Coffee — Good or Bad?

Coffee is rich in many of the nutrients naturally found in coffee beans.

A typical 8-ounce (237 gram) cup of coffee contains (1):

• Vitamin B2 (riboflavin): 14% of the DV
• Vitamin B5 (pantothenic acid): 12% of the DV
• Vitamin B1 (thiamine): 3% of the DV
• Vitamin B3 (niacin): 3% of the DV
• Folate: 1% of the DV
• Manganese: 2% of the DV
• Potassium: 2% of the DV
• Magnesium: 2% of the DV
• Phosphorus: 0.6% of the DV

This may not seem like a lot, but try multiplying it with the number of cups you drink per day — it can add up to a significant portion of your daily nutrient intake.

But coffee really shines in its high content of antioxidants.

In fact, there are enough antioxidants in coffee that it can be viewed as a healthy plant food (2).

Caffeine is the most commonly consumed psychoactive substance in the world (3).

Soft drinks, tea and chocolate all contain caffeine, but coffee is the biggest source.

The caffeine content of a single cup can range from 30–300 mg, but the average cup is somewhere around 90–100 mg (1).

Caffeine is a known stimulant. In your brain, it blocks the function of an inhibitory neurotransmitter (brain hormone) called adenosine.

By blocking adenosine, caffeine increases activity in your brain and releases other neurotransmitters like norepinephrine and dopamine. This reduces tiredness and makes you feel more alert (4).

A randomized controlled trial demonstrated that both caffeinated and decaf coffee can lead to a short-term boost in brain function, improving mood, reaction time, vigilance and general cognitive function (5).

Older studies have shown that caffeine can also boost metabolism by 3–11% and exercise performance by 11–12%, on average (6, 7, 8, 9).

However, some of these effects are likely short-term. If you drink coffee every day, you will build up a tolerance — and with it, the effects will be less powerful (10).

Alzheimer’s disease is the world’s most common neurodegenerative disease and a leading cause of dementia.

Studies have shown that coffee drinkers have up to a 65% lower risk of developing Alzheimer’s disease (11).

Parkinson’s is the second most common neurodegenerative disease and is caused by the death of dopamine-generating neurons in the brain.

Coffee drinkers have a lower risk of Parkinson’s disease. The more coffee people drink, the lower the risk (12).

Type 2 diabetes is characterized by elevated blood sugar levels due to resistance to the effects of insulin.

This common disease has increased in recent decades and, as of 2021, affects over 537 million people or 1 in 10 globally (13).

Interestingly, studies show that coffee drinkers may have a reduced risk of developing this condition. According to a 2021 review, drinking coffee often may lower type 2 diabetes risk by protecting the liver and preserving beta cell function (14).

A 2018 systematic review shows similar results, showing that coffee provides significant antioxidant and inflammatory effects (15).

Your liver is an incredibly important organ that has hundreds of different functions in your body.

It is sensitive to excess alcohol and fructose intake.

The end stage of liver damage is called cirrhosis and involves most of your liver turning into scar tissue.

A 2016 review concludes that 2 cups of coffee a day in patients with pre-existing liver disease may lower the incidence of cirrhosis, fibrosis, liver cancer, and death (16).

A 2021 review concluded that all types of coffee, including decaf, may protect against chronic liver disease (17).

Liver cancer is also common. It is the second leading cause of cancer death worldwide. Coffee drinkers have a significantly lower risk of liver cancer (18).

Depression is the world’s most common mental disorder and leads to a significantly reduced quality of life.

In one 2018 study, people who drank the most coffee had a 63% lower risk of becoming depressed (19).

In a 2019 cohort study, suicide ideation appeared to decrease in Korean men and women who had regular to moderate caffeine intake daily (20).

Given that coffee drinkers have a lower risk of many common, deadly diseases — as well as suicide — coffee could help you live longer.

A 2022 study with over 400,000 participants concluded that drinking 2 to 3 cups of different types of coffee per day was associated with significant reductions in cardiovascular disease and death (21):

It wouldn’t be right to only talk about the good without mentioning the bad.

The truth is, there are some negative aspects to coffee as well, although this depends on the individual.

Consuming too much caffeine can lead to jitteriness, anxiety, heart palpitations and even exacerbated panic attacks (22).

If you are sensitive to caffeine and tend to become overstimulated, you may want to avoid coffee altogether.

Another unwanted side effect is that it can disrupt sleep. A 2023 review concluded that coffee should be consumed nearly 9 hours before bedtime to get a restful night’s sleep (23).

If coffee reduces your sleep quality, try to avoid drinking coffee after 2:00 p.m.

Caffeine can also have diuretic and blood pressure-raising effects, though these usually dissipate with regular use. A 2023 systematic review showed that coffee drinkers experienced a lower risk of high blood pressure. However, additional research is needed to confirm the study’s results (24).

A 2021 review found that Brazilian non-smokers who drank coffee drinks had a decreased risk of hypertension (25).

Another issue with caffeine is that it can lead to addiction (26).

When people consume caffeine regularly, they become tolerant to it. It either stops working as it did, or a larger dose is needed to produce the same effects (10).

When people abstain from caffeine, they get withdrawal symptoms, such as headaches, exhaustion, brain fog and irritability. This can last for a few days (27).

Tolerance and withdrawal are the hallmarks of physical addiction.

Some people opt for decaffeinated coffee instead of regular.

Decaffeinated coffee is usually made by rinsing coffee beans with chemical solvents.

Each time beans are rinsed, some percentage of the caffeine dissolves in the solvent. This process is repeated until most of the caffeine has been removed.

Keep in mind that even decaffeinated coffee does contain somecaffeine, just much less than regular coffee.

There are some things you can do to maximize the beneficial health effects of coffee.

The most important is to not add a lot of sugar to it.

Another technique is to brew coffee with a paper filter. Unfiltered coffee — such as from a Turkish or French press — contains cafestol, a substance that can increase cholesterol levels (28).

Bear in mind that some coffee drinks at cafés and franchises contain hundreds of calories and a lot of sugar. These drinks are unhealthy if consumed regularly.

Finally, make sure to not drink excessive amounts of coffee.

Some people — especially pregnant women — should definitely avoid or severely limit coffee consumption.

People with anxiety issues, high blood pressure or insomnia might also want to reduce their intake for a while to see if it helps.

A 2019 study found that those who drank more than 6 cups of coffee a day had a moderate increase in cardiovascular risk, but this association was not proven to be a cause of this risk (29).

Additionally, some people are concerned that drinking coffee may increase their risk of cancer over time.

While it’s true that roasted coffee beans contain acrylamides, a category of carcinogenic compounds, there is no evidence that the small amounts of acrylamides found in coffee cause harm.

In fact, most studies suggest coffee intake has no effects on cancer risk or may even reduce it (30, 31)

That said, coffee can have important beneficial effects on health for the average person.

If you don’t already drink coffee, these benefits are not a compelling reason to start doing it. There are downsides as well.

But if you already drink coffee and you enjoy it, the benefits appear to far outweigh the negatives.

Given that the association is strong and consistent among studies, coffee may indeed play a positive role in your health.

Though it was demonized in the past, coffee is likely very healthy for most people, according to scientific evidence.

If anything, coffee belongs in the same category as healthy beverages like green tea.