It is a common misconception that caffeine or coffee are genuinely harmful. I’ve heard it mentioned countless times how coffee raises your blood pressure and therefore is bad for the heart.
I’ve also read how coffee can reduce chances of awful things like type II diabetes and Parkinsons, and in this article I am going to review the evidence and answer the question Is Coffee bad for you.
This post is part of a series:
Coffee nutrition facts
Coffee, especially if it is ground on the spot, actually contains some important vitamins and minerals.
According to Nutrition data, coffee is a decent source of these nutrients:
- A cup may contain about 0.2mg of Riboflavin (Vitamin B2), which is 11% of the RDA.
- It may also contain 0.6mg of Pantothenic Acid (Vitamin B5), which is 6% of the RDA.
- A cup may contain 7.1mg of Magnesium, around 2% of the RDA.
- It is also a source of Potassium, containing 116mg or 3% of the RDA.
- It is also a decent source of Manganese, containing 0.1mg or 3% of the RDA.
Coffee may also contain some other vitamins and minerals in minor quantities. The amount of nutrients differs significantly, coffee that is brewed from fresh ground high-quality beans will most likely contain a much higher amount of nutrients than cheap, low-quality varieties.
Certain substances in coffee may inhibit absorption of certain minerals, mainly iron and zinc.
You might be interested in the difference in health benefits between coffee and green tea, if so I’ve written a great post about tea vs coffee.
Is Coffee bad for you?
Coronary Artery Disease
The research on coffee and coronary artery disease have been mixed, but the majority of them seem to point to it not having any significant effect on cardiovascular disease. However, some of them have, and therefore it is a possibility that coffee could increase risks of heart disease but if it does then it is a very small effect.
It is a fact that coffee does increase blood pressure, especially for people who are not used to drinking it. However, for regular coffee drinkers the effects diminish, but might add around 1-2mmHg to both systolic and diastolic blood pressure. It would be a good idea for people with high blood pressure to reduce their intake.
Osteoporosis and fractures
There have been several studies that showed reduced bone mineral density and increased risk of hip fracture, especially at higher doses, and a few studies that showed no association. It might be a good idea for postmenopausal women to minimize their intake, and make sure their Vitamin D levels are adequate.
Some studies have found an association with coffee drinking and spontaneous abortion in pregnant women, and others have found caffeine to increase chances of impaired fetal growth. It is a good idea for pregnant women to minimize their intake of caffeine and many health authorities recommend staying under 300mg/day.
Is Coffee good for you?
Type II diabetes.
There have been several research studies that show how coffee drinking can drastically reduce chances of developing type II diabetes, with numbers as high as a 50% reduction. Take note that this is one of the most rapidly developing diseases in western countries today.
Coffee drinking has been found to reduce chances of developing Parkinson’s disease in men, but the results in women have been mixed.
It seems that women undergoing hormone replacement therapy have increased chances of Parkinson’s when drinking coffee, but women who haven’t undergone such therapy show a benefit in the same way as men.
It seems that coffee drinking may reduce chances of developing colorectal cancer, with reductions varying from about 20-50%. This is the third most commonly diagnosed cancer in the world, so a reduction of this magnitude is quite important.
Coffee drinking may reduce chances of developing liver diseases such as Cirrhosis, and a form of liver cancer called Hepatocellular carcinoma. It seems that people who already had liver issues saw the most benefit, and this reduction was particularly evident in people suffering from hepatitis B and C.
If someone were to ask me “Is coffee bad for you?” or “Is coffee good for you”, I would say that it has both health benefits as well as negative effects. In my opinion, the benefits do outweigh the negatives but every individual should decide for himself.
It does seem that the processing method matters, filtered coffee has less of some harmful substances, mainly diterpenes, which raise cholesterol levels. There are more diseases that coffee has been shown to have an effect on that I choose not to discuss here, such as Alzheimers and dementia.
For people who have hypertension or a family history of heart disease, and pregnant women as well as postmenopausal women, it might be a good idea for them to minimize caffeine or aim to stay under 300mg/day.
According to the studies, it might actually be a good idea to drink coffee for people with a genetic propensity to type II diabetes or Parkinson’s, or for people suffering from Hepatitis.
For healthy people, I would say that if you like coffee, by all means drink all you want without feeling guilty. Take note however that the risk of harmful effects does increase with a higher dosage, and that caffeine addiction and caffeine withdrawal symptoms are very real phenomenons that can be quite unpleasant for some people.
Sources: Higdon, Jane V. and Frei, Balz (2006) ‘Coffee and Health: A Review of Recent Human Research’, Critical Reviews in Food Science and Nutrition, 46:2, 101 – 123.