The specialist named the optimal dose of caffeine per day.

Coffee can boost energy, affect endurance, and even improve mood, but if consumed improperly, it can disrupt sleep, deplete the adrenal glands, and lead to dehydration. Irina Lyalina, Acting Dean of the Faculty of Natural Sciences at the State University of Education, told Izvestia about this on July 15.

"Drinking coffee on an empty stomach, and even in the heat, is very harmful, nutritionists will say. But coffee has an exciting effect not only on the nervous system, but also on the cardiovascular system, which means that the blood moves faster and nourishes all organs. Caffeine increases the release of adrenaline, which causes our heart to start pounding faster. The blood runs faster through our tissues and organs, and we experience a burst of vivacity," the expert explained.

According to her, caffeine stimulates the production of cortisol and dopamine. This explains both the energy boost effect and the psychological dependence on the drink. Athletes often use caffeine in the training process to increase endurance and strength performance. However, if a person is overworked, excessive coffee consumption can lead to the opposite effect — depletion of the adrenal glands and the development of chronic fatigue.

Lyalina stressed that coffee before a workout is acceptable only for moderate and short-term loads. Otherwise, caffeine may not give the desired effect, but, on the contrary, harm the body.

In addition, coffee has an effect on digestion. The aroma and taste of the drink activate the outflow of bile, but the coffee itself thickens it due to its dehydrating effect. In this regard, the specialist recommends monitoring the level of water consumed with regular coffee consumption.

I'll pour you an invigorating drink: Russians are switching from coffee shops to coffee at home

The decline in sales of the drink is taking place, among other things, against the background of rising prices for raw materials

"Caffeine increases the synthesis of the pleasure hormone dopamine. That is why most people enjoy drinking a cup of coffee, and this is the main reason for dependence on this drink. If you drink a lot of coffee, this feeling disappears, but the addiction remains. The safest dose is no more than 300 mg of caffeine per day. This is equivalent to two cups of Americano coffee or espresso," Lyalina said.

The daily dose may vary depending on body weight. For example, a man weighing about 95 kg can afford up to four cups, while people with less weight should limit themselves to two.

Exceeding the permissible norm, especially in a state of fatigue, can lead to increased nervousness, impaired concentration, and impaired absorption of vitamins and minerals. Coffee also has a negative effect on sleep — it reduces its depth, causes insomnia and makes rest shallow.

The expert stressed that excessive coffee consumption is especially dangerous in hot weather. Due to the diuretic effect, the body loses fluid: coffee increases blood flow to the kidneys and disrupts sodium absorption. This leads to dehydration. In this regard, Lyalina recommends drinking coffee only in the morning and no more than two cups a day, and also avoiding the addition of milk and sugar — the first component can cause puffiness, and the second is harmful.

Lyalina told Izvestia on June 23 that less high—quality raw materials are often used in the production of instant coffee - leftover coffee beans. The unbalanced composition of raw materials for instant coffee worsens its taste, and manufacturers compensate for this with various additives, usually harmful to the body.