Why Coffee Makes You Tired

The smell of coffee is what helps lots of people get out of bed in the morning. If you're one of those people who rush to the coffee machine as soon as they get to work, you're not alone. After water, it's one of the world's most popular drinks, with the highest coffee consumption in the Nordic countries.

Some people feel more alert and that they can perform better after drinking coffee. Others feel discomfort and become irritable. For lots of people, coffee causes problems with sleep. Coffee affects everyone differently, depending on how much they drink and when they drink it.

The caffeine in coffee is considered a drug, as it affects the body physiologically by stimulating the nervous system. It's addictive, and stopping drinking coffee results in withdrawal symptoms, although to a much lesser extent than alcohol, nicotine and hard drugs. Even so, there aren't many people who are willing to give up the coffee drug - it tastes good and makes us feel great.

How Caffeine Affects the Body

Caffeine is present in coffee, tea, cola, chocolate and energy drinks.

To understand how caffeine affects us, we have to take a step back and understand the adenosine molecule which is secreted by our cells. Adenosine makes us calm and tired, and helps us sleep after a long day. For example, it is secreted when we exert ourselves physically, which is why we feel tired after exercising. Caffeine binds to the receptors in the body which usually bind to adenosine. When these receptors can't bind to adenosine, we don't get as tired. Instead we perk up until the caffeine has been broken down. The brain is fooled by the caffeine into staying alert and if the caffeine isn't broken down by the time we go to bed, it can disrupt our sleep.

In the long run, the body adapts to the caffeine intake and develops more adenosine receptors. The effect of coffee is weakened, meaning you need to drink even more to feel alert. When you have been using coffee for a long period of time to feel alert and suppress adenosine, the risk is that you'll feel very tired. You won't experience the normal gradual build-up of adenosine in your body. Instead, once the liver has cleaned out all the caffeine, you'll get all the adenosine at once and may feel very tired. The fatigue you wanted to avoid by drinking coffee hits back twice as hard.

Is caffeine dangerous?

Too much caffeine can result in dizziness, heart palpitations, anxiety, stomach upset, vomiting and insomnia. When the body tries to counteract these side effects, the circadian rhythm and production of melatonin can be affected, which can negatively affect your sleep. Different people are affected in different ways. The effects of caffeine are dependent on the gender, age, weight and genetics of the person taking it. For example, the older you are the longer it takes longer for the body to break down caffeine. However, research has also shown that caffeine can reduce the severity of cardiovascular disease, along with reducing the risk of developing type-2 diabetes. According to scientists there are three groups of people who should watch their coffee intake: pregnant women, sufferers of anxiety and people with sleep disorders.

How Sleep Is Affected by How Much Coffee You Drink and at What Time You Drink It

Caffeine often increases the time it takes to fall asleep. How much and how late you can drink caffeine and still sleep well varies greatly from person to person. Caffeine blocks the adenosine which would otherwise make us tired, but the downside is it becomes harder to sleep. When you stop drinking coffee, you may feel tired, stressed, get headaches and have problems sleeping. Then you may feel you need to drink even more coffee, and it becomes a vicious cycle that makes your sleep even worse.

At What Time of Day Should You Avoid Coffee?

According to recommendations, you should stop drinking caffeine six hours before going to bed because it takes between three and five hours for the body to break down the caffeine. So the time of day you drink coffee definitely affects your sleep. If you drink a cup of coffee in the late afternoon, it's no surprise that you can't sleep a few hours later. It's not enough to just skip the last cup of coffee before bedtime. What's more, if you have drunk a lot of coffee throughout the day, then the body doesn't have time to break down the caffeine. If you want to sleep better, then it is worth trying to reduce your total caffeine intake during the day. You can start by gradually drinking fewer cups of coffee each day.

How Do I Know if It Contains Caffeine?

There should always be information on a product about its caffeine content, whether naturally or artificially added. Beverages, other than coffee or tea, containing more than 150 milligrams per litre are clearly labeled.

To understand how much caffeine a product actually contains, bear in mind that two to three cups of coffee (150 ml coffee per cup) can add up to 200 mg of caffeine.

Drinks With a High Caffeine Content

Espresso coffee contains the most caffeine, whereas the caffeine content in brewed or instant coffee is lower. There are, however, other drinks which contain caffeine apart from regular coffee and black tea. Most people know that energy drinks contain high amounts of caffeine and they shouldn't be used to just quench your thirst. Canned energy drinks often contain around 80 mg of caffeine per 250 ml, the same as one cup of instant coffee. Even green and white tea contain caffeine, but in slightly lower quantities as black tea. Cola drinks are high in caffeine and not suitable for children to drink in large quantities, because children are more sensitive to caffeine than adults. The Food Standards Agency advises that children and adolescents can have small doses (no more than 3 mg of caffeine per kg of body weight at one time, and a daily intake of up to 3 mg/kg). However, even one chocolate drink with high cacao content contains a significant amount of caffeine.

Other exciting alternatives to coffee which also contain caffeine include matcha latte (Japanese powdered green tea) and the South American drink yerba mate. Drinking these instead of coffee can help you reduce your caffeine intake gradually. However, don't drink them too late in the evening.

Decaffeinated coffee was launched as a suitable after-dinner drink for those who like the taste of coffee but want to be able to sleep well at night. Decaf contains around five percent of the caffeine of a regular cup of brewed coffee, so is not completely without caffeine as the name suggests.

Drink This Instead of Coffee

If you want to replace some of your daily cups of coffee with caffeine-free options, try these delicious alternative brews:

Tea infusions that don't contain caffeine, such as camomile, mint, ginger and rooibos (red tea).

There is also a whole new range of alternatives to your caffe latte. Why not try a golden latte, or golden milk, which contains turmeric and ginger? Or how about a beetroot latte, made from beetroot juice?

Many people feel that naturally caffeine-free chicory coffee (made from roasted chicory root) is a good alternative to regular coffee. You can even drink it with milk. You can also drink chai tea, or even lemon-infused water with honey, if you want to cut down on your coffee drinking.

Coconut water is good for reducing caffeine intake, while still giving you energy.

Tips: How to Drink Coffee and still sleep Well

There are lots of us who want to keep on enjoying our beloved coffee and still sleep well in the evening. Here's what you can do:

Drink coffee in the morning and before lunch, so that the caffeine is broken down by bedtime.

Avoid coffee (or drink only decaf) six hours before going to bed.

Swap the coffee you usually drink in the day for a caffeine-free drink.

Wait until 9:30 am before drinking your first cup. In the morning the body produces a lot of the hormone cortisol, which makes you feel alert, so you won't feel the caffeine kick until later.

Another idea is to drink coffee and then take a thirty minute nap. You wake up from the nap feeling rested, but also alert because of the coffee.

Plan to get your caffeine intake when you are usually the most tired. For most of us, this means after lunch - so drink your coffee half an hour before then, as it takes about thirty minutes for the caffeine to kick in.

Sources:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4169115/

https://www.ncbi.nlm.nih.gov/books/NBK223808/

https://sleepeducation.org/sleep-caffeine/

https://www.theguardian.com/food/2021/jul/06/caffeine-coffee-tea-invisible-addiction-is-it-time-to-give-up 

https://www.verywellfit.com/drink-coffee-to-boost-your-workouts-and-more-3121398

https://www.nhs.uk/live-well/eat-well/water-drinks-nutrition/

https://www.northumbria.nhs.uk/wp-content/uploads/2019/12/Sleep-apnoea-and-CPAP-treatment.pdf

https://www.independent.co.uk/news/science/under-the-microscope-how-does-caffeine-work-1993056.html

https://www.fastcompany.com/90240189/how-to-make-caffeine-more-effective-in-boosting-productivity

https://www.healthline.com/nutrition/best-time-to-drink-coffee

https://www.healthline.com/health/food-nutrition/alternatives-to-coffee

https://www.livsmedelsverket.se/livsmedel-och-innehall/oonskade-amnen/vaxtgifter/koffein2