg of caffeine daily. Tea and soft drinks are the main sources of caffeine for the majority of children and young adults. As we get older, coffee becomes the primary source of caffeine in our diets. Of course, most of us know that coffee contains caffeine. But just how much caffeine is there in that "morning wakeup call"? Does a double espresso have more caffeine than a typical cup? And what other products besides coffee and tea contain caffeine?
Many people are surprised to learn that caffeine can also be found in energy drinks, candy, chocolate, as well as products like some pain relievers, cold remedies, weight-control aids, and various prescription medications.
Caffeine Content of Beverages, Food and Drugs
Food and Beverages
Coffee (8 oz)
Tea (8 oz)
Soda (12 oz)
*Content per tablet; †Over-the-counter; ‡By perscription
Why Caffeine is Good and Bad
For years, caffeine has been a key ingredient in medications developed for the treatment of pain and headache. Numerous scientific studies have shown that caffeine combined with both prescription and nonprescription ingredients is both safe and effective in treating both tension-type headache and migraine.
Keep in mind, caffeine is only safe and effective when used properly.
A Little Bit Goes a Long Way
Caffeine is known to have vasoconstrictive properties, which means that it narrows the blood vessels and restricts the blood flow. This is useful in relieving headache pain, since blood vessels tend to enlarge before the beginning of some headache pain, including pain associated with migraine.
Caffeine is also known as an "analgesic adjuvant," which means that it is an ingredient added to pain relievers to make them work more effectively. Medical research has conclusively demonstrated that caffeine, when combined with aspirin or acetaminophen, can significantly improve effectiveness in relieving tension-type headache and migraine. In fact, a review of several scientific studies estimated that, for patients with tension-type headache, caffeine plus aspirin or acetaminophen increases the pain relieving effect by 40 percent!
What does this mean for you? Some experts believe that because caffeine helps the pain relievers work better, you don't have to take as much medication to relieve your headache pain. This means you can reduce the risks of unwanted side effects, such as stomach irritation, liver disease, or even a condition known as medication overuse headache.
Too Much of a Good a Thing
Medication overuse headache is a serious condition that is named after its cause. People get it from using too much medicine for their headaches. Over time, the overused medicine stops relieving their regular headaches and starts causing a new type of headache.
In most patients, the condition develops when they take the same headache medication more than two or three times per week for a period of months or years — even if they take the recommended dose. Once the condition takes hold, taking more medicine provides no relief. And if medication overuse headache patients try to stop taking the offending medication, their headaches are often worse than ever. For most patients with medication overuse headache, the problem continues until it is treated with appropriate medical care.
Some people believe that caffeine in pain relievers is a main cause of medication overuse headache. In fact, medications that contain caffeine are not more likely to cause medication overuse headache than other pain relievers. And even though all headache medications can cause medication overuse headache if they are used too often or in amounts above the recommended dose, there is good news:
- Medication overuse headache is rare-only about 1% of the general population is affected.
- You can follow a few simple steps to help ensure the appropriate use of your medications and avoid medication overuse headache.
Education is the key to appropriate use of your pain relievers. Below are some tips that will help you reduce the risk of misusing medications. As always, if you have any questions or concerns about your medication, please consult your physician.
- Read all product labels and prescribing information carefully
- Follow the directions for use exactly
- Never exceed the maximum daily amount, unless specifically instructed to by your physician
- If your headache pain does not go away after the maximum amount of medication, consult your physician.
A Review of the Evidence
Despite the fact that there have been numerous studies conducted on caffeine, there is no compelling evidence that supports the misconception that caffeine is addictive or habit forming for the vast majority of people.
Caffeine is not an addictive drug. According to the American Psychiatric Association (which does not recognize a condition called "caffeine addiction"), addiction is characterized by:
- The inability to stop taking drugs
- Interference with everyday activities, either social or work-related
Even people who consume large amounts of caffeine do not meet these criteria. However, consuming too much caffeine can have consequences for headache sufferers. Caffeine overuse by people who have occasional migraine attacks increases the chance that their condition will become chronic. Over time, occasional attacks can become more frequent and, eventually, constant. Still, despite the widespread availability of caffeine-containing products sold for alertness, such as energy drinks, foods and, supplements, reports of deliberate caffeine abuse are extremely rare.
It is important to note that moderate caffeine consumption is completely safe, and caffeine itself is not classified as an addictive drug. For some people, depending on the amount of caffeine ingested and their individual sensitivity to caffeine, caffeine can be a mild stimulant to the central nervous system. When consumption of caffeine is stopped abruptly, some people may experience "withdrawal" symptoms, including:
- Impaired concentration/lassitude/work difficulty
- Muscle aches/stiffness
Actual rates of people suffering from withdrawal are disputed by the experts, but evidence suggests that it may be less common than previously thought. In a scientific study of more than 11,000 people, only about 11 percent of the people who consumed caffeine daily reported any withdrawal symptoms once the caffeine consumption was stopped. And only 3 percent of those with symptoms said they were severe enough to interfere with their daily activities.
Caffeine withdrawal is an uncommon condition. Still, you can take steps to limit your chances of experiencing it:
- Limit your daily consumption of caffeine. You can use the Caffeine Content Chart to figure out your current intake and decide where you can cut back.
- Don't eliminate caffeine abruptly. Gradually decreasing your caffeine consumption may help to lessen the effects of withdrawal.
- Enlist the help of family members. Friends and family can provide great support during the transition.
- Consult with your physician about the withdrawal process so you can determine the best way to use caffeine-containing pain relievers during the transition and in the future.
Get the real deal on caffeine
People have been enjoying caffeine in foods and beverages for thousands of years. Here is a quick glimpse of some of the little-known events in the history of caffeine:
- The major natural sources of caffeine are coffee beans, tea leaves, cocoa beans and cola nuts
- Tea was accidentally discovered nearly 5,000 years ago when leaves from a nearby bush fell into Chinese Emperor Shen Nung's pot of boiling water Coffee beans were originally consumed as food and used as money
- Spanish conquistadors were the first Europeans to enjoy chocolate, given to them by Aztec Emperor Montezuma in 1519 in the form of a drink
- The world's first caffeinated soft drinks were introduced in 1880
- When it was first introduced, Muslims in Arabia used coffee to help them stay awake during prolonged religious vigils
- Captain John Smith of England was the first person to introduce coffee to the Americas in 1607
- In America in 1683, 12 ounces of coffee cost the equivalent of a full meal
- The average Cafeto tree yields about 1 pound of roasted coffee per year
- Bach once composed a "coffee cantata"
- The first cafe serving coffee opened in Paris 1686
- Caffeine becomes soluble in water at 175 degrees Fahrenheit