Tea and coffee are two incredible beverages with a lot of caffeine content.
Several studies reveal that caffeine is safe for most people especially when consumed in low-to-moderate amounts (4).
But, high intake of caffeine may have some unpleasant side effects.
That is the whole essence of this article, to highlight 9 possible side effects of excessive caffeine.
1. Excessive caffeine Promotes Insomnia
Most people choose to take caffeine in order to stay awake.
But too much of it can make it difficult for you to get enough restorative sleep.
Nevertheless, a low or moderate amount of caffeine does not seem to affect sleep so much in people who are considered good sleepers or those with self-reported insomnia (10).
In most cases, you may not realize that excessive caffeine is interfering with your sleep, especially if you estimate the amount you are taking in.
As mentioned earlier, tea and coffee are the two most concentrated source of caffeine, although it can also be found in cocoa, soda, energy drink and several types of medication.
It is worthy of note, that, the amount of caffeine you consume without affecting your sleep quality will depend on your genetic makeup and other factors.
Also, note that caffeine consumed later in the day may interfere with your sleep because its effects may take several hours to wear off.
Studies show that caffeine can remain in your system for an average of five hours, but the time period may range from one and a half hours to nine hours, depending on the individual (11).
2. Excessive caffeine May Encourage Anxiety
Another effect of caffeine is that it increases alertness.
It functions by inhibiting the effects of adenosine, a brain chemical that makes you feel tired excessively.
On the other hand, it triggers the release of adrenaline, a hormone associated with increased energy (12).
However, when you consume a high dose of caffeine, it may become too pronounced leading to anxiety and nervousness.
In fact, the American Psychiatric Association listed caffeine-induced disorder as one of the four caffeine-related syndromes in the Diagnostic and Statistical Manual of Mental Disorders.
Consuming caffeine in the excess of 1,000 mg or more per day may lead to nervousness, jitteriness and similar symptoms to most people, whereas a moderate intake may lead to similar effects in sensitive individuals (13, 14).
If you feel nervous or jittery after consuming caffeine, it might be a good idea to check the level of your caffeine intake and moderate or cut back totally.
3. Risk of Muscle Breakdown
Excessive caffeine could lead to muscle breakdown and with a resulting effect being Rhabdomyolysis.
This is a serious health condition whereby damaged muscle fibers enter the blood stream, leading to kidney failure and other complications.
Some common causes of rhabdomyolysis include drug abuse, muscle strain, infection, trauma, and bites from poisonous snakes and insects.
Also, consumption of high dosage of caffeine within a short period of time, especially for someone whose body isn’t used to it could expose one to this effect.
To minimize this risk factor of rhabdomyolysis, limit your intake to about 250mg of caffeine daily unless you are used to consuming more.
4. Risk of Addiction
Caffeine has numerous health benefits, but we can’t deny the fact that it may become habit-forming.
A neuroscience and behavioral review suggest that although it triggers certain brain chemical similar to the way amphetamines and cocaine do, it, however, does not cause classic addiction the way these two drugs do (20).
It went further to conclude thus; it may lead to psychological or physical dependency, especially at high dosages.
Also, the frequency of caffeine intake seems to play a vital role in dependency.
Furthermore, even though these compounds does not seem to cause classic addiction, the fact is, if you regularly consume a lot of coffee or other caffeinated beverages, there is a good chance you may become dependent on its side effects.
5. Excessive caffeine May Cause Digestive Issues
Many people experience bowel motility after a cup of coffee in the morning.
The laxative effect of coffee has been attributed to the release of GI hormone gastrin which stimulates activity in the colon.
One way by which caffeine stimulate bowel movements is by increasing peristalsis; the contractions that move food through your digestive tract (23).
Given this effect, it’s not surprising that large doses of caffeine may lead to loose stools or even diarrhea in some people.
Many years ago, it was believed that coffee causes stomach ulcer, however, studies didn’t find any link between the two (24).
Since coffee has some potential effect on digestive health, you may want to cut back on excessive intake.
6. High Blood Pressure
Caffeine doesn’t seem to increase the risk of heart disease or stroke in most people.
High blood pressure is a major risk factor for heart attack and stroke because it has potentials of damaging arteries and restricting blood flow to your heart and brain.
The good news is that its effect on blood pressure seems to be temporary. But, it seems to have the highest impact in people who aren’t used to consuming a high amount of it.
On that note, it is important to pay close attention to the dosage and timing of caffeine especially if you are hypertensive.
7. Rapid Heart Rate
Excessive caffeine has stimulatory effects and may cause your heart to beat faster.
Not only that, it may also alter heartbeat rhythm, called atrial fibrillation, a condition that has been reported in young people who consume high doses of caffeinated energy drinks (33).
If you notice any changes in your heart rate or rhythm after drinking caffeinated beverages, your may consider decreasing your intake
8. Frequent Urination and Urgency
Frequent urination and urgency is a common side effect of high intake of caffeine due to their stimulatory effects on the bladder.
You may have the urge of urinating frequently especially when you drink coffee or tea.
A 2011 study of 12 young to middle-aged people with overactive bladder who consumed 2 mg of caffeine per pound of body weight shows a significant increase in urinary frequency and urgency (35).
Additionally, high intake of caffeine may increase the likelihood of developing incontinence in people with healthy bladders.
If you feel urgent urge after consuming a caffeinated beverage, it may be a good idea to cut back on your intake.
9. Excessive caffeine May Cause Fatigue
Tea, coffee and other caffeinated drinks are known to boost energy levels.
But, they can also produce unpleasant side effects by leading to rebound fatigue after the caffeine is flushed out of your system.
A 2011 review suggests that although caffeinated energy drinks increase alertness and improve mood for several hours, participants were often more tired than usual the following day (37).
So if you drink caffeine throughout the day, it may affect your ability to sleep in then night.
Caffeine has numerous health benefits, especially when consumed in light-to-moderate amount.
However, excessive intake may lead to unpleasant side effects that may interfere with your day-to-day activity.
It is also worthy of note that, response varies from person to person. And to benefits from caffeine without side effects, you need to assess yourself.