Exactly what that cup of coffee does to your body from minute to minute (and yes, it DOES have a laxative effect)

For many of us, that morning coffee is an essential part of our daily ritual.

But have you ever wondered what exactly happens in your body after taking that first sip?

Here, MailOnline analyzes exactly that…

Have you ever wondered what exactly happens in your body after taking that first sip?

Within the first ten minutes…

The coffee starts flowing 10 minutes after the first sip.

Dr. Duane Mellor of the British Dietetic Association claims this reflects how quickly caffeine is absorbed into the bloodstream by parts of the digestive system.

“After drinking coffee, the caffeine will appear in the blood after about ten minutes,” he said.

‘Some can be absorbed through the mouth and stomach, but only in smaller amounts. Most of the absorption takes place in the first part of the intestines.’

Once the caffeine is absorbed into the coffee, you’ll feel that telltale energy boost.

What does caffeine contain and how much is it safe to drink?

  • Coffee, tea, cola and energy drinks contain large amounts of caffeine.
  • Caffeinated drinks are not suitable for toddlers and young children
  • Pregnant women should not consume more than 200 mg of caffeine per day, as high caffeine levels can cause babies to have low birth weight
  • The NHS suggests that more than 600mg of coffee a day (six cups) is too much and can lead to anxiety, insomnia and heart palpitations
  • One mug of instant coffee contains approximately 100 mg of caffeine
  • Energy drinks can contain 80mg of caffeine in a small 250ml can. This is the same as two cans of cola or a small cup of coffee
  • The NHS advises that tea and coffee are fine to drink as part of a balanced diet
  • But caffeinated drinks can cause the body to produce urine more quickly

However, this boost is a bit misleading. Caffeine does not actually provide energy.

Instead, it works by preventing your body from interacting with adenosine, a chemical that lurks inside us and makes us feel tired.

Caffeine works this way because its chemical structure is very similar to adenosine and fits like a key in a lock to the adenosine receptors in the body.

This prevents us from feeling tired, which naturally makes us more awake.

After 20 minutes…

Caffeine blocking the body’s adenosine receptors doesn’t just promote wakefulness, Dr. Mellor explains.

It is also thought to cause a rise in blood pressure within half an hour of drinking coffee – and the effects are still visible about four hours later.

This spike in blood pressure is caused by caffeine causing your blood vessels to constrict, causing your heart rate to increase.

Although temporary, the NHS warns that drinking more than four cups of coffee a day could increase your blood pressure in the long term.

After 45 minutes…

Caffeine’s effects on the body peak after 45 minutes, Dr. Mellor said.

The stimulating effect of coffee, the increase in your heart rate and the feeling of energy improves both concentration and memory.

But drinking too much coffee can have harmful consequences.

Too much caffeine won’t help you concentrate, but will make you feel jittery or anxious.

According to NHS guidelines, around 400mg of caffeine per day is safe for adults, the equivalent of four regular cups.

Pregnant women are advised to consume about half of that, while the recommended limit for teenagers is about 100 mg.

After 60 minutes…

After the stimulating effect of caffeine begins, you may notice an unwanted side effect.

Once caffeine appears in the blood, it will begin to have what experts call a diuretic effect, says Dr. Mellor.

This means that if you drink enough coffee, you will have to urinate more often than normal.

Just 10 minutes after drinking a cup of coffee, you may feel like you're waking up, an effect that can last about an hour

Just 10 minutes after drinking a cup of coffee, you may feel like you’re waking up, an effect that can last about an hour

When you drink coffee, the caffeine in the drink inhibits the production of antidiuretic hormone or ADH, which according to the NHS usually helps regulate the amount of water in your body.

This stops the kidneys from reabsorbing the water, causing you to urinate more.

But you’d have to drink a lot of it to avoid getting dehydrated.

Research shows that for coffee to affect your hydration levels, you should drink more than 500 mg of caffeine per day, or more than five cups.

A 2014 study by the school of sport and exercise at the University of Birmingham, found no evidence of dehydration with moderate daily coffee intake.

The NHS also says that drinking caffeine in moderation is a good way to stay hydrated, along with water, pumpkin and juice.

But coffee not only makes you pee more, you may also notice that it stimulates the urge to poop.

Studies have shown that coffee can activate contractions in your colon and internal muscles.

A 1998 study suggests that caffeine makes the colon 60 percent more active than water.

It is these contractions in the colon that push the contents towards the rectum.

After 90 minutes and beyond

The time it takes to metabolize caffeine varies from person to person.

But for most people, the stimulant effects begin to fade an hour or two after the first sip of coffee, as do the diuretic effects, according to Dr. Mellor.

This can cause feelings of fatigue, anxiety and poor concentration.

However, just because you feel a caffeine hit doesn’t mean the caffeine has completely left your system.

‘For most people, caffeine levels drop by about half after six hours as it is metabolized by the liver. So while the effects may seem to wear off after an hour or two, there will still be plenty of caffeine in your system.” he said.

This allows caffeine to linger in your body for up to twelve hours, according to researchers from the Sleep Foundation organization.

It adds that many sleep experts recommend avoiding caffeine at least eight hours before bedtime so it doesn’t disrupt your sleep. This means it’s best to avoid an afternoon brew.