Neuroscience reveals some little-known aspects of the habit of consuming coffee.
The story of coffee begins in the fourteenth century in Ethiopia, to where it was started stimulating properties attributed. From the Horn of Africa its use spread to Yemen in the 15th century and from there it spread to the rest of the Middle East and North Africa. It was the trade of Venetian ships with the Middle East that brought coffee to Europe, from where it was introduced to America (Cano-Mariana, Train and Cano, 2013).
Only in Spain 14,000 million cups of coffee are consumed per year, with the average weekday coffee consumption of 3.6 cups per day among those over 15 years of age. It should be added that 22 million people in Spain drink at least one coffee daily (Ramirez, 2016). These consumption patterns are similar in America and in the rest of Europe, with the Nordic countries leading the way in terms of per capita consumption.
Therefore, considering how established caffeinated beverages such as coffee are in the Western diet, the study of their effects in the short, medium and long term has become of great importance. The analyses and investigations have been carried out both on a psychological and physiological level.
What is coffee made of?
One of the main components of coffee, and one that gets its name from it, is caffeine. This substance, which we ingest in each cup, is a plant alkaloid that acts as an antagonist of adenosine receptors in the nervous system.Caffeine prevents the degradation of cyclic adenosine monophosphate by phosphodiesterases, which enhances postsynaptic neurotransmission in the sympathetic nervous system. Due to this, one of the main effects of caffeine in the body is, by increasing the intensity of transmission, causing activation in the body (Glade, 2010). Although caffeine is the best known, inside a cup of coffee we can find, among others, components such as vitamin B3, magnesium and potassium.
Beneficial effects of its consumption
According to the information provided by science throughout dozens of years of research, it appears that the positive effects of moderate and chronic coffee consumption far outweigh the possible harm it may cause. Other factors that increase alertness are involved in the consequences and affect of caffeine consumption, in addition to the substance itself, such as, for example, the consumer’s personality and the time of day (time of the circadian cycle).
Returning to its relationship with adenosine, in recent years studies have been carried out evaluating the neuroprotective role of caffeine in certain diseases . Adenosine itself plays an important role in the control of brain disorders, having inhibitory A1R receptors (which would function as an obstacle to neurodegeneration) and facilitating A2AR receptors (whose blocking would alleviate the long-term damage of various neurodegenerative conditions). Caffeine would come into play acting as an antagonist of the A2AR receptor, which would favour the phenomenon of synaptic plasticity and, like the rest of antagonists of this receptor, would act as a cognitive “normalizer”, preventing deterioration and reducing its advance .
Therefore, this could be a promising start in the study of adenosine A2AR receptor blockers, providing new and diverse therapeutic options for the treatment of the early stages of, for example, Alzheimer’s disease (Gomes et al., 2011).
The bitter side of caffeine
With regard to the harmful effects of caffeine, in Smith’s (2002) review of the subject, he states that these damages only appear under certain conditions. One of them would be when it is consumed by people with anxiety problems, whose activation level is already high.
In people not affected by this problem, the negative effects would occur when excessively high amounts are consumed. The intake of beverages such as coffee, in these situations, would cause an increase in anxiety and this would lead to, for example, tachycardia, difficulty sleeping, or even a worsening of fine motor control (Smith, 2002). When consumption exceeds approximately 300 mg per day, the motor system can be greatly activated, as well as altering the sleep-wake cycle in addition to a general increase in brain metabolism rates.
Although, like many other substances, inappropriate caffeine consumption can lead to a number of problems, there are reasons to be optimistic in this regard. Almost the entire group of consumers has a low to moderate intake (50-300 mg per day), these doses being the ones at which the aforementioned beneficial behavioral effects appear. Despite the fact that there are people who qualify coffee and, therefore, caffeine, as a socially accepted drug, the brain mechanisms that are affected when consuming this psych stimulant differ greatly from other substances of abuse such as cocaine , amphetamines, the Alcohol , nicotine and THC (Nehlig, 1999).
Why then does this consumption not reach harmful levels?
The area of the brain most related to drug dependence is considered in neuroscience as the pleasure area, that is, the nucleus acumens. This nucleus is divided both functionally and morphologically in a central zone and in the zone of the cortex. The mesolimbic dopamine system also participates in the reinforcement of addictive behaviour, which originates in the ventral tegmental area and ends in the nucleus acumens.
Sufficient amounts to feel the effects of drugs of abuse such as cocaine, alcohol and others selectively activate dopaminergic neurotransmission in the cortex of the nucleus acumens, which supports the extremely high addictive capacity of these substances. On the contrary, the consumption of caffeine necessary to activate its properties increases the release of dopamine only in the caudate nucleus without inducing any release in the nucleus acumens. This selective activation of the caudate nucleus would be related to the stimulatory properties of caffeine in psychomotor activity.
On the other hand, caffeine also stimulates the release of dopamine in the prefrontal cortex, which would be consistent with its psych stimulant properties and with the reinforcement of drinking behavior. For caffeine to increase the functional activity of the cortex of the nucleus acumens it should be consumed in an amount five times greater than the daily average. This high consumption would activate many other brain structures such as most of the limbic and thalamic regions and those related to the extrapyramidal motor system. This would explain the secondary effects of excessive consumption. As a conclusion to these data, Astrid (1998’1999) affirms that although caffeine has some criteria to be considered a drug of abuse, there is a very low risk of addiction.
Finally, taking into account the good capacity for self-regulation by the general population both in the amount to consume and at the time of day, the knowledge of the pros and cons of something as usual as having a cup of coffee, will favor even more responsible consumption. In light of the information that scientific research offers us, there does not seem to be a more powerful excuse to take a break and have a coffee in the company of friends, family or co-workers than to improve your own health. Everything is for the welfare.