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Is drinking coffee dehydrating?

Even if you are not used to drinking coffee during the day, you end up taking caffeine in other foods. This is because caffeine is the most consumed psychoactive substance on the planet, also found in teas, soft drinks and even chocolate.

Coffee drains fluid from the body. Since drinking coffee, lovers of the hot beverage have had to grapple with this prejudice. Yet contrary to popular belief, this is just a food myth.

Every morning most people have a cup of coffee on the table. Yet athletes often refrain from taking caffeine because water is supposed to be removed from the body. However, coffee does not drain any liquid from the body. It also has other positive side effects.

The myth that coffee dehydrates the body has long been widespread and supported by science. Coffee drains, increases blood pressure and damages the cardiovascular system. It was said for a long time. Yet in recent studies it was found that one or the other cup does no harm.

In most countries, there are no regulations on its consumption, but some people blame the chemical compound for certain undesirable effects, such as dehydration.

What comes in must leave

cup of coffee, books and eyeglass

The scientific basis for stating that coffee causes dehydration comes from a study carried out in 1928, which registered an increase in the amount of urine expelled by people who consumed drinks with caffeine.

According to Lawrence Armstrong, a professor in the Department of Kinesiology at the University of Connecticut and director of the Human Performance Laboratory, the result spread quickly, and from there the fame that coffee dehydrates has settled over time.

In the end, our body is a little more complex than that. Armstrong recalls that we can use water itself as a reference. If we take more than we are used to, there will also be an increase in the amount of urine, which is not why it dehydrates us.

In an interview with Live Science, he points out that "the truth about the matter is that a small increase in the amount of urine expelled does not mean that the body is dehydrated".

To obtain more accurate data and to demystify caffeine consumption, Armstrong and a group of researchers experimented in 2005. On that occasion, they determined what 59 healthy men would eat for 11 days, regulating the amount of caffeine each ingested through capsules, 2 times a day.

Unlike the study conducted at the beginning of the last century, they used 20 different biomarkers to determine the degree of dehydration in the participants. Previous work has analyzed only the effects of occasional caffeine consumption; Armstrong's research was the first to look at the consequences over an entire day.

The results showed that the indicators evaluated, including the amount of urine, remained similar in all research groups. That is, some participants consumed placebo pills instead of caffeine and, even so, presented measurements of dehydration similar to those of those who consumed the substance. The same happened among those who consumed small and large doses of caffeine.

Far beyond dehydration

Good coffee is appreciated worldwide, but many believe that caffeine is responsible for many health problems, in addition to dehydration. Among the effects pointed out is the development of cancer or the influence on the growth of children, who would not develop correctly due to drinking.

For Armstrong, all this is just an urban legend, because if it were true, we would have emergencies in hospitals full of patients affected by coffee consumption. If the substance had such pronounced negative effects, they would certainly have been identified.

As with any food, excessive caffeine consumption can cause death. The lethal dose, according to Armstrong, would be 10,000 milligrams over 24 hours, but a 200 ml cup contains only 95 milligrams of the substance. So, for you to achieve the feat of drinking the lethal dose of caffeine through drinking, you would need to drink only 20 liters of coffee.

End of a myth

coffee and books

If you look at the water balance in your body, it doesn't matter whether you drink a glass of water or as much coffee. The only difference is that coffee stimulates the kidney's filtering function. This means that you have to leave earlier after enjoying a cup of coffee than after a glass of water. Kidney stimulation does not last long. And the amount that you excrete is almost the same for both liquids.

This is borne out by the following figures: whoever drinks coffee excretes an average of 84 percent of the liquid absorbed within 24 hours. In the case of water, the percentage is only slightly lower at 81 percent. So there can be no question of excessive drainage.

Coffee also does not disturb the electrolyte balance, as is often assumed. Therefore, you can safely ignore warnings that you should avoid coffee before a workout. Only in exceptional cases, such as when you are very thirsty, it is better not to drink coffee. Because then a cup can raise blood pressure significantly. If you are thirsty, a glass of water is always preferable.

Contrary to what many people say, coffee has already proven itself to be a beverage that has several benefits in its consumption. The antioxidants present in the grains can protect us against liver cancer, type 2 diabetes, lower blood pressure and even fight dementia and depression.

Drink for athletes

Coffee even has specific positive properties, especially for athletes. Because the caffeine blocks the messenger adenosine, which makes you tired. Besides, caffeine increases the release of the happiness hormones adrenaline and dopamine. The ability to concentrate is also improved.

A new study at the Royal Melbourne Institute of Technology in Bundoora (Australia) has even shown that caffeine helps to fill glycogen stores faster after a strenuous training session.

But that doesn't mean that you can pour liters of coffee into yourself. As with all foods, it means measuring 5 cups of coffee a day is safe for the water balance. yet it shouldn't be more. If you drink more, your ability to concentrate and think lessens. You become more restless, which complicates complicated tasks.

Further research is still needed to determine possible harmful effects on children and adolescents, when they consume alcohol excessively or in conjunction with alcohol and other drugs. In general, there is no problem drinking a cup of coffee a day, as it will not dehydrate you and can be part of a healthy routine


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