WHAT IS CAFFEINE AND WHAT DOES IT DO TO THE HUMAN BODY?

Curious about caffeine? You’ve come to the right place!

If you drink enough coffee to find yourself at Home Brews Coffee, you likely have questions about your caffeine consumption. What is it doing to your body? Is it a net positive or negative? And what is caffeine, anyway?

I’m here to answer all those questions and more from an unbiased scientific perspective. To put it briefly, coffee and caffeine have plenty of health benefits, provided you’re conscientious about the amount you consume and your overall health. Keep reading for the details

What Is Caffeine?

Caffeine is a naturally occurring compound found in plants, including coffee, tea, cocoa, and guarana. It can also be synthesized in a lab and added to energy drinks, sodas, and soft drinks.

What Is Caffeine Composed Of?

Caffeine is an organic molecule comprised of carbon, nitrogen, hydrogen, and oxygen atoms, with the chemical formula C₈H₁₀N₄O₂.

The metabolism of caffeine by the body breaks it down into three compounds: Paraxanthine, Theobromine, and Theophylline. 

• Paraxanthine is a nervous system stimulant and is believed to help improve short-term memory and response times and protect against neurodegeneration. 
• Theobromine is a mild stimulant and reduces blood pressure by dilating the blood vessels. It can also cause sweating, headaches, and nausea. 
• Theophylline opens the air passages in the lungs and can be used to treat symptoms of respiratory issues including chronic bronchitis, emphysema, and asthma.

Is Caffeine A Drug?

Yes, caffeine is a drug, as classified by the Food and Drug Administration (FDA). Indeed, it is the world’s most widely consumed psychoactive drug. 

Interestingly, it only has one clinical use – the treatment of breathing and lung problems in premature infants. But given its relative safety, caffeine is used extensively for off-label reasons, like easing migraines or improving athletic performance.

Is Caffeine Addictive?

Caffeine is scientifically considered a dependence, not an addiction. Prolonged intake alters your brain chemistry, requiring increasing doses of caffeine to receive the same levels of stimulation.

Caffeine dependence can lead to withdrawal symptoms, including headaches, muscle aches, fatigue, nausea, and mental fog. Symptoms normally dissipate within 7 to 12 days.

What Does Caffeine Do To The Body?

Caffeine acts as a central nervous system stimulant in the human body. The most common short-term effect of caffeine on the human body is the one we all know and love, its ability to reduce drowsiness and increase focus and mental alertness.

It can also improve athletic performance by increasing energy and delaying the onset of fatigue. Caffeine can reduce appetite and increase the energy used for digestion, which can help with weight loss.

Caffeine And The Brain

Caffeine keeps you awake by blocking the activity of adenosine, a chemical compound that promotes sleep. Adenosine builds up in the body during the day and attaches itself to receptors in the brain, causing a feeling of drowsiness. Caffeine prevents this attachment by bonding to the receptors in place of adenosine (1).

Caffeine has been associated with a reduced risk of depression and Parkinson’s, conditions linked to low dopamine levels in the brain. Caffeine does not increase dopamine but makes your brain more sensitive to it, as well as providing protective benefits for dopamine receptors. 

Caffeine acts as a brain stimulant, increasing brain activity. In small amounts, it improves alertness and energy, but in larger amounts, it can overstimulate, leading to increased anxiety, insomnia, and headaches. One study showed that drinking more than six cups of coffee daily over extended periods can shrink the size of the brain (2).

Related: Nootropic coffee

Caffeine And The Kidneys

Caffeine increases stress on the kidneys and the risk of kidney stones but has also shown some beneficial effects against chronic kidney disease (CKD).

Caffeine stimulates the central nervous system, increasing blood pressure and causing the kidneys to work harder. At the same time, caffeine’s ability to improve vascular function can reduce the risk of developing chronic kidney disease and prolong the life of those with CKD (3).

What Are The Benefits Of Caffeine?

Along with the short-term boost just described, positive long-term benefits of caffeine consumption include improved mental health, a decreased risk of developing Alzheimer’s and Parkinson’s disease, and improved memory and mental acuity.

There are also numerous positive health effects associated with drinking coffee, including reducing the risk of type 2 diabetes, cardiovascular disease, and certain cancers – not to mention a reduced overall risk of mortality (4). However, it is hard to determine whether these stem from coffee’s caffeine or antioxidant content.

What Are The Symptoms Of Too Much Caffeine?

The FDA recommends no more than 400 mg of caffeine per day for a healthy adult – roughly 3 or 4 cups of coffee (5). Negative short-term effects of overconsumption of caffeine include nervousness, headaches, confusion, stomach irritability, sleeping problems, increased blood pressure, increased urination, and heartburn. 

Risks of caffeine over the long term, include issues during pregnancy, bladder instability, an increased risk of osteoporosis, and worsening of symptoms of anxiety and depression. You also run the risk of developing caffeine dependence, and caffeine withdrawal may cause short-term effects such as headaches, irritability, and muscle aches.

It is very difficult to do serious damage to your health by drinking too much coffee, but it is possible to overdose on caffeine if you experiment with caffeine anhydrous – the pure form. There have been several deaths attributed to caffeine toxicity in this context (6).

Why Does Coffee Contain Caffeine?

Brewed coffee has caffeine because coffee plants have evolved to use caffeine to protect themselves from predators and other plants and to attract pollinators (7).

Caffeine is toxic to insects and small herbivores and deters these animals from eating the plant. When coffee leaves fall on the ground, the caffeine is absorbed into the soil, preventing competing plants from growing nearby. The caffeine in coffee flowers addicts pollinators like bees, helping the plant flourish.

How Much Caffeine Is In Coffee?

The amount of caffeine in a cup of coffee varies depending on the brewing method, the recipe, and the type of coffee beans.

Espresso has the highest concentration of caffeine, with 2240-2730 mg/L, but is consumed in smaller serving sizes. A 1-oz shot of espresso contains 70-80 mg caffeine. 

Related: Can espresso be decaf?

Regular drip coffee has a more moderate caffeine content of 680-740 mg/L but is consumed in larger servings. An 8-oz cup of regular coffee contains 115-175 mg of caffeine. 

Some of the strongest coffee beans are sourced specifically for their high caffeine levels and contain much higher concentrations. A single 8-oz cup of Death Wish coffee contains roughly 450 mg of caffeine – more than the recommended safe daily amount!

Decaffeinated coffee contains less caffeine than regular coffee, but it is not completely caffeine-free. Decaf coffee contains around 7 milligrams of caffeine per 8-oz serving. If you want a completely caffeine-free drink, you’ll need to consider a coffee alternative like chicory coffee.

Related: What type of coffee drink has the most caffeine?

Along with caffeinated coffee, other natural sources of caffeine include green tea, black tea, chocolate, guarana, and yerba mate.

Final Thoughts

Caffeine is a stimulant that occurs naturally in many plants – our favorite, coffee, among them. When consumed in moderation, caffeine may offer numerous health benefits, including increased alertness, energy, and mental clarity, as well as longer-term prevention of several common diseases. 

So if you’ve been worried your coffee consumption is bad for your health, you’ll be happy to hear it’s more likely the opposite is true! Just keep it to no more than three or four cups of coffee a day.