What is caffeine?
Caffeine is a stimulant that can be found in coffee, tea, and cacao plants. By stimulating the brain and nervous system, caffeine prevents fatigue and keeps you alert. In 2737 B.C., tea was reportedly brewed for the first time. Ethiopian shepherds noticed that coffee gave their goats more energy many years later after they discovered it. In the late 1800s, caffeine-based soft drinks were introduced, followed by energy drinks.
How does it work?
Caffeine enters the bloodstream rapidly after consumption. The liver then processes it into compounds which can damage the organs. However, caffeine has the most effect on the brain. By blocking neurotransmitter adenosine, it prevents the brain from relaxing and making you feel tired. You feel sleepy after a long day due to the accumulation of adenosine in your body. Through adenosine receptors in the brain, caffeine helps keep you awake without activating them directly. Adenosine is blocked, resulting in reduced tiredness. Furthermore, it may increase blood levels of adrenaline and stimulate the release of norepinephrine and dopamine in the brain.
A further benefit of this combination is the ability to promote arousal, alertness, and focus in the brain. As a result of its effects on the brain, caffeine is often referred to as a psychoactive drug.
Nutrients are scarce without additives. K-Cup pods of Arabica coffee contain:
Fat: 0 grams
Protein: 0 grams
Carbohydrates: 0 grams
The same cup of coffee contains 120 milligrams of potassium and 4.98 milligrams of sodium.
Amounting to about four regular-sized cups of coffee, 400 milligrams of caffeine per day is the maximum recommended daily intake. Due to the difference in caffeine levels in each drink, this dosage recommendation will depend on what you’re drinking.
What foods and drinks contain caffeine?
The seeds, nuts, and leaves of certain plants contain caffeine naturally. These natural sources are harvested and processed to produce caffeinated foods and beverages.
Some of the most popular beverages have the following caffeine content per 8-ounce (240-mL) serving:
- 240-720 mg of espresso
- Energy drinks: 50 to 160 mg
- Coffee: 102 to 200 mg
- Yerba mate: 65 to 130 mg
- Brewed tea: 40 to 120 mg
- Decaffeinated coffee: 3 to 12 mg
- Cocoa beverage: 2 to 7 mg
- Soft drinks: 20 to 40 mg
- Chocolate milk: 2 to 7 mg
Caffeine can also be found in some foods. In one ounce (28 grams) of milk chocolate, there are 1–15 mg, whereas in one ounce of dark chocolate, there are 5–35 mg
Potential Health Benefits of Caffeine
The health benefits of caffeine are numerous, and it can be found in many foods. Researchers have discovered that caffeine can be beneficial to our health in several ways, including:
Boost Energy Levels
Most famously, caffeine helps people feel more energetic. Caffeine is a stimulant, and as a result improves moods, increases alertness levels, and reduces feelings of fatigue among its users.
Increased Metabolic Rate
Stimulants can boost your metabolism along with helping you become more alert. It has been shown that consuming a cup of coffee with its caffeine content can increase metabolic rate by 3-4%. Therefore, caffeine consumption increases your calorie burn slightly.
Improves Exercise Performance
You might be able to exercise more efficiently with the same reduction in fatigue. Research suggests that caffeine consumption before exercise can improve your athletic performance as well as reduce fatigue during the activity. You may even enjoy exercising more if caffeine makes it seem easier.
May protect against heart disease
Caffeine doesn’t cause heart disease despite what you might have heard.
Research shows that drinking between one and four cups of coffee a day (providing approximately 100–400 mg of caffeine) can reduce the risk of heart disease by 16–18%. Coffee or green tea consumed 2–4 times a day is associated with a 14–20% lower risk of stroke.
In some people, caffeine may raise blood pressure slightly. This effect, however, is usually small (3-4 millimeters of mercury) and fades with repeated consumption of coffee.
It may also protect against diabetes
Review research found that coffee drinkers were 29% less likely to develop type 2 diabetes. The risk of stroke is reduced by up to 30% for those who consume the most caffeine.
May improve mood and brain function
Adenosine, a molecule involved in brain signals, is blocked by caffeine. As a result, other signaling molecules, such as norepinephrine and dopamine, are increased. Mood and cognitive function are thought to benefit from this increase in brain messaging.
The consumption of 2 to 3 cups of coffee (containing 200 to 300 mg of caffeine) per day can reduce suicide risk by 45%.
The risk of developing Alzheimer’s and Parkinson’s may also be reduced by 28-60% if more than three cups of tea or coffee are consumed daily.
Coffee and tea also contain other bioactive compounds that may be beneficial (aside from caffeine).
Other health benefits of coffee
There are several other health benefits associated with coffee consumption:
- Protecting the liver
- Reduced cancer risk.
- Protecting the skin.
- MS risk is reduced (multiple sclerosis).
- Gut health.
- Gout prevention.
Potential Risks of Caffeine
You shouldn’t consume excessive amounts of caffeine, despite its health benefits. This can lead to negative effects when consumed in excess. Here are a few things to bear in mind:
As a habit-forming substance, caffeine is likely to become addictive. People with long-term caffeine consumption can experience withdrawal symptoms including headaches and irritability as a result of large amounts of caffeine. However, caffeine withdrawal can still be unpleasant, even though it is mild compared to many other withdrawal symptoms. Before you increase your caffeine consumption, think about the potential effects.
May Cause Headaches
Two reasons contribute to migraines and headaches caused by caffeine. First of all, if you have become addicted to caffeine, you may develop withdrawal symptoms like headaches if you don’t consume caffeine for one day. While you may experience headaches if you consume excessive amounts of caffeine. Caffeine helps some migraine sufferers with their symptoms, but others find that it triggers migraines.
There are a number of drugs that caffeine can interact with. Before adding caffeine to an individual’s regular diet, a doctor needs to be consulted if the individual is taking antidepressants, antipsychotics, antiarrhythmia medications, or psoriasis medications.
May Cause Anxiety
Caffeine can cause anxiety in some people. Caffeine can result in the release of a compound called kynurenine, which is linked to feelings of anxiety. Consuming less caffeine can reduce the effects of this compound.
What are the side effects from too much caffeine?
Caffeine up to 400mg a day isn’t harmful for the majority of people. It is possible to become ill from too much caffeine consumption, such as:
- Shakiness and restlessness
- Heart rate is fast
- There is a dependency, so to achieve the same results, you need more
Who should avoid or limit caffeine?
If you are experiencing any of the following symptoms, speak with your healthcare provider about caffeine and whether you should limit or avoid it:
- Your baby will be exposed to caffeine through your placenta if you are pregnant.
- Your baby consumes a small amount of caffeine when you’re nursing.
- Sleep disorders, such as insomnia, are common.
- You have migraines or another type of chronic headache.
- Have anxiety.
- Have ulcers or GERD.
- Your heartbeat is out of rhythm (arrhythmia).
- Blood pressure is high.
- Take certain medications or supplements, such as stimulants, certain antibiotics, asthma and heart medications. You should consult your health care provider about possible interactions between caffeine and any supplements or medications you are taking.
- You are a teen or child. You should drink less caffeine than adults. Children are more sensitive to caffeine’s effects than adults.
- Bioh G, et al. (2013). Survival of a highly toxic dose of caffeine. DOI:10.1136/bcr-2012-007454
- Caffeine chart. (2014). cspinet.org/eating-healthy/ingredients-of-concern/caffeine-chart
- Caffeine in pregnancy. (2015). marchofdimes.org/pregnancy/caffeine-in-pregnancy.aspx
- James J. (2011). Can consuming caffeine while breastfeeding harm your baby? An interview with Ruth Lawrence, PhD. DOI:10.1089/jcr.2011.1212
- Lexicon of alcohol and drug terms published by World Health Organization. (2013). who.int/substance_abuse/terminology/who_lexicon/en/
- Mayo Clinic Staff. (2017). Caffeine: How much is too much? mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20045678