People who have a coffee allergy will have a reaction when they are exposed to the bean. Someone who is sensitive to or has an intolerance to caffeine or something else in coffee may also experience symptoms. It is important to know the difference between these conditions.
Doctors can help people with suspected allergies or sensitivities to coffee find a solution to their specific problems.
Prevalence and causes
An adverse reaction can be caused by the dust from coffee beans before they are roasted.
Allergic reactions to drinking coffee are very rare.
According to a study posted to International Archives of Allergy and Immunology, the dust from green coffee beans causes an allergic reaction in some of those who work with the beans. No recent medical literature mentions allergic reactions to drinking coffee, though rare cases have occurred in the past.
An allergic reaction caused by food, such as coffee beans, is actually due to an immune system response. The immune system recognizes compounds in the cells of coffee as invaders.
The immune system then responds to coffee in a similar way to how it would respond to pathogens, such as bacteria and viruses. It releases protective compounds, such as histamine, to isolate and destroy the intruding coffee. The symptoms of a coffee allergy are the result of this process.
Symptoms of a coffee allergy
A true coffee allergy can cause serious symptoms in the body, usually within the first hours after it has been drunk. Symptoms can affect many areas of the body and will usually get worse over time.
Symptoms of an allergic reaction to coffee include:
- skin rashes, such as hives or blotches of red skin
- nausea and vomiting
- trouble swallowing
- shortness of breath or difficulty catching a breath
- a wheezing cough
- stomach or abdominal cramps
- reduced color in the skin
- weak pulse or a sudden drop in blood pressure
- dizziness or loss of consciousness
Severe allergic reactions may lead to anaphylaxis, which can be life-threatening if left untreated. Anaphylaxis can cause swelling of the throat and mouth, blocking off the airways, while also adversely affecting the heart rate and blood pressure.
Anyone who experiences any of these symptoms should get medical attention right away. People who have a coffee allergy and have taken antihistamine medications or epinephrine should still seek medical attention to avoid any potential complications.
Coffee allergy vs. coffee sensitivity
Many people with coffee sensitivities mistakenly think that they are allergic to it. Sensitivity to coffee can create its own problematic symptoms, but they are usually not life-threatening.
Feelings of anxiety, unease, or irritability after drinking coffee may indicate a coffee sensitivity.
Symptoms of a coffee sensitivity can include:
- feelings of jitteriness and unease
- anxiety or nervousness
- trouble sleeping or insomnia
- upset stomach
- abdominal cramps
- elevated heartbeat or blood pressure
- involuntary muscle spasms
Symptoms caused by sensitivity to coffee will usually go away if the person stops drinking coffee.
People who are sensitive to coffee may have a gastrointestinal upset or symptoms connected to other issues may be getting worse. For example, coffee can make heartburn and symptoms of gastroesophageal reflux disease (GERD) worse. The caffeine in coffee can relax the sphincter at the lower end of the food pipe, causing stomach acid to leak up and irritate it.
Symptoms of too much caffeine vs. allergy symptoms
Allergies may be confused with the symptoms caused by having too much caffeine or sensitivity to caffeine. Many people who get sick from drinking coffee are simply seeing the effect of caffeine sensitivity.
Typically, the recommended caffeine consumption for adults is limited to 400 milligrams (mg) per day. This is around 4 small cups of home-brewed coffee. After that, many people will start experiencing symptoms.
People who do not have caffeine regularly, or those that are sensitive to caffeine, may experience symptoms after relatively small amounts of caffeine, such as 1 cup of coffee or tea. If a person is not used to caffeinated drinks, symptoms may occur because their body is not used to caffeine's effects and struggles to process and eliminate the caffeine from the system.
Too much caffeine is associated with similar symptoms to those of a coffee sensitivity. In addition to these symptoms, too much caffeine in someone who is caffeine-sensitive may cause symptoms, such as:
- chest pain
- heart palpitations
- mood swings, anger, or depression
- numbness in the extremities
- muscle pains
- shortness of breath
- headaches or migraines
- delusions or hallucinations
- cold sweats
- flu-like symptoms
- panic attacks
Although very rare, it is also possible to be allergic to caffeine itself. Some people may experience allergic reactions to the compound, which can lead to anaphylaxis.
Any new symptoms should be reported to a doctor or allergist immediately to discuss a plan of action.
Other ingredients in the coffee can also cause an adverse reaction.
Coffee beans contain many different substances that may cause a reaction in some people. For example, the beans may have come into contact with pesticides or chemicals during their growing and transportation.
Any of these factors could potentially cause an allergic reaction or intolerance in certain people.
People who drink coffee with milk or cream may be having a reaction to dairy. Heavily sweetened beverages may cause a reaction to sugar. Flavored syrups can also contain many other ingredients, which could be the culprit behind allergy or intolerance symptoms.
A recent study posted to Journal of Toxicology and Environmental Health found that various green coffee bean samples were contaminated with mycotoxins, which come from fungi on the beans. These toxins may survive the roasting process and be present in coffee, causing an allergic reaction.
Researchers noted that mycotoxin exposure is a health concern. Further studies will need to look into ways to limit exposure to these toxins.
It may help anyone who is uncertain about their allergies or sensitivities to keep a food journal, logging what they eat and drink and how they feel throughout each day. Over time, this journal can help people work out which foods to avoid.
Foods to avoid
People who have a reaction to coffee need to avoid the bean in all of its forms. This includes drinking it, eating it, or being exposed to the beans before roasting.
If a person is sensitive to caffeine, they may need to avoid foods such as chocolate and some energy bars.
People with sensitivity to caffeine need to avoid consuming the compound. Caffeine is found in:
- various teas including black, green, Oolong, Pu'er, and white tea
- energy drinks
- some soft drinks and sodas
- some workout bars or meal bars
Decaf coffee or tea may still contain a small amount of caffeine. In a person who is highly sensitive to it, this may be enough to cause a reaction.
Anyone with severe caffeine sensitivity will need to check labels carefully. Caffeine is added to many products, such as candy, gum, and even vitamins.
Some pain treatment medications also have caffeine in them. These must be avoided, and a doctor should be told of caffeine sensitivity before any medication is prescribed.
For those who are allergic or intolerant to coffee itself, some teas might be a good alternative. Tea leaves have less caffeine than coffee beans, but can still be a source of energy in the morning.
If a person enjoys coffee but caffeine upsets their system, there are alternatives made from chicory or roasted grains that can satisfy their morning habit and provide the same roasted flavor as a cup of coffee. Non-caffeinated herbal teas of any kind can replace coffee for many people.
When to see a doctor
Anyone experiencing new symptoms, or symptoms which get worse after drinking coffee, should see a doctor or allergist. They can help by administering tests and checking for any other influential factors.
Doctors may recommend an elimination diet, or recommend that someone keep a food journal of everything they eat and drink and records how they are feeling. Doing so can help identify any reactions that would normally go unnoticed.
Many people who experience negative reactions to coffee can work with a doctor or allergist to find a way to alleviate symptoms and avoid allergic or intolerance reactions to coffee.