Here’s How Coffee Can Be Both Good & Bad For You

It’s the world’s most widely used psychoactive drug

Photo by Nathan Dumlao on Unsplash


Some people love coffee so much or have such a habit that they drink it first thing in the morning. People have various reasons of drinking coffee such as increasing energy levels, feeling more alert, or because it’s too darn good.

We humans love coffee so much that caffeine that is naturally present in coffee is the world’s most widely used psychoactive drug. In the western world, around 80% of the population consumes caffeine in large amounts.

Because it is so widely used, there have been a ton of studies and researches into the health benefits of caffeine.

Caffeine is naturally present in tea and coffee but for the purposes of this story, I will be talking about both the good and bad aspects of coffee.

Pros of Coffee:

  • It improves energy levels and makes you more alert.
  • It reduces the risk of neurodegenerative disorders and depression.
  • It can help reduce the risk of cancer and diabetes.

Cons of Coffee:

  • Too much coffee can cause a dependency and/or addiction.
  • It can temporarily increase blood pressure.
  • It can negatively affect sleep.

It improves energy levels and makes you more alert.

A majority of people drink coffee to experience the effects of caffeine which is a central nervous system stimulant. This means that caffeine increases activity in the brain and spinal cord which makes you more alert, less tired, and more focused.

This is primarily why people drink coffee in the morning so they get over their slump and tiredness. It’s also a reason why caffeine is a common ingredient in medications that help treat headaches and pain. Caffeine is a good painkiller which is why it’s combined with other ingredients to relieve pain.

When you drink coffee, the caffeine gets naturally absorbed into the bloodstream from where it travels to the brain and inhibits the neurotransmitter adenosine.

Adenosine is a central nervous system depressant that helps promote sleepiness at night. Levels of adenosine rise throughout the day which is why we feel sleepy at night when adenosine levels reach a high point.

Because caffeine inhibits adenosine, it makes you feel less tired and more alert. This comes quite in handy when people want to pull off all-nighters.

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It reduces the risk of neurodegenerative disorders and depression.

Once absorbed, caffeine naturally travels to the brain where it exerts its principal effects.

As such, research has shown that regular coffee consumption can reduce the risk of neurological diseases such as Alzheimer’s and dementia.

Alzheimer’s disease is the most common neurodegenerative disease in the world and accounts for 60–70% cases of dementia.

One study showed that people who regularly drink 3–5 cups of coffee every day have a 65% decreased risk of getting Alzheimer’s and/or dementia. Coffee has been shown to improve brain function mainly because it is able to increase neuronal firing in the brain and promotes the release of other neurotransmitters such as dopamine.

Because coffee increases neuronal activity in the brain, it is able to help regulate mood and reduce the risk of depression. It is able to do that because caffeine blocks natural chemicals in the brain that depress mood such as adenosine which ultimately increases excitability in the brain thus improving mood.

A Harvard study published in 2011 showed that women who consistently drank 4 or more cups of coffee every day had a 20% lower risk of becoming depressed.

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It can help reduce the risk of cancer and diabetes.

Coffee has been shown to reduce the risk of cancer and tumor growth.

In one large study that examined several other studies, researchers found that coffee reduced oral and pharyngeal cancer by 31%, liver cancer by 54%, colon cancer by 13%, endometrial cancer by 27%, melanoma by 11%, and prostate cancer by 11%.

Another study also found that people who regularly drink 4–5 cups of coffee every day have a 15% lower risk of colorectal cancer.

Based on these results, coffee appears to inhibit the growth of tumors which is the root cause of cancer. Consistently drinking coffee can help reduce the risk of these cancers over the long run.

Around 34 million Americans have diabetes while almost 88 million have prediabetes. Diabetes doubles the risk of many cancers such as liver, endometrial, and pancreas while increasing the risk of breast and bladder cancer by 20-50%.

Reducing the risk of diabetes is an excellent way to prevent other problems down the line such as increased susceptibility to cancer and heart disease.

Coffee appears to also reduce the risk of diabetes.

Studies have shown that people who drink four or more cups of coffee every day have a 50% lower risk of type 2 diabetes.

Another large review of 18 studies showed that each cup of coffee consumed a day led to a 7% reduced risk of type 2 diabetes.

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Too much coffee can cause a dependency and/or addiction.

Having a regular habit of drinking coffee can sometimes lead to a dependency or addiction where if you stop consuming coffee, you will get withdrawal symptoms such as headache, fatigue, drowsiness, irritability, etc.

One study involved 16 people who were regular consumers of high, moderate or no caffeine and they took part in a word test after going without caffeine over the night. Only high caffeine users showed a preference for caffeine-related words and had strong caffeine cravings.

The reason why addiction and withdrawal symptoms occur can be best explained by what caffeine does to the brain. When you drink coffee, caffeine gradually reaches the bloodstream where it can cross the blood-brain barrier and enter the brain.

Caffeine closely resembles a inhibitory neurotransmitter called adenosine that is naturally present in the brain. Because of this, caffeine fits into brain cell’s receptors for adenosine and blocks off adenosine from binding to those receptors. Adenosine promotes sleepiness and tiredness and since caffeine is occupying the adenosine receptors, it decreases tiredness and generates a sense of alertness.

When adenosine is blocked, both dopamine and adrenaline which are stimulants work more effectively which causes the body to become more alert and active.

People who regularly consume caffeine have a change in the brain’s chemical and physical characteristics over time. The brain grows more adenosine receptors since most of the receptors have been occupied due to caffeine and this is why habitual coffee drinkers develop a tolerance over time. Due to the growth of additional adenosine receptors, it takes more caffeine to block more of these receptors and achieve the same effect.

Because the brain has been physically and chemically altered due to caffeine, suddenly giving up on caffeine affects the brain profoundly. The brain gets used to the regular consumption of caffeine and when caffeine is suddenly stopped, withdrawal symptoms such as headache, fatigue, irritability, etc. start to appear.

It usually takes around 7–12 days after stopping caffeine to get over the symptoms and dependency.

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It can temporarily increase blood pressure.

Because caffeine is a central nervous system stimulant and helps increase levels of alertness and focus, it also temporarily increases blood pressure.

This rise in blood pressure is most pronounced in people who are not used to the effects of caffeine or don’t drink a lot of coffee.

Regular coffee drinkers don’t really experience a significant rise in blood pressure because their bodies have been acclimatized to the regular consumption of caffeine.

A study that involved 15 volunteers (healthy nonsmokers, six were regular coffee drinkers) found that a triple espresso did not elevate blood pressure in habitual coffee drinkers but raised the systolic pressure on average by 13 mm Hg and the diastolic pressure by 7 mm Hg in people that did not consume coffee.

Additionally, that study also found that decaffeinated espresso (where most of the caffeine has been removed) did not raise blood caffeine levels, but it boosted the average systolic blood pressure of nondrinkers by 12 mm Hg.

This shows that coffee can temporarily increase blood pressure in people who don’t regularly consume coffee. Caffeine may not even be responsible for the rise in blood pressure as the decaffeinated espresso showed and some other natural compounds in coffee may be responsible.

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It can negatively affect sleep.

Caffeine is a central nervous system stimulant and blocks sleep-inducing chemicals such as adenosine in the brain. The good part is that it can increase energy levels and alertness. The bad part is that it can make it harder for you to sleep at night and affects sleep quality if consumed a few hours before bedtime.

Caffeine has a half-life of around 5 hours meaning if you consume 30 mg of caffeine, then you will have around 15 mg remaining in your body after 5 hours. One study showed that caffeine’s effects start to become more noticeable within 45 minutes of consuming caffeine.

Of course, the more caffeine you consume, the harder it will be for you to fall asleep. That is why it is often recommended that people avoid caffeine for four to six hours before bedtime.

One study investigated how the timing of caffeine intake affected sleep. Researchers gave 12 healthy adults 400 mg of caffeine either immediately before bedtime, three hours before bedtime, or six hours before bedtime.

The time it took all three groups to fall asleep and the time they spent awake at night increased by a significant amount.

As 8-oz cup of brewed coffee contains around 95 mg of caffeine which won’t really affect your sleep but drinking too many cups of coffee especially a few hours before bedtime could have a negative impact on sleep quality.

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Final Thoughts

Overall, coffee is a healthy beverage that can have health benefits for a regular coffee drinker. Some of the negative effects such as elevated blood pressure and addiction can be managed by not drinking too much coffee throughout the day and especially before bedtime.

Once people get used to the effects of coffee, it can lead to withdrawal symptoms if people decide to go cold-turkey on it. Slowly reducing the amount of caffeine you intake through the day can help lessen the severity of withdrawal symptoms.

However, regularly consuming safe amounts of coffee can benefit one’s health in so many ways and helps ward off many diseases.

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