Coffee — Good or Bad?

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, looking at both the positives and negatives.

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.

In fact, the typical Western diet provides more antioxidants from coffee than from fruits and vegetables combined (2, 3).

Coffee Contains Caffeine, a Stimulant That Can Enhance Brain Function and Boost Metabolism

Caffeine is the most commonly consumed psychoactive substance in the world (4).

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, 6).

Numerous studies demonstrate that caffeine can lead to a short-term boost in brain function, improving mood, reaction time, vigilance and general cognitive function (7, 8).

Caffeine can also boost metabolism by 3–11% and exercise performance by 11–12%, on average (9, 10, 11, 12).

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 (13).

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.

Studies have shown that coffee drinkers have up to a 65% lower risk of developing Alzheimer's disease (14, 15, 16).

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

Coffee drinkers have a 32–60% lower risk of Parkinson's disease. The more coffee people drink, the lower the risk (17, 18, 19, 20).