Effects of Caffeine on the Human Body

A cup of coffee or tea is something that most of us consume on a daily basis for the benefits and effects of caffeine on the human body. And in case you are not familiar with caffeine, it is a white and bitter substance present naturally in more than 60 plants, including tea leaves, coffee beans, cacao pods, and others. In fact, caffeine is not only present in tea and coffee but it is present in some chocolates too. Caffeine is also used as an ingredient in a variety of energy drinks and even in some medications.

The Food and Drug Administration (FDA) has given two varied opinions about this ingredient. According to it, caffeine can be both a food additive and a drug. Every day, millions of people consume caffeine to alleviate fatigue, increase wakefulness, and improve their focus at work. However, caffeine not only has its benefits and healthy effects on the body but there can be some other adverse effects of caffeine too. Thus, we are with everything about caffeine and how caffeine affects the human body. 

Effects of Caffeine on the Human Body

Humans eat caffeine on a regular basis in various forms like tea, coffee, beverages, and even desserts like chocolates. Upon consumption, it passes into your bloodstream from your stomach. Caffeine then stimulates your central nervous system, including your nerves, brain, and the spinal cord, awakening wakefulness. However, caffeine can also release acid into your stomach and gut. Thus, some people feel a tinge of heartburn or indigestion after consuming it.


When you eat or drink caffeine, it enhances dopamine signaling in the brain. Not only that but caffeine also increases the flow of chemicals like cortisol and adrenaline in your body. The whole mechanism makes you feel fresh and keeps you alert and awake.

Benefits and Good Effects of Caffeine?

Apart from keeping you alert and awake, caffeine has many more effects on the human body. These effects of caffeine include a number of benefits for the human body including the following:

Effects of Caffeine on Weight Loss

Even though you need to be in a calorie deficit to lose weight, in some cases, caffeine can indirectly help you lose weight loss. Caffeine can lower a person’s appetite and may have a thermogenic effect in some cases. Thus, it may help in weight loss in an indirect way.

Effects of Caffeine on Alertness

Merely consuming 75mg of caffeine may increase your attention and alertness manifold. Because of this, many people like to have a cup of coffee before starting their everyday office work.

Effects of Caffeine on Sports Performance

The consumption of caffeine may also improve physical performance during endurance exercise which makes it a viable pre-workout meal option. However, the effects remain short-term. And while research is still going on, past studies like the CAIDE Study showed that people who drank coffee on a regular basis correlated with a lower risk rate of Dementia and Alzheimer’s Disease.

Effects of Caffeine on Brain Function

The primary function of caffeine is to affect adenosine receptors which are used to promote sleep. In other words, consuming caffeine will keep you awake and alert. Other than this, according to an Australian study, caffeine can correlate to a slower cognitive decline rate. Although, this claim is still being researched before it is completely confirmed

Effects of Caffeine on Liver

As per the Alimentary Pharmacology and Therapeutics journal, drinking coffee can be related to lower rates of cirrhosis which is known as the scarring or fibrosis of the liver. Caffeine is also linked to lower inflammation in patients that have hepatitis C infections. Furthermore, caffeine is considered to lower the risk of hepatocellular carcinoma liver cancer as well.

Effects of Caffeine on Eye Spasms

In case you face eye twitching or eye spasms quite often, you will be surprised to know that an Italian study has linked the consumption of coffee with blepharospasm. As per this study, people who drank coffee had a lower risk of developing blepharospasm.

What are the Side Effects of Caffeine on the Human Body?

The consumption of caffeine not only has its benefits but also comes with some side effects. When consumed in excess, caffeine may lead to various issues like:

  • Anxiety Disorders: Do not consume caffeine in excess if you have anxiety issues. Depending on the amount of caffeine intake, it may worsen your condition.
  • Bleeding Disorders: In case you have some sort of bleeding disorder, the chances are that your doctor must have advised you not to consume caffeine. This is due to the reason that caffeine can worsen bleeding disorders in some cases.
  • Heart Ailments: Stimulants like caffeine can result in a faster heart rate and even cause serious issues like arrhythmias.
  • Diabetes: Caffeine can affect your blood sugar levels because of which its dosage has to be monitored if you are pre-diabetic or already have diabetes.
  • Diarrhea: Excessive consumption of caffeine may lead to hyperacidity. In the worst-case scenario, you may as well fall prey to diarrhea.
  • High Blood Pressure: Consuming caffeine in excess may increase blood pressure for people with high blood pressure. Thankfully, it is not a major concern for people who don’t have blood pressure issues.
  • Low Bladder Control: Caffeine can even affect your bladder control making you visit the washroom again and again.

How Much Caffeine Should I Consume?

If you consume caffeine in moderation, it doesn’t harm your health. But if you overdo its consumption, expect to experience the above-listed side effects. As per a survey, an average adult consumes 200 mg of caffeine a day, equivalent to 3-5 ounce cups. Taking up to 400mg of caffeine does no harm. The side effects start when you go beyond this limit. Although, the safe limit for consumption of caffeine varies from person to person as per their gender, size, and their sensitivity to caffeine.

Who Should Avoid Consuming Caffeine?

Consumption of caffeine in any form is not safe for everyone. Therefore, you must be careful about adding it to your diet. If you cannot decide whether coffee is good for you or not, get in touch with a doctor or a healthcare professional first as they can suggest the right dosage.

Nonetheless, avoid caffeine if you have one of the following conditions:

  • Sleep disorders like insomnia from high dosage of caffeine
  • Ulcers or GERD
  • Migraines or chronic headaches
  • High blood pressure
  • Anxiety
  • Irregular or fast heartbeat
  • If you take certain medications, including stimulants, asthma medications, heart medicines, and antibiotics.
  • If you are a teenager, pregnant, or breastfeeding a child

Because of these effects of caffeine, you might consider stopping taking it in the future. Although, when taken regularly, a sudden stoppage of caffeine consumption can lead to withdrawal symptoms such as fatigue, headache, irritation, anxiety, muscle pain, etc. It is important to reduce the dosage gradually to avoid experiencing withdrawal symptoms.


Whether you want to stay alert during work or wish to have a tea break after working for hours, the majority of people consume caffeine on a daily basis. Caffeine may be beneficial if you need help waking up or focusing. But the excessive consumption of this ingredient can also lead to various health issues. Thus, make sure that you are only consuming caffeine to a limit with a healthy dosage.

We hope that you are now clear on the benefits and effects of caffeine on the body. These should help you in making wiser choices and live a much healthier life. Make sure to share your thoughts and comment down below.

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