The Side Effects of Caffeine: Is it Dangerous?

The Side Effects of Caffeine: Is it Dangerous?

With so many people turning to caffeine-free teas like the ones we sell, and many more choosing to drink decaffeinated tea and coffee, is there something wrong with the world’s favourite drug? Are we all addicted to something that is causing us harm?

Believe it or not, we’re actually pro-caffeine here on Shelgo Tea and recently published an article discussing the benefits of this popular stimulant (see Benefits of Caffeine). We firmly believe that when used responsibly, caffeine can be beneficial to your health. But as is the case with all drugs, it’s not side-effect free.

Why Caffeine May be Bad for You

For all the supposed health benefits of caffeine, there are also a number of concerns. Most of these occur either in caffeine-sensitive individuals, people on medication or with preexisting illnesses, or when caffeine is consumed in significant quantities.

Let’s break those down.

Caffeine Overdoses

It is generally thought that doses up to 400mg per day, providing it is not taken in one go, is safe and well tolerated in most healthy individuals. But as soon as you go beyond this limit, you run the risk of developing serious side effects.

Historically, deaths resulting from caffeine overdose are rare, with one study suggesting that the number of deaths from caffeine toxicity was roughly 1 per year between 1959 and 2010. A 2017 study found something similar. (1)

But there are two issues here. First, while the aforementioned study noted that most of these deaths were from powdered forms of caffeine, and that caffeinated beverages like tea and coffee were unlikely to cause overdose, it neglected to consider energy drinks, which can contain dangerous levels of the drug. Second, as several recent cases show, many deaths from excessive caffeine consumption lead to heart attacks, which is then seemingly attributed as the cause of death.

Nearly all of these are the result of energy drink consumption, either on their own or in combination with other caffeine products, and here are just a few of the more serious cases:

  • 2017, South Carolina, United States: A 16-year-old boy died at school after he is alleged to have consumed a Mountain Dew, a coffee, and an energy drink in the space of 40 minutes.
  • 2014, Ebonyi, Nigeria: A man died after drinking 8 cans of energy drink as a bet.
  • 2014, Rocky Point, Mexico: A 16-year-old boy from Arizona died from drinking too many energy drinks while on vacation in Mexico.
  • 2010, West Yorkshire, United Kingdom: A man is said to have suffered a haemorrhage and a series of mini strokes after consuming 25 cans of energy drink over the span of 6 hours. He spent years calling for the ban of these drinks after suffering continued effects.
  • 2007, New South Wales, Australia: A fit 28-year-old experienced a cardiac arrest after consuming 7 to 8 cans of an unnamed energy drink. (2) He recovered after extensive treatment.

Caffeine in People with Preexisting Illnesses

Caffeine is metabolised slowly in individuals with liver disease and it is not recommend in anyone suffering from epilepsy.

There are also many commonly prescribed medications that may cause interactions when consumed with caffeine. Many of these are minor, but in some cases it can significantly increase the risk of side effects, and in others it can stop the medication from working as it should.

Consumption of significant quantities of caffeine may also increase the risk of birth defects, which is why the World Health Organisation recommends that women restrict their intake during pregnancy. (3)

Caffeine Sensitivity

The effects and side effects of caffeine differ from person to person. Tolerance, health, history, and fitness can all play a role in deciding how you respond to this drug, but your genes may play the biggest role—you may simply be programmed to respond poorly to it.

Someone who is sensitive to caffeine may experience adverse side effects even with doses that someone else would consider therapeutic. If you experience any of the following side effects when consuming small to moderate amounts of caffeine (from a cup of green tea to a cup of medium-strength coffee) then you may have a sensitivity:

  • Nausea or vomiting
  • Chest Pains
  • Agitation
  • Headaches and migraines
  • Anxiousness
  • Dizziness
  • Rapid heartbeat

As mentioned above, caffeine sensitivity can be caused by many factors, but there is an enzyme in the liver that plays a significant role. This enzyme is called CYP1A2 and it helps to metabolise caffeine. The more of this you have, the less sensitive to the drug you will be. If you have very small amounts then you may be hypersensitive.

The concentration of this enzyme deceases with age and is also affected by oestrogen, which is why caffeine sensitivity is more common in women and why contraceptives and pregnancies can reduce the levels.

What are the Side Effects of Caffeine?

We listed some of the effects above. These typically only present in rare cases, when large amounts of the drug have been consumed, or when the person has a caffeine sensitivity.

However, someone who consumes a steady amount of caffeine over the course of the day is more likely to suffer from insomnia, and they may also struggle with irritability, fatigue, and difficulty concentrating when they go without caffeine for an extended period of time.

A caffeine overdose can trigger the following side effects. You may feel some of these during a low to moderate dose of caffeine, especially if you are sensitive, but with an overdose it is the severity that’s key. If you are worried that you have taken an overdose, seek medical assistance immediately:

  • Anxiety
  • Sweating
  • Dizziness
  • Vomiting
  • Rapid heartbeat
  • Heart palpitations
  • Nervousness/jitters
  • Cardiac arrest

Is Caffeine Dangerous?

The truth is that everything is dangerous in excess, even water, and even in moderation everything is dangerous to somebody. It all comes down to the method of consumption and the viability of more dangerous methods.

If you are drinking tea, then there’s a good chance that you’re staying within your limit, as you would need to drink close to 15 cups of green tea and 7 cups of strong black tea a day to surpass this. If you’re drinking coffee, it may only take 4 cups of strong coffee before you are at your limit. But even then, someone with a tolerance and someone who is otherwise fit and healthy is unlikely to experience any serious adverse effects (although they may be more irritable, anxious, and restless).

The only exception is if those amounts are being consumed in one sitting, and there lies the real issue. Because it is now very easy for a teenager—someone who may be less knowledgeable about the dangers of caffeine—to stop off at Starbucks or Costa and buy a large coffee before buying a couple cans of energy drink at their local store.

If they drink all of this quicker than their body can metabolise it, they will experience side effects. At the very least, they will feel their heart-rate increase, will feel anxious, and may suffer from digestive discomfort. At the worst, as the aforementioned cases prove, they may experience a cardiac arrest.

Caffeine can be perfectly safe and even healthy but not when it is consumed to excess.

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