The Dark Side of Decaf: 5 Startling Side Effects You Shouldn't Ignore

Many of us start our day with a hot cup of coffee. But if caffeine isn't right, decaf coffee is the most widely consumed option. However, it is important to be aware of the side effects of decaf coffee. Contrary to popular opinion, it does not lead to dehydration or increased heart rate, but there are still some side effects.

How is decaf coffee made?
Before we get to the ill effects of decaf coffee, it is important to understand how it is made and whether decaf coffee contains caffeine or not.
As the name suggests, decaffeinated (or decaf, for short) coffee is coffee with most of the caffeine removed (97% - to be exact). A serving of decaf coffee contains about 2 to 5 mg of caffeine, compared to 50 to 75 mg in regular coffee (2).

What are the side effects of decaf coffee?-

1. May cause heart complications
Decaffeinated coffee can raise bad cholesterol (LDL cholesterol) levels. These effects were not observed in the caffeinated variant (4). Decaf coffee was found to increase certain blood fats linked to metabolic syndrome.

2. Rheumatoid arthritis can worsen
Decaf coffee consumption was linked to an increased risk of rheumatoid arthritis (8). Surprisingly, caffeinated coffee did not pose this risk.

3. May cause acidity
Decaf coffee was found to increase serum gastrin concentrations (10). Gastrin is a hormone that stimulates the release of stomach acid. When this happens in excess, it can lead to symptoms of acidity (11).

4. May interfere with iron absorption
In general, coffee contains chlorogenic acid, and so does decaffeinated coffee. Chlorogenic acid was found to inhibit nonheme (plant-based) iron absorption (13).

5. May cause headache and drowsiness
These may be more withdrawal symptoms. Individuals who regularly consume coffee may also often experience headaches, drowsiness, and fatigue when given decaf coffee (14).