Coffee, like any other food or drink on the market, can be associated with side effects for some people. It is estimated that up to 20% of American’s have some sort of food intolerance. Intolerance to coffee is not that uncommon and can manifest differently in each person. Allergy to coffee is less common but not unheard of. Reactions, whether they are from allergy or intolerance, can come from compounds in the coffee or to the caffeine itself. Food intolerance, whether it is to coffee or other things that are ingested, is often a delayed response to a compound in the food. Allergies are immune reactions that typically cause the release of histamine.


Caffeine Intolerance: Symptoms of Coffee Allergies

There are more than 1,000 chemical compounds in coffee, including caffeine. Identifying the exact component of coffee causing the intolerance is impossible. But there are some more common compounds that have been looked at that are likely culprits.

Coffee is high in histamine which can set off what looks like an allergic reaction but it doesn’t occur through the typical allergy mechanism. Instead, the histamine from the coffee causes an inflammatory reaction that can be quite severe in some people. Histamine can cause a variety of symptoms, many of which overlap with symptoms related to intolerance or allergy to coffee, such as hives, rashes, shortness of breath, palpitations, abdominal pain, and many more. Some people are more sensitive to the effects of histamine in food and many of them have a condition known as mast cell activation syndrome, which in itself can lead to an increase in the amount of histamine in the body.

Coffee contains caffeine, which can cause reactions related to the effects of caffeine on the body. The typical symptoms caused by caffeine are jitteriness, heart racing and anxiety. These symptoms, however, can also be due to an allergic reaction to caffeine. In the case of allergy, there are often other additional signs of the reaction, including abdominal pain, rashes, numbness and tingling, flu-like symptoms that could progress to anaphylaxis. But the truth is that the symptoms themselves don’t always correlate with the type of reaction since there is so much overlap.


Symptoms of coffee intolerance:

Coffee intolerance or a coffee allergy can lead to a variety of symptoms such as:

  • Headaches or migraines
  • Skin rashes, hives and acne
  • Racing heart or palpitations
  • Shortness of breath
  • Sweats
  • Jitteriness
  • Dizziness
  • Anxiety
  • Numbness in hands and feet
  • Fatigue
  • Anaphylaxis
  • Abdominal pain and cramps
  • Congestion
  • Mouth ulcers

Some symptoms are specifically due to the effects of caffeine on the body. Genetically, we have enzymes that help us metabolize caffeine. Those who are poor metabolizers are more likely to have symptoms of excess caffeine, such as jitteriness, anxiety, and palpitations. Some symptoms are related to an allergy or intolerance to the caffeine that comes from the body recognizing the caffeine as foreign. The body then starts attacking the caffeine and in doing so attacks itself, causing inflammation. This can lead to an allergic reaction and even in extreme cases, anaphylaxis. If the reaction is an intolerance and not a true allergy, the symptoms can still be very similar and can range from mild to severe and can include non-specific symptoms like headache, fatigue and abdominal pain.


Number of Cups of Coffee To Drink Per Day

I recommend my patients drink 1-2 cups of coffee maximum per day and often I recommend none since I treat sensitive patients who have a history of intolerances to many things.


Ways to Reduce Caffeine Intake

Typically, weaning off coffee slowly over the course of several weeks instead of cold turkey will result in less side effects, especially if you have been drinking a lot of coffee or caffeinated beverages. One trick that some of my patients have found useful is diluting their regular coffee with decaffeinated coffee. In other words, start with 3/4 of a cup of regular coffee and 1/4 of a cup of decaf and then over time decrease the amount of regular and increase the amount of decaf.


Mycotoxins in Coffee

Coffee has also been found to contain high levels of mycotoxins. Mycotoxins are toxins produced by fungus and mold. We know that much of our food supply is contaminated with mold, particularly dried foods, like coffee, and cereal grains. Coffee has been shown to contain a particular mycotoxin, known as ochratoxin, that is produced by a number of different molds that grow on coffee beans. Ochratoxin has been studied and found to be associated with kidney disease, cancer and damaging effects on the brain. In addition to its dangerous effects on the body, mold and its toxins can induce allergic reactions and intolerances.

To read more of my thoughts on coffee intolerance, click here to read the latest Women’s Health article on this topic “My Upset Stomach Turned Out to be a coffee intolerance”