When you can drink coffee in the morning: scientists have found the answer

For many people, coffee is an integral part of their usual lifestyle: a daily ritual and a remedy for morning drowsiness. Recent research has shown that people who drink it at the beginning of the day have less chance of dying prematurely.

The Times publication found out how exactly the popular drink works and how best to consume it.

How coffee wakes us up

The key substance that provides the stimulating effect of coffee is caffeine - a molecule very similar to adenosine - a chemical that naturally forms in the brain.

Typically, adenosine accumulates throughout the day, binding to receptors that cause drowsiness. When we drink coffee, caffeine blocks these receptors, preventing adenosine from telling us that we are tired and need rest. As a result, we feel more alert. Numerous studies have confirmed that coffee improves reaction speed, alertness, and attention.

Can coffee increase happiness levels and relieve headaches

Caffeine can also affect dopamine levels, improving mood and motivation. Additionally, it causes mild constriction of blood vessels in the brain, which can help calm headaches and explains why caffeine is sometimes included in migraine medications.

It is also possible that the constriction of blood vessels leads to a slight increase in brain temperature, according to Dr. Nina Rzehorzek from Cambridge University.

Dr. Andrew Hulton, a sports science expert from the University of Surrey, says that caffeine can promote fat burning in the body.

"There is also research showing that you can increase your strength and power," he said. "This may be related to a reduced perception of effort. If you think you're working less and experiencing less pain, then you can push yourself harder."

The peak of this effect occurs approximately 45 minutes after taking the substance, but it can vary for different people.

When is the best time to drink coffee

Many of us reach for coffee right after getting out of bed, but there's a theory that it's better to wait.

Shortly before waking up, our body naturally produces cortisol - a stress hormone that helps us wake up. Coffee can increase cortisol levels, which can cause an unwanted surge in alertness and lead to increased tolerance and dependence on caffeine.

"Some data suggests that waiting a bit after waking up - maybe an hour - before the first cup of coffee can be beneficial," noted Rzehorzek.

"Coffee nap"

A "coffee nap" involves consuming a small amount of caffeine immediately before a short nap. Since caffeine starts working in about 20-45 minutes, the idea is that you get a double boost of energy: one from sleep and another from the effect of caffeine. Again, there isn't much research in this area, but Rzehorzek says it might be worth experimenting.

How long does coffee work

The half-life of caffeine is typically three to five hours, which means that if you drink coffee late in the evening or afternoon, it may still be in your system when you try to sleep. Doctors recommend limiting coffee consumption to the first half of the day.

However, your genetics play a very large role in how you respond to caffeine, including how it affects your sleep. For some people, the half-life can be ten hours, says Hulton.

The NHS recommends not exceeding 400 mg per day, but some people may experience tremors, rapid heartbeat, anxiety, and insomnia at lower doses. Pregnant women are advised not to exceed 200 mg of caffeine per day.

A study published in the European Journal of Preventive Cardiology in 2022 examined half a million UK adults and showed that those who drank between half and three cups of coffee a day had a lower risk of death from cardiovascular disease than those who did not consume coffee regularly.

Those who drank up to three cups also showed signs of a healthier heart: the left ventricle had thicker muscle walls, and the heart pumped more blood with each beat. Those who drank more than three cups had stronger hearts, but the risk of death did not decrease.

Another study, published in the International Journal of Stroke, showed that consuming up to three 250 ml cups of coffee per day does not negatively affect the risk of stroke, but consuming four or more cups increases this risk. Other studies link coffee to a healthier microbiome and reduced body fat levels.