Coffee and caffeine

# Coffee and caffeine metabolism Coffee is a stimulant and is made from roasted and ground coffee beans, the seeds from the fruit of the coffee plant, and hot water. The main active ingredient in coffee is caffeine, which has the following effects: - psychotropic (influences the human psyche) - stimulating (increases attention, concentration and drive) - positive inotropic (increases the contractility of the heart) - stimulating effect on intestinal peristalsis - weakly diuretic (stimulates urine production) Caffeine is not only a component of coffee, but also of tea, cola, mate, guarana, energy drinks and small amounts of cocoa. Caffeine is absorbed very quickly and almost completely via the gastrointestinal tract into the bloodstream. Practically all the caffeine is absorbed around 45 minutes after ingestion. The breakdown of caffeine varies from person to person, with age, gender, hormones, liver disease, obesity, smoking, diet and medication having an influence. In the liver, caffeine is mainly broken down by the enzyme cytochrome P450 1A2 (CYP1A2). The three most important metabolites in the breakdown of caffeine are paraxanthine, theobromine and theophylline. Genetic variations have an influence on the activity of the CYP1A2 enzyme. As a result, some people can metabolize caffeine faster than others. Age also plays a role, with younger people tending to metabolize caffeine faster than older people. # Examples of caffeine-rich foods: ## How does caffeine work? Caffeine is the world's most common psychoactive substance and an active ingredient in coffee, among other things. It is known that caffeine has an activating and stimulating effect on the body. Caffeine blocks adenosine receptors in the brain. Adenosine, a substance produced naturally in the body, normally inhibits nerve cell activity and has a calming and tiring effect. Blocking the receptors with caffeine has the opposite effect. It leads to a disinhibition, i.e. an activation of the nerve cells and the stimulating effect typical of caffeine. Furthermore, caffeine increases the release of dopamine and noradrenaline in the brain, which are associated with motivation, reward and attention. > ## Anxiety after caffeine? > > Studies have shown that caffeine can have an anxiety-inducing effect in people with a certain genetic make-up. However, the opposite effect has also been observed, namely an anxiety-relieving effect. Further studies are required for a definitive assessment. # What does genetics have to do with it? We are investigating two genes in coffee and caffeine metabolism: The CYP1A2 gene (cytochrome P450 1A2 gene) carries the blueprint for the cytochrome P450 1A2 enzyme in cells. Among other things, this enzyme metabolizes oestrogens and breaks down caffeine. People with a higher activity of CYP1A2 can break down and eliminate caffeine more quickly. This enables them to consume more caffeine without negative effects such as headaches, palpitations or discomfort. - Variant rs762551 of the CYP1A2 gene: Genotype C/C shows no activity of the enzyme, breaks down caffeine very slowly and is prone to undesirable side effects with higher amounts of caffeine. The C/A genotype shows reduced activity of the enzyme, breaks down caffeine slightly slower and can show undesirable side effects with increased consumption of caffeine. The A/A genotype shows a faster activity of the enzyme, can break down or eliminate caffeine more quickly and can consume higher doses of caffeine without negative effects. The ADORA2A gene (adenosine A2A receptor gene) carries the blueprint for the adenosine A2A receptor protein in the cells, which is involved in regulating the release of dopamine and glutamine, among other things. This makes the receptor a potential therapeutic target for the treatment of insomnia, pain, depression and Parkinson's disease. Caffeine partially blocks the receptors of these neurotransmitters. - Variant rs5751876 of the ADORA2A gene: The T/T genotype shows increased anxiety when caffeine is consumed. Genotypes C/C and T/C, on the other hand, show no increase in anxiety after caffeine consumption. - Variant rs2298383 of the ADORA2A gene: The C/C genotype shows increased anxiety when caffeine is consumed. Genotypes T/T and C/T, on the other hand, show no increase in anxiety after caffeine consumption.