Coffee is a key part of many people’s diets, but how long does the caffeine last in the body?
It takes around 45 minutes for 99% of the drink’s caffeine to be absorbed through the body. For most people, the half-life of caffeine (which is the time taken for the body to eliminate one-half of the caffeine) can be from 4 to 6 hours.
But all of the above can vary depending on the person’s age, weight and medical conditions.
Let’s break it down.
What is caffeine?
According to Better Health, caffeine is a naturally occurring compound found in the leaves and fruits of certain plaints. It’s found in coffee, tea, soft drinks and energy drinks.
Caffeine is a stimulant, which increases activity in the brain and central nervous system. In small doses, it can make you feel refreshed and focused. In large doses, you are likely to feel anxious and have difficulty sleeping.
How does caffeine affect the body?
Caffeine increases the circulation of chemicals such as cortisol and adrenaline in the body and the short term effects can include increased breathing, heart rate, mental alertness and physical energy. Depending on the person, these effects can last up to 12 hours.
Excessive intake of caffeine can affect the body in different ways including a rise in body temperature, dehydration, dizziness, headaches, rapid heartbeat, restlessness, anxiety and trembling hands.
It also acts as a diuretic (increases the rate of bodily urine excretion).
Free Dieting provides the below diagram of the affects.
How long does caffeine last in your body?
The body starts processing caffeine as soon as it is ingested, and Healthline states that you may start experiencing the effects of caffeine right after consuming it and the effects will continue to last for as long as the caffeine remains in your body.
According to the American Academy of Sleep Medicine, caffeine’s half-life is up to 5 hours. So for example, if you’ve consumed 10 mg of caffeine, after 5 hours you’ll still have 5 mg of caffeine in your body.
The effects we discussed above reach peak levels within 30 to 60 minutes, but the other half of caffeine that you consume can last longer than 5 hours. For those more sensitive to caffeine, you may feel the symptoms for several hours or even a few days after consumption, which is why the academy doesn’t recommend consuming caffeine at least six hours before you sleep.
Which areas of the body does caffeine affect?
Caffeine is absorbed in the body very quickly and enters the bloodstream through the mouth, oesophagus, stomach and small intestine. While it doesn’t accumulate in the bloodstream nor is it stored in the body, it does affect different parts if the body.
Heart: The stimulant effect of caffeine speeds up the heart rate. For most people who drink caffeine in moderation, this isn’t necessarily harmful but it can increase anxiety and people experiencing panic reactions often worry they are having a heart attack. In higher doses, caffeine can have significant effects on the heart by changing the speed and regularity of the heartbeat. If you think your heartbeat is abnormal, check with your doctor.
Blood pressure: Very Well Mind reveals that studies have shown that caffeine consumption raises blood pressure, especially those with hypertension (high blood pressure).
Bone density: High coffee consumption has been linked to osteoporosis in men and women. In older women, studies have shown a link between high caffeine intake and lower bone density.
Metabolism: Caffeine doesn’t suppress the appetite, although it does increase the level of circulating fatty acids.
Is too much coffee bad for you?
Like many other drugs, it is possible to build up a tolerance to caffeine, which means you become used to its effects and need to take larger doses to achieve the same results. Over time, you may become physically and psychologically dependent on caffeine to function effectively.
Withdrawal symptoms vary, but can include fatigue, crankiness, a persistent headache, sweating, muscle pain, and sometimes anxiety.
The easiest way to break caffeine dependence is to cut down gradually, giving your nervous system time to adapt to functioning without the drug.
Free Dieting provides a guide on how the different levels of caffeine intake can affect you.