Alarm clock and coffee. A research on the beneficial effects of caffeine

A new day of self-respect can only begin with the morning “ritual” of … a cup of coffee. A few sips and the dark drink begin to make its beneficial effects noticeable and prepare us to face the world that awaits us. The important thing is not to overdo the doses.

In fact, caffeine intake is extremely widespread in the world (about 80% of the world’s population), through the consumption of coffee, tea, carbonated and energy drinks, or by eating chocolate. For this reason, researchers have for some time now become interested in the effects that the consumption of this psychoactive substance (a natural alkaloid) can have on brain function and, more generally, on health.

For example, in 2019, a meta-analysis study (published in the European Journal of Epidemiology) of 40 studies – for a total of almost four million people involved – showed that drinking an average of 3 cups of coffee a day reduces the risk of death, including cardiovascular disease. and cancer. More recently (2021), an article in “Scientific Reports” showed how a single cup of coffee, half an hour after its intake, could improve volunteers’ performance in cognitive tests, increasing their brain’s functional connectivity.

In fact, almost all caffeine studies conducted to date have focused on its immediate effects (usually within twenty-four hours of taking it). On the contrary, few researchers have been interested in the long-term benefits of daily consumption of this substance, and no one has ever studied the molecular mechanisms that, within nerve cells, determine its effects.

“Immediately after drinking coffee,” explains David Blum, a neuroscientist at the National Institute of Health and Medical Research at the University of Lille in France, “we feel more ‘awake’, that is, our attention threshold increases; but a moderate and habitual consumption of Caffeine, say two to four cups of American coffee a day, has a much more significant long-term effect: it alters the brain at the level of cellular activity. ”How? This is explained in detail by a recent study (published in the Journal). of Clinical Investigation “) conducted by a research group coordinated by Blum himself.

In practice, every day for two weeks, the researchers gave mice water with caffeine (in amounts equivalent to moderate consumption for humans) to drink; then Blum and colleagues performed an epigenetic analysis, ie related to the regulation of the transcription of genes, metabolism, RNA and proteins within the nerve cells in the hippocampus (the brain area where memory consolidation and learning).

“In the dormant brain,” explains Blum, “caffeine reduces the synthesis of proteins involved in metabolism in non-neuronal cells, while in neurons it increases the production of proteins linked to their activation and synaptic activity. Well, many of the latter remain overexpressed even after two weeks of “detoxification”, ie without having taken caffeine, which proves that a moderate but prolonged consumption of caffeine exerts a lasting effect on nerve cells.

The experiment was not limited to investigating the effects of this substance on the dormant brain, but wanted to observe what happened in the active phase of learning, for example when mice learned to orient themselves in a water maze. Results? The “caffeine-dependent” animals were able to find their way out faster and better, and at the molecular level, in contrast to what happened at rest, there was an increase in the synthesis of proteins linked to metabolic processes in non-neuronal cells (astrocytes, oligodendrocytes and microglial cells ). “There seems to be a link – Blum adds – between the metabolism of non-neuronal cells and the activity of neurons; it is as if the metabolic” pause “of the non-neuronal cells when the brain is at rest serves to prepare the circuits in anticipation of the moment when their activation is required, for example when learning to perform a new task “.

Therefore, caffeine can not only increase our level of attention, but it also seems to benefit complex cognitive skills such as learning. A truth, this, already highlighted by previous studies, although there was no molecular evidence. For example, it was already known that bees after taking caffeine remember smells better; a massive administration of the substance increases the mnemonic performance of the mice; in humans, drinking coffee improves the performance of discrimination tests. It was also already known that a habitual consumption of caffeine counteracts the cognitive impairment that is naturally observed in old age but also in pathological conditions such as Alzheimer’s or other neuropsychiatric diseases. “Caffeine – Blum concludes – slows down memory loss in the elderly and in people with dementia and Alzheimer’s and this is probably done through the” normalization “of synaptic activity, as shown by our research. But to prove it, other studies will need to be performed.”

And now, comforted by science, we can enjoy our cup of coffee with greater peace of mind!

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