Caffeine is a natural substance that can stimulate the central nervous system, making those consuming it more alert and less tired.

As is well known, the primary source of caffeine is coffee. It is essential to know how much coffee we can consume daily and understand whether excess caffeine may have side effects.

Too Much Caffeine: The Side Effects

In addition to coffee, caffeine intake comes from cola drinks and tea. Usually, the stimulating effect occurs after about 15 to 30 minutes. It can last a few hours, taking about 2-4 hours to clear, depending on parameters such as body weight, liver health, age, and gender.

Side effects can be short-term and long-term, and it is essential to know them to avoid excessive caffeine intake.

Caffeine is not recommended for those suffering from peptic ulcer or gastritis as it increases the level of acidity in the stomach. Because it can facilitate intestinal motility, caffeine should also be limited for those who have colitis. Those who suffer from constipation, on the other hand, may find it helpful.

Precisely because of its stimulant activity, caffeine could cause central nervous system disorders, from sleep disturbances to anxiety, difficulty falling asleep, and nocturnal awakenings. If combined with poor lifestyles, smoking, or stress, its adverse effects may be amplified.

Coffee would be recommended only for those in good health. It is not recommended, however, for those who suffer from anxiety and turn to coffee for mental and physical support to cope with daily life. Drinking much coffee can increase the heart rate, resulting in tachycardia, one of the symptoms that most worry anxious individuals and contributes to worsening the situation. It is better to moderate coffee consumption in times of intense stress, only having one coffee at breakfast.

Coffee can also interfere with the absorption of iron and calcium. People with osteoporosis, women with sideropenic anemia, or menopausal women should, therefore, moderate coffee consumption to a maximum of two cups daily. For the same reason, it would be best to decrease intake during pregnancy to promote proper absorption of nutrients.

How Much Caffeine is in Coffee?

On average, the caffeine content in coffee is:

  • Espresso (1 oz): 60-120 mg
  • Moka coffee (1.2-1.7 oz): 60-120 mg
  • American coffee (3.4 oz): 95-125 mg

According to the European Food Safety Authority (EFSA), adults can safely consume up to 200 mg of caffeine. However, if consumed shortly before bedtime, single doses of about 100 mg can affect sleep quality. Therefore, it is advisable to consume caffeine in the early hours of the day, avoiding going beyond 3 p.m.

Starting the day with a hearty breakfast can be an excellent way to start with the right energy. For example, you could eat yogurt combined with whole-grain cereals and dried fruits such as almonds and walnuts, which are excellent sources of magnesium and can provide the right amount of energy.

Vitamin C, found in many fruits such as citrus fruits, strawberries, currants, and kiwi, is a significant boost to our immune system. However, it is also essential for synthesizing our adrenal hormones (cortisol). An orange juice could be an excellent alternative to coffee as a mid-morning energy snack.

Differences between Caffeine and Theine

Although caffeine and theine have the same chemical composition, there are several differences between them. 

Here are a few:

  • The concentration and amount of the active ingredient in tea are lower than in coffee.
  • Tea contains a high amount of polyphenols, which are substances with antioxidant properties that slow down the absorption of theine. This causes a slower but more prolonged stimulating effect.
  • Theanine, a natural amino acid found mainly in green and black tea, can stimulate GABA (gamma-aminobutyric acid), an inhibitory-acting neurotransmitter that promotes relaxation.
  • The presence of polyphenols and theanine in tea can reduce the excitatory effects on the cardiovascular system, limiting tachycardia and maintaining stimulation of the cerebral nervous system. As a result, theine’s effect is mitigated, and it can improve the ability to concentrate without acting as an excitant like coffee.