The health effects of coffee are controversial. Despite what you may have heard, there are plenty of good things to be said about coffee. It’s high in antioxidants and linked to a reduced risk of many diseases.
However, it also contains caffeine, a stimulant that can cause problems in some people and disrupt sleep.
This article takes a detailed look at coffee and its health effects.
Coffee Contains Some Essential Nutrients and Is Extremely High in Antioxidants
Coffee is rich in many of the nutrients naturally found in coffee beans.
A typical 8-ounce (240-ml) cup of coffee contains (1):
- Vitamin B2 (riboflavin): 11% of the DV
- Vitamin B5 (pantothenic acid): 6% of the DV
- Vitamin B1 (thiamine): 2% of the DV
- Vitamin B3 (niacin): 2% of the DV
- Folate: 1% of the DV
- Manganese: 3% of the DV
- Potassium: 3% of the DV
- Magnesium: 2% of the DV
- Phosphorus: 1% 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.
Coffee Contains Caffeine, a Stimulant That Can Enhance Brain Function and Boost Metabolism
Caffeine is the most commonly consumed psychoactive substance in the world (4Trusted Source).
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.
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 (5, 6Trusted Source).
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 (13Trusted Source).
Coffee May Protect Your Brain From Alzheimer’s and Parkinson’s
Alzheimer’s disease is the world’s most common neurodegenerative disease and a leading cause of dementia.
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 Much Lower Risk of Type 2 Diabetes
Type 2 diabetes is characterized by elevated blood sugar levels due to resistance to the effects of insulin.
This common disease has increased tenfold in a few decades and now affects over 300 million people.
One review of 18 studies in 457,922 people associated each daily cup of coffee with a 7% reduced risk of type 2 diabetes (25Trusted Source).
Coffee Drinkers Have a Lower Risk of Liver Diseases
Your liver is an incredibly important organ that has hundreds of different functions in your body.
The end stage of liver damage is called cirrhosis and involves most of your liver turning into scar tissue.
Coffee Drinkers Have a Much Lower Risk of Depression and Suicide
Depression is the world’s most common mental disorder and leads to a significantly reduced quality of life.
In one Harvard study from 2011, people who drank the most coffee had a 20% lower risk of becoming depressed (31Trusted Source).
In one review of three studies, people who drank four or more cups of coffee per day were 53% less likely to commit suicide (32Trusted Source).
Some Studies Show That Coffee Drinkers Live Longer
Given that coffee drinkers have a lower risk of many common, deadly diseases — as well as suicide — coffee could help you live longer.
Long-term research in 402,260 individuals aged 50–71 found that coffee drinkers had a much lower risk of dying over the 12–13 year study period (33Trusted Source):
The sweet spot seems to be at 4–5 cups per day, with men and women having a 12% and 16% reduced risk of death respectively.