Caffeine

The debate on caffeinated beverages is heated, perhaps even more controversial than other addictions considered 'normal'. For many, including doctors, discussing whether or not to drink coffee seems like a minor issue, a habit so ingrained and personal that it does not raise concerns.

Yet, market data speaks clearly: caffeine, along with alcohol, is one of the most consumed psychoactive substances in the world, and companies that produce caffeinated beverages are recording constantly growing profits.( 1 )

Why this popularity? And why do we have so many problems about the use of some psychoactive substances, excluding others like caffeine, often basing ourselves on preconceptions?

First of all, let's try to understand what we are talking about. Caffeine is a psychoactive alkaloid, a derivative of xanthine, which exerts its stimulating action through various mechanisms: it blocks adenosine receptors, inhibits the phosphodiesterase enzyme and probably also influences the translocation of intracellular calcium.

In simple words, caffeine stimulates the body by increasing levels of adrenaline and noradrenaline, activating the sympathetic nervous system and facilitating the transmission of dopamine and glutamate. It is, in all respects, a psychoactive substance, a real psychotropic drug with very specific effects: not only stimulating, but also enhancing pain treatment. In some neurodegenerative diseases, moreover, it could have a protective role, even if the risk/benefit ratio and the mechanism of action require further investigation. (2-3-4)

After this pharmacological premise, it is important to know that caffeine, and other very similar substances (methylxanthines), are present in various food and pharmaceutical forms: coffee, tea, cola drinks, energy drinks, cocoa, medicines, supplements and diet products.

Caffeine undoubtedly has the potential to induce dependence, as demonstrated by several clinical studies. However, there seems to be a certain reluctance to investigate the issue further, probably due to economic interests and the widespread idea that caffeine improves productivity and energy.(5-6)

Caffeine, like other psychoactive substances, is a food product whose consumption is incentivized by marketing precisely because it is capable of inducing dependence. The companies that produce cola-based drinks, for example, are among the most solid on the stock market, precisely because of the dependence that their products generate.

Caffeine, in fact, causes desire and, after a period of constant use, an abstinence syndrome, pushing both children and adults to regular consumption, just as happens with nicotine.(7-8)

Caffeine withdrawal syndrome is well documented in the literature and manifests with symptoms such as headache, insomnia, fatigue, difficulty concentrating and negative mood. This syndrome has also been observed in various animal species, not only in humans. (9-10-11)

It has been shown that taking small doses of caffeine is able to suppress these symptoms. In other words, if we feel agitated due to withdrawal, taking caffeine calms us because it interrupts the syndrome.( 11 )

However, caffeine has never been considered a real substance of abuse in the collective imagination. Nevertheless, its excessive and chronic use can have important pharmacological consequences.

Starting from the 70s, a syndrome called caffeinism has been described, characterized by manifestations affecting the central nervous system (anxiety, sleep disorders, mood alterations) and physical disorders (tachycardia, palpitations, muscle tension, respiratory alterations).

The lethal dose of caffeine is around 10 grams (about 70 cups of coffee), it is also true that more and more people, to cope with the need to perform more at work or to combat chronic fatigue, reach to consume high amounts, up to one gram per day.

Also in the case of caffeine, therefore, a moderate use is recommended, as happens with alcohol, food, smartphones and other substances or activities that can induce dependence.

The problem of addictions, however, always concerns four variables: the dependence potential of the substance, individual sensitivity, connection with the social environment and social and marketing pressures.

The vicious circle that leads to an excessive use of caffeine, or of stimulants in general, can be unpredictable and start even with apparently low doses.

It is fundamental, at this point, to talk about the relationship between caffeine and the brain. Caffeine can negatively influence some conditions of psychic distress. For example, the chronic use of caffeine as a stimulant can alter the sleep-wake rhythm, even if taken away from evening hours, since its half-life varies between 5 and 10 hours depending on the subject and some indirect effects can last even longer. Many sleep disorders, particularly those related to falling asleep, could be related to excessive use of caffeine. ( 12 )

It is now established that caffeine, while not being able to directly cause anxiety disorders, can worsen pre-existing ones, such as generalized anxiety and panic disorder. (13)

The effects of caffeine on cerebral circulation are still under study. It seems that this substance reduces blood flow to the brain, but further research is needed to fully understand the mechanism and consequences of this effect.

An important and complex aspect concerns the withdrawal syndrome, which is not always related to the amount of caffeine consumed. Some people, in fact, can experience withdrawal symptoms even after stopping the use of only three or four cups of coffee a day. (14)

Often, withdrawal symptoms manifest during the weekend or holidays, when the use of caffeine is reduced or interrupted in an attempt to relax. It is interesting to note how, in some cases, caffeine withdrawal syndrome can be mistakenly interpreted as difficulties in interpersonal or family relationships, when in reality it is simply an increase in irritability. (14)

In light of what has been said so far about coffee and caffeinated beverages, it is crucial to reflect carefully on our relationship with these stimulants, whose use is constantly increasing in the Western world.

When we are faced with substances that can induce dependence, it is essential to consider several factors:

• the substance's ability to induce dependence;

• individual sensitivity;

• the social and environmental context;

• social and marketing pressures.

Ref:

1. Caffeine Consumption- RM Gilbert; https://pubmed.ncbi.nlm.nih.gov/6396645/

2. The Medicinal Chemistry of Caffeine; https://pubmed.ncbi.nlm.nih.gov/34019396/

3. Caffeine as an analgesic adjuvant for acute pain in adults; https://pubmed.ncbi.nlm.nih.gov/25502052/

4. The neuroprotective effects of caffeine in neurodegenerative diseases; https://pmc.ncbi.nlm.nih.gov/articles/PMC6492672/

5. Behavior, Sleep, and Problematic Caffeine Consumption in a College-Aged Sample; https://www.liebertpub.com/doi/abs/10.1089/jcr.2012.0009

6. Development and initial validation of a caffeine craving questionnaire; https://pubmed.ncbi.nlm.nih.gov/18187535/

7. Physical dependence increases the relative reinforcing effects of caffeine versus placebo; https://pubmed.ncbi.nlm.nih.gov/9784073/

8. Caffeine reinforcement: the role of withdrawal; https://pubmed.ncbi.nlm.nih.gov/9160847/

9. Caffeine withdrawal; https://www.ncbi.nlm.nih.gov/books/NBK430790/

10. Characterization of individuals seeking treatment for caffeine dependence; https://pubmed.ncbi.nlm.nih.gov/22369218/

11. A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features; https://pubmed.ncbi.nlm.nih.gov/15448977/

12. Caffeine Use Disorder: A Comprehensive Review and Research Agenda; https://pmc.ncbi.nlm.nih.gov/articles/PMC3777290/

13. Effects of caffeine on anxiety and panic attacks in patients with panic disorder: A systematic review and meta-analysis; https://pubmed.ncbi.nlm.nih.gov/34871964/

14. Caffeine supplementation in the hospital: Potential role for the treatment of caffeine withdrawal; https://pubmed.ncbi.nlm.nih.gov/33932520/