Caffeine
Also known As:
Coffee, joe, brew.
What is it?
Caffeine is the world’s most popular drug. Caffeine occurs naturally in products such as coffee, tea, chocolate and cola soft drinks, and is added to a variety of prescription and over-the-counter medications, including cough, cold and pain remedies. Energy drinks may contain both naturally occurring and added caffeine (CAMH, 2011).
The following are typical amounts of caffeine in products you may use regularly. (A cup refers to a small take-out cup size of 237 mL [8 oz]. Keep in mind that coffee and tea are often served in much larger cups.)
cup of brewed coffee: 135 mg
cup of instant coffee: 76–106 mg
cup of decaffeinated coffee: about 3 mg
cup of tea: 43 mg
can of regular cola soft drink containing caffeine (355 ml): 36–50 mg
can of energy drink (250 ml): 80 mg
dark chocolate (28 g): 19 mg
milk chocolate (28 g): 7 mg
packet of hot chocolate mix: 7 mg
stay-awake pills: 100 mg
To find out the amount of caffeine in headache and cold medicines, check the label of over-the-counter medication, or ask your pharmacist about caffeine in prescription drugs (CAMH, 2011).
In Canada, manufacturers of products that contain naturally occurring caffeine are not required by law to list caffeine as an ingredient on the label. Only added caffeine must be listed. Because some of the caffeine in energy drinks may come from plant ingredients, such as yerba mate (Ilex paraguariensis) and guarana (Paullinia cupana), caffeine may not be listed on the label (CAMH, 2011).
How does it work?
Caffeine stimulates the brain, elevates the mood and postpones fatigue. It also enhances performance at simple intellectual tasks and at physical work that involves endurance, but not fine motor co-ordination. (Caffeine-caused tremor can reduce hand steadiness.) If you consume caffeine before bedtime, you will likely take longer to get to sleep, sleep for a shorter time and sleep less deeply (CAMH, 2011).
Contrary to popular belief, drinking coffee will not help you to “sober up” if you’ve had too much alcohol. The caffeine will make you more alert, but your co-ordination and concentration will still be impaired (CAMH, 2011).
Caffeine would be classified as a central nervous system (CNS) stimulant, with the most noticeable effect on your cognition being alertness (HealthLine, 2017). Once it has been consumed, it also increases the amount of acid in your stomach and may cause heartburn or upset stomach. Caffeine is absorbed through your stomach and reaches its highest levels in your bloodstream within 1-2 hours. It can make your blood pressure go up for short time after consumption, but there have been few long-term effects on blood pressure, unless you have a pre-disposition for high blood pressure or irregular heart rhythms (HealthLine, 2017).
Your liver processes any excess caffeine that you have consumed since our bodies are not able to store excess caffeine and is then excreted through urination. This is why you are likely to have to urinate shortly after consuming caffeine (HealthLine, 2017).
What does it look like?
In its pure form, caffeine is a white, bitter-tasting powder (CAMH, 2011). Caffeine is usually consumed orally through a beverage that contains caffeine as one of its components such as coffee, tea, and energy drinks. Caffeine is also present in a number of other foods such as chocolate, kola nuts, and guarana berries. The taste varies on the type of beverage or food you consume and the other ingredients that comprise it.
Is there a safe dose?
Everyone has different sensitivities to caffeine based on age, tolerance, and medical history. Moderate amounts of caffeine—up to about 400 mg a day (e.g., about three 237 mL cups of coffee)—will rarely harm an otherwise healthy adult (CAMH, 2011). It is recommended that children, pregnant and nursing women, and people with certain heart conditions limit their caffeine consumption.
Effects
Caffeine is used as an aid to combat grogginess/keep someone alert, whether that is upon waking, or throughout the day and is the most commonly used drug across the world. It also suppresses your appetite, so it has been used (in combination with other substances) as a weight loss supplement. At moderate doses, it can elevate your mood, postpone fatigue, enhance performance at simple intellectual tasks and at physical work that involves endurance (CAMH, 2011).
Effects include:
Elevated Mood
Increased Alertness
Physical effects include:
Increased Heart Rate
Appetite Suppression
How long does the feeling last?
When taken in beverage form, caffeine begins to take effect within five minutes, and reaches its peak effect in about 30 minutes. It takes about four hours for half of a given dose of caffeine to be metabolized by the body. Normally, almost all ingested caffeine is metabolized, and there is no day-to-day accumulation of the drug in the body (CAMH, 2011).
Side effects and cautions
If you regularly drink more than six to eight cups of coffee—or your daily dose of caffeine, from various caffeine-containing products, is higher than 600 mg—you may have trouble sleeping and feel anxious and restless. Higher amounts can cause extreme agitation, tremors and a very rapid and irregular heartbeat. Consuming more than 5,000 mg over a short time can be fatal. This amount is the equivalent of about 40 cups of coffee (CAMH, 2011).
Too much caffeine can cause headaches, upset stomach, nervousness/jittery, twitching of the muscles, and insomnia. Larger doses of caffeine, especially when consumed by people who don’t usually take caffeine, can cause rapid or irregular heartbeat, breathing troubles, convulsions and even delirium (CAMH, 2011).
Is it addictive?
Regular use of caffeine can make you physically dependent on caffeine. That means that if you abruptly stop using caffeine-containing products, you may feel edgy and tired and have a bad headache. These symptoms usually appear 18 to 24 hours after the last use of caffeine, and gradually fade over the following week.
When Is it dangerous?
Consuming more than 5,000 mg over a short time can be fatal. This amount is the equivalent of about 40 cups of coffee. Combining high doses of caffeine with alcohol can be dangerous because caffeine can make you feel less intoxicated, so you may continue to drink more or to behave in ways that are risky to you and others.
Energy drinks containing caffeine should not be confused with sports drinks. When used during periods of intense physical activity, sports drinks can help to quench thirst, while energy drinks can cause dehydration.
Small amounts of caffeine have a greater effect on children because of their smaller body size. Health Canada recommends that caffeine intake from chocolate products, soft drinks and medications be limited to 45 mg for children aged four to six, 62.5 mg for children aged seven to nine and 85 mg for children aged 10 to 12. Older children should limit their intake to 2.5 mg/kg of body weight.
Although caffeine has not been proven to cause birth defects, too much caffeine can increase the risk of miscarriage and of the baby having a low birth weight. Caffeine is excreted in breast milk. Babies of mothers who drink large amounts of caffeine while nursing may be irritable and sleep poorly. Pregnant and nursing women are advised to limit their caffeine intake to no more than 300 mg a day, or a little less than two cups of coffee (CAMH, 2011).
Therapeutic Uses?
Studies have found that people who drink coffee regularly have a lower risk of developing Alzheimer’s and dementia, and cut suicide risk by 45 percent. These benefits are limited to people who drink high-octane coffee, not decaf (HealthLine, 2017).
Harm Reduction Tips
In order to reduce the possible harms of CAFFEINE, the following is suggested by CAMH (2011);
Limit your caffeine consumption to roughly 400mg a day and do not mix with alcohol.
If you are pregnant or nursing, or have a history of high blood pressure or heart problems, limit your caffeine consumption below that of the 400mg dosage.
Do not attempt to sober up with caffeine. The stimulating effects of caffeine do not sober you up. You may feel more awake and alert, but your coordination and motor functions will still be impaired by the alcohol you have consumed.
Get enough sleep. Caffeine will not substitute for rest and caution should be taken when operating vehicles or dangerous equipment without adequate sleep.
Legal Status
Unlike many other psychoactive substances, caffeine is legal and unregulated almost universally across the world.
References
Centre for Addiction and Mental Health (CAMH). (2011). Caffeine. Retrieved from https://www.camh.ca/en/health-info/mental-illness-and-addiction-index/caffeine
Healthline. (2017). The effects of caffeine on your body. Retrieved from https://www.healthline.com/health/caffeine-effects-on-body#7