Natural sources of caffeine include coffee, tea, and cocoa beans. Manufacturers also add synthetic caffeine to many foods, drinks, medicines, and supplements.
People who regularly consume caffeine may experience withdrawal symptoms after suddenly quitting caffeine.
This article describes the main symptoms of caffeine withdrawal. It also discusses what caffeine withdrawal is and some tips on how to cope when reducing caffeine intake or quitting altogether.
Excessive caffeine consumption can lead to dependence.
Reducing or quitting caffeine after regular consumption can cause intense, migraine-like headaches in some people.
As a fat- and water-soluble molecule, caffeine readily crosses the blood-brain barrier where it constricts, or narrows, the blood vessels. Constricting the blood vessels causes a reduction in blood flow, which can help reduce migraine pain.
Reducing or quitting caffeine suddenly will allow the blood vessels to suddenly grow, increasing blood flow. This dramatic increase in blood flow can cause painful, throbbing headaches similar to those of migraine.
Headaches due to caffeine withdrawal can vary in length and severity. People can use caffeine to treat these headaches, but they should be careful not to consume more caffeine than they were previously.
Headaches should subside once the brain adapts to the change in blood flow.
Many people consume caffeine in the morning to boost their alertness levels. Caffeine prevents fatigue and increases alertness by blocking adenosine receptors in the brain.
Adenosine is a neurotransmitter that slows the central nervous system when the body prepares to sleep.
However, when a person suddenly stops or reduces their caffeine intake, it can briefly have the opposite effect and make a person feel more tired during the day.
People can avoid feeling overly tired during the day by getting enough sleep during the night.
Changes in mood
Caffeine can contribute to feelings of anxiety or depression.
Consuming low doses of caffeine can improve in mood and reduce feelings of anxiety. However, consuming moderate to high doses of caffeine can trigger feelings of anxiety, jitteriness, and nervousness.
These mood changes occur due to the effect that caffeine has on various neurotransmitters. These include dopamine, glutamate, and norepinephrine.
Dopamine activates pleasure centers in the brain and plays a role in regulating emotions and behaviors.
A 2015 study showed that caffeine does not directly stimulate dopamine production. Instead, it increases the number of available dopamine receptors in the brain. This may enhance dopamine's overall effect on the brain.
Glutamate promotes communication among nerve cells and plays an essential role in learning and memory.
The brain produces norepinephrine when a person senses danger or stress in a process called the "fight-or-flight" response. Norepinephrine increases heart rate, breathing rate, and blood glucose levels.
Abruptly quitting caffeine can cause a dramatic change in the chemicals present in the brain, which may cause feelings of anxiety, depression, or irritability.
Because caffeine interacts with certain chemicals in the brain, it can affect concentration and memory.
A 2019 study found that consuming just 80 milligrams (mg) of caffeine led to improvements in working memory and reductions in response time among human participants.
People may experience difficulty concentrating after abruptly quitting caffeine. In the absence of caffeine, adenosine molecules can promote feelings of fatigue that may affect a person's ability to concentrate.
Caffeine stimulates contractions in the colon and intestines. These contractions help move food and waste material through the gastrointestinal tract.
People who regularly consume caffeine may experience mild constipation after reducing their caffeine intake.
People can prevent constipation by eating fiber-rich foods and staying hydrated.
What is caffeine withdrawal?
A person who consumes caffeine regularly may build up a tolerance.
Caffeine can alter the levels of certain neurotransmitters, such as adenosine and dopamine. Changes to these neurotransmitters can affect alertness, concentration, and mood.
People who regularly consume caffeine can build up a tolerance to its effects. Some people may even develop a slight physical or behavioral dependence on caffeine.
Those who abruptly quit caffeine after regularly consuming it may experience unpleasant symptoms, such as headaches and irritability. Doctors call this caffeine withdrawal syndrome.
How to cope
People can prevent caffeine withdrawal symptoms by gradually reducing their caffeine intake over time.
A 2019 study reported that gradually reducing caffeine consumption over a 6-week period led to successful, long-term caffeine cessation with minimal side effects.
According to the findings of another study from 2019, the best method for a person to relieve caffeine withdrawal symptoms is to consume more caffeine.
To avoid or reduce caffeine withdrawal symptoms:
- Gradually reduce caffeine intake. Quitting caffeine can cause dramatic changes to brain chemistry, which may affect a person's mood, cognitive ability, and physical well-being.
- Find acceptable caffeine replacements. People who drink coffee regularly can gradually reduce their caffeine intake by mixing a little decaf into their daily coffee. People who drink multiple cups of coffee can try replacing one or more with decaf.
- Get plenty of sleep. Getting enough sleep will help fight fatigue. Feeling well-rested can help reduce the body's dependence on caffeine.
- Drink water. Staying hydrated is essential. Dehydration can lead to headaches and fatigue.
How much caffeine is too much?
The Dietary Guidelines for Americans 2015–2020 recommend that adults consume no more than 400 mg of caffeine per day to avoid unwanted side effects. This is equivalent to around four 8-ounce cups of coffee.
A 2015 study examined trends in caffeine intake among 24,808 adults between 2001 and 2010. On average, adult participants consumed 122–226mg of caffeine per day, which is well within the official recommendations.
However, findings from the study revealed that 14 percent of those who regularly consumed caffeine exceeded 400 mg per day. The study authors reported daily caffeine intakes of up to 1,329 mg per day and 756 mg in one sitting.
Caffeine is a central nervous system stimulant. Regular consumption can alter a person's brain chemistry. This can cause adverse physical and psychological reactions, such as headache and anxiety.
Caffeine directly inhibits the effects of adenosine, a neurotransmitter that causes fatigue and drowsiness. Caffeine also promotes the effects of mood-altering neurotransmitters, such as dopamine, norepinephrine, and glutamate.
Caffeine withdrawal syndrome is a medically recognized condition that occurs when people experience significant symptoms after abruptly quitting caffeine. These symptoms tend appear within a day of quitting and can last a week or more in some people.
Gradually reducing caffeine intake over several weeks instead of quitting cold turkey may help reduce caffeine withdrawal symptoms.