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For many of us, that morning coffee is an essential part of our daily ritual.
But have you ever wondered what exactly happens inside your body after you take that first sip?
Here, MailOnline breaks down just that…
Have you ever wondered what exactly happens inside your body after you take that first sip?
In the first ten minutes…
The coffee begins to take effect just 10 minutes after the first sip.
Dr Duane Mellor of the British Dietetic Association says this reflects how quickly parts of the digestive system absorb caffeine into the bloodstream.
“After drinking coffee, caffeine will start to appear in the blood after about 10 minutes,” he said.
“Some can be absorbed through the mouth and stomach, but only in small quantities; most absorption occurs in the first part of the intestines.”
Once the caffeine from the coffee is absorbed, that’s when you feel that telltale boost of energy.
However, this momentum is a bit misleading. In reality, caffeine does not provide energy.
Instead, it works by preventing the body from interacting with adenosine, a chemical hiding inside us that makes us feel tired.
Caffeine works this way because its chemical structure closely resembles adenosine and fits like a key in a lock to the body’s adenosine receptors.
This prevents us from feeling tired, which naturally makes us more awake.
After 20 minutes…
Caffeine’s blocking of the body’s adenosine receptors not only promotes wakefulness, explains Dr. Mellor.
It is also thought to cause an increase in blood pressure half an hour after drinking coffee, and the effects can still be seen about four hours later.
This increase in blood pressure is caused by caffeine, which causes blood vessels to constrict and consequently increases heart rate.
Although temporary, the NHS warns that drinking more than four cups of coffee a day can increase blood pressure in the long term.
After 45 minutes…
The effects of caffeine on the body peak at 45 minutes, Dr. Mellor said.
The stimulating effect of coffee, increasing heart rate and feeling of energy, improves both concentration and memory.
But drinking too much coffee can have detrimental effects.
Too much caffeine, instead of helping you focus, makes you feel jittery or anxious.
NHS guidelines say around 400mg of caffeine a day is safe for adults, the equivalent of four regular cups.
Pregnant women are recommended to consume around half, while the recommended limit is around 100 mg for teenagers.
After 60 minutes…
Once the stimulating effect of caffeine kicks in, 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.
That means that if you drink enough coffee, you may need to urinate more than usual.
Just 10 minutes after drinking a cup of coffee you can start to feel it wake you up, an effect that can last for about an hour.
When you drink coffee, the caffeine in the drink inhibits the production of the antidiuretic hormone or ADH, which normally helps regulate the amount of water in the body, according to the NHS.
This prevents the kidneys from reabsorbing water and increases the amount of urine.
But you would need to drink a lot to dehydrate yourself.
Research shows that for coffee to have an impact on your hydration levels, you would need to drink more than 500 mg of caffeine per day, or more than five cups.
A 2014 study conducted by the University of Birmingham’s school of sport and exercise, 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 have to urinate more, you may also notice that it stimulates the urge to poop.
Studies have shown that coffee can activate contractions in the 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 into the rectum.
After 90 minutes and more
The time it takes for caffeine to be metabolized varies from person to person.
But, for most people, an hour or two after the first sip of coffee, the stimulant and diuretic effects begin to wear off, according to Dr. Mellor.
This can cause a feeling of tiredness, anxiety and lack of concentration.
However, just because you feel a caffeine crash doesn’t mean it has completely left your system.
“For most people, the amount of caffeine is reduced by about half after six hours as it is metabolized by the liver, so although the effects may seem to wear off after an hour or two, they still there will be a lot of caffeine in your system.” he said.
As a result, caffeine can remain in the body for up to 12 hours, according to researchers at the Sleep Foundation.
He adds that many sleep experts recommend avoiding caffeine at least eight hours before bed so it doesn’t interfere with sleep, which means it’s best to avoid an afternoon drink.
