What would a day be without a small black coffee in the morning? Each coffee lover will certainly appreciate the taste and aroma of freshly ground coffee. However, not everyone knows what effect this black beverage can have on the body. I will try to dispel 5 the most common myths about coffee that I‘ve met.

       About the addictive influence of caffeine, have been made many theories. Some of them even suggest that influence of caffeine on stimulation of the nervous system is not significantly different from the one caused by drugs. While caffeine is still a psychoactive substance, mechanism of it‘s impact on the central nervous system is not the same as mechanism of other stimulants, including alcohol and nicotine.

      Studies have shown that caffeine does not stimulate secretion of dopamine by the „reward center” present in brain, as it‘s observed with other stimulants. „Yeah, but what if I drink a few cups of coffee per day, and I‘m not as well energized as I was while drinking only one?” This happens due to the fact that the body actually adapts to a certain dose of caffeine, but it‘s related to reduction of adenosine receptor‘s sensitivity to caffeine, as it‘s regularly consumed.

      Caffeine can actually induce a kind of „withdrawal syndrome”, also called a discontinuation syndrome. It usually manifests with a feeling of tiredness, deterioration of mood and concentration, or even a headache. However, your body quickly adjusts to doses of caffeine, and the same deterioration of well-being usually lasts no more than few days.

       It‘s true that caffeine increases diuresis to some extent. However, none of the studies indicate it can cause dehydration. Some changes in the body‘s water content are observed after consumption of caffeine, but this effect lasts shortly after it‘s consumption, or affect people who had not consumed it regularly before. Similar to the effect of caffeine on the CNS, diuretic effect loses it‘s strength with regular caffeine intake.

      Slight decrease in water content in the body (on average 0,2% BM; clinical dehydration is observed with loss of 1-3% of body weight) does not cause clinical dehydration. What‘s more, if we consume caffeine with coffee, we also supply a certain amount of water with it. Caffeine therefore does not cause dehydration, but keep in mind that large doses of caffeine can have much bigger diuretic effect, actually causing dehydration. Accordingly, I wouldn‘t advise to drink 6 or more cups of coffee each day.

       Indeed, caffeine can cause an increase in blood pressure, and also, similarly to it‘s effect on diuresis, this effect is short-lived, and occurs mainly in people who had not consumed caffeine regularly before. What‘s more, as in the case of CNS stimulation, the body adapts to the regularly consumed dose, and there is no significant increase in blood pressure while drinking coffee regularly. Researches show that regular drinking filtered coffee (for example, from a pressure coffee maker), especially the green one, may even cause a drop in blood pressure in people with hypertension.

       For sure, coffee contains polyphenoles, such as tannins, which bind certain substances, including calcium, forming insoluble complexes with them. It weakens their absorption and increases the risk of their deficiency. In the case of hypocalcemia, body replenishes calcium deficiency by taking it from the bones, resulting in a reduced bone density, which can cause fractures. Adequate calcium supply is important not only for maintaining the proper structure of bones and teeth, but also for correct heart function and proper blood coagulation.

      Fortunately, coffee does not cause significant calcium deficiencies and it‘s easy to supplement them, even adding a bit of milk to the coffee or increasing the supply of calcium in the diet. It‘s also worth taking care of the proper intake of vitamin D3, which is responsible for the proper absorption of calcium.

      In fact, freeze-dried instant coffee of the highest quality does not show a particularly negative effect on health. The situation is different with instant products like „2 in 1”, which in addition to coffee, may also contain dyes, preservatives, and sweeteners. Instant coffee can be even healthier than regular coffee, especially the long-brewed one, for example Turkish coffee, when during a longer extraction, much more harmful compounds such as diterpens are transferred to the brew. The healthiest choice will still be filtered coffee, and for me personally, instant coffee will never be equal to freshly ground brewered coffee in terms of taste and aroma.