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How does caffeine affect our health?

General | November 17, 2014 | Author: The Super Pharmacist


How does caffeine affect our health?

The pros and cons of drinking coffee regularly. How much is too much? Caffeine, as is generally known, is what your body has to deal with when you have a cup of coffee. Whether it’s that regular serving of cappuccino or a flat white, the kick in coffee is caffeine. What some people may not realise is that caffeine food sources go way beyond coffee classifications. Soft drinks, chocolate, candy, gums, and energy drinks contain caffeine; so does tea, which is probably the most popular drink on the planet after water.

Caffeine is psychoactive, which means it crosses the blood-brain barrier and affects the mind. Chemically it is a xanthine alkaloid, a bitter crystalline substance. Principal natural sources of caffeine are coffee plant seeds (coffee beans), tea bush leaves and kola tree fruit (kola nuts).

How does Caffeine affect our Health?

Caffeine has widespread effects on bodily functions. Let’s examine these system-wise.

Cardiovascular System

  • Increased blood pressure
  • Palpitations
  • Arrhythmias

Respiratory System

  • Slightly improved lung function

Gastrointestinal System

  • Increased gastric acid secretion
  • Reduced intestinal food absorption

Urinary System

  • Diuretic: increased urination

How does Caffeine affect our Health?Nervous System

  • Increased alertness
  • Increased focus
  • Increased mental performance
  • Decreased sleep
  • Irritability
  • Restlessness

Many of these effects are brought about by the ability of caffeine to antagonise (block) adenosine receptors. Adenosine tends to dampen mental activities.

Other Effects

  • Increased metabolism
  • Increased physical performance
  • Reduced fatigue
  • Aids painkiller medications, e.g. in alleviating migraines
  • Some beneficial role in losing weight and preventing obesity
  • Reportedly lowers the risk of liver cirrhosis, Parkinson’s disease, type II diabetes, and colorectal cancer

The effects of caffeine begin to appear within 30 minutes of its intake and it can take the body about 6 hours to metabolise 50% of it.

The Pros and Cons of drinking Coffee regularly

From what is listed above, it can be inferred that caffeine has a multitude of effects at multiple levels. From the coffee-drinker’s perspective, some of these are exactly what made him/her go for that cup of coffee in the first place, while others are undesirable and make coffee a mixed bargain.


  • Increases mental focus and performance
  • Helps night shift workers maintain alertness
  • Lowers the risk of liver cirrhosis, Parkinson’s disease, type II diabetes, and colorectal cancer
  • Provides antioxidants to get rid of oxygen free radicals in the body
  • Helps in alleviating migraine attacks or headaches in some people
  • Purportedly helps lose weight


  • Insomnia
  • Irritability
  • Increased anxiety
  • Increased stress
  • Increased blood pressure
  • Diuresis and dehydration
  • Can weaken bones, especially in elderly women
  • It is addictive as caffeine withdrawal is symptomatic

How much caffeine is too much?

That is the question. When you realise that the benefits that coffee has to offer are bundled with the risk of unwanted effects, you want to know that magic amount which would enhance your performance while minimising the cons.

How much caffeine is too much?For a start, everyone should know the threshold below which you are relatively safe and above which you are putting your health in danger.

That threshold is 400 mg of caffeine per day. 

Since a regular cup of coffee usually contains around 100 mg of caffeine, 4 cups should normally be the upper limit. Anything above that may make you irritable, anxious, and sleepless.

Furthermore, there is a lethal dose as well: 10 gm or 80 to 100 cups of coffee one after the other. This seems implausible but cases have been reported of caffeine overdose deaths. The culprit usually is dry caffeine pills which can deliver greater doses. But the question remains, what is my ideal number of coffee cups per day? The answer isn’t straightforward. Before we get to a conclusion, there are some other facts about caffeine that we need to consider:

Different people are differentially sensitive to caffeine

What this means is that the same amount of coffee will have different intensity of effects in different people. Some people may lie sleepless all night after that mistimed cup of coffee late in the evening while others may have no trouble going to sleep just after they have had a mugful. And so it goes with palpitations, restlessness, and anxiety, which affect some persons more than others. Caffeine-induced anxiety is a distinct psychiatric entity and prone individuals are advised to refrain from caffeine containing products.

Different people manifest different effects of caffeineDifferent people manifest different effects of caffeine

Some people may experience chiefly cardiovascular symptoms such as palpitations, tachycardia and hypertension, with only mild mental effects. On the other hand, others may notice predominantly neurological manifestations such as arousal, restlessness and insomnia, and nothing wrong with their heartbeat.

Long-term users need more amounts to get the same effect

Caffeine is metabolised in the liver. For long-term coffee takers, liver enzymes get the time to develop into more efficient systems of caffeine disposal. For such persons more cups of coffee will be required to achieve the same effect that a novice drinker would get from a smaller dose.

Women metabolise caffeine faster than men

Women inherently metobolise coffee faster but oral contraceptives will reverse this. Furthermore, for women in the reproductive age group, less than 300 mg of caffeine per day, and if pregnant, less than 200 mg per day is recommended. This is for those who are already regular users. It’s better not to start a coffee habit when pregnant. Women in these two groups should consult their doctors about caffeine use and also consider the levels given above as guidelines.

So there is no fixed number of coffee cups that would be suitable for everyone. If you are a coffee-person, too much may not be that much; if you are not, a little may be too much. The final answer will reveal itself once you get out there and experiment with your daily caffeine intake and check how it affects you. As long you stay within the safety levels, you are free to experiment. Soon you will find out what works best for you. You need that kick in caffeine, but you don’t want it to hurt you.  Australia’s best online discount chemist


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