Is coffee really the antidote to drowsiness?

AMERICA Coffee contains caffeine to help you feel refreshed and alert, but long-term use or too much will inhibit the adnosine receptor that causes sleepiness, causing the body to suffer from chronic sleep deprivation.

Professor Richard Alan Friedman, director of the Payne Whitney Psychiatric Clinic, said a 32-year-old patient fell asleep at a red light and was arrested by police on suspicion of using alcohol or drugs while driving. But in fact, the sleepiness came because the man was chronically sleep deprived. The pressure of work makes him try to sleep only 5 hours a day, instead of the recommended 7-9 hours. To keep himself alert, focused and energetic, he consumes 6 cups of coffee a day.

One cup of coffee (236 ml) provides about 100 mg of caffeine. Consuming 400-500 mg of caffeine per day is considered safe, while levels of 1,200 or more lead to poisoning, with manifestations of seizures or cardiac arrhythmias. As the patient above did not know that his brain was severely sleep deprived. The temporary feeling of wakefulness is just a trick of caffeine. In fact, no drug, including caffeine, can effectively reverse sleep deprivation.

In the brain there is a substance called adenosine that plays a key role in the regulation of sleep. The amount of adenosine is lowest in the morning when we just wake up, and gradually increases during the day to create pressure that makes the body need to sleep at night. Adenosine is removed from the brain during sleep keeping us awake when we wake up. Caffeine is a powerful antagonist of adenosine receptors, blocking the sedative effect, making you feel euphoric and alert.

The problem is that when you cut your sleep short, adenosine is not completely removed from the brain. The more sleep deprived, the more adenosine levels are left in the brain, creating a feeling of fatigue, persistent sleepiness and impaired cognitive function.

The brain tries to deal with this by increasing the number of adenosine receptors to make you feel tired and go to sleep. However, instead of going to bed, you drink more coffee without knowing that only getting enough sleep can prevent adenosine from increasing.

Lack of sleep not only makes you tired, it also weakens the brain's ability to consolidate memory. Sleep deprivation can also cause irritability, lack of emotional control in the average person, and worsen depression and anxiety disorders in people with mental health problems.

Black coffee contains caffeine to help you stay awake. Photo: Freepik

How coffee does not affect sleep?

According to research by the US Food and Drug Administration (FDA), the half-life (the time it takes the body to metabolize 50% of the caffeine consumed) usually ranges from 4-6 hours. An adult should drink no more than 4-5 cups of coffee a day. For those who are sensitive to coffee, this number may be less and should consult a doctor if necessary.

Besides, drinking coffee all day will make it difficult for you to sleep, even disabling sedatives. The best way is to drink coffee in the morning and avoid using it after lunch. Some people have a genetic problem of slow caffeine metabolism, can lose sleep even when drinking coffee early in the morning, so they should switch to tea.

It is a fact that you cannot use caffeine to fight sleepiness for the rest of your life because adenosine residues are increasing in the brain, which will make you "crash".

"When that happens, don't panic and rush to take sleeping pills, let your brain rest naturally," Professor Friedman advises.