An Overview of Caffeine Allergy

Many people depend on caffeine to get them going every day. But that can be a bad idea for people with a caffeine allergy or intolerance.

Most people can drink caffeinated coffee, tea, or soda without issue. Others may experience:

• Diarrhea
• Jitteriness
• Insomnia
• Other symptoms

Heavy consumption—more than 400 milligrams (mg) of caffeine, or four cups of coffee per day—can do this to anyone.

For some, though, it can happen after just one cup of java. That's about 95 mg of caffeine.

Negative reactions to modest amounts of caffeine may be due to a non-allergic food intolerance or, less often, an allergic reaction.

In this article, you'll learn the difference between a caffeine allergy and an intolerance, how they're diagnosed and treated, and some information to help you live with an allergy or intolerance.

You'll also learn about common coffee molds, which could be the cause of your allergic reaction.

Caffeine Allergy vs. Intolerance

It may be hard—both for you and your healthcare provider—to immediately identify caffeine as the source of your symptoms.

Beyond that, deciding whether it's a food allergy or intolerance can be difficult. Some important nuances may help you tell the difference.

Caffeine Allergy

A caffeine allergy develops when the immune system incorrectly identifies caffeine as a harmful substance. It then releases an antibody called immunoglobulin E (IgE) into the bloodstream.

The body then responds with:

• Inflammation
• Dilated blood vessels and tissues
• Skin rash with itching (pruritus), hives (urticaria), or swelling (edema)

Skin rashes are perhaps the main differentiating feature between a caffeine intolerance and a caffeine allergy. Other symptoms include:

• Anxiety
• Chest pain
• Cold sweats
• Dizziness
• Fatigue
• Headaches
• Heart palpitations
• Joint pain
• Muscles aches

Unlike with some allergies, respiratory symptoms are uncommon.

Food intolerance and caffeine allergies can manifest with symptoms in anywhere from a few minutes to two hours.

However, with a caffeine allergy, the severity of symptoms is typically linked to how fast they develop.

Those that develop quickly may, in rare cases, progress to a potentially life-threatening allergic reaction known as anaphylaxis.

Mold on Coffee Beans

It is also possible that certain fungi on processed coffee or tea leaves may trigger an allergic response unrelated to caffeine.

Many of these fungi produce spores that the body recognizes as biological threats, particularly if you have an existing mold allergy.

Some molds also produce toxins called "mycotoxins," such as ochratoxin A, a common food contaminant.

In large amounts, OTA may be harmful to your health. Thus far, though, most of the evidence of harm has been in animal studies. Experts don't yet know what effect it has on human health.

In animals, OTA is believed to harm the liver, kidneys, immune system, brain, and nervous system. It's also been tied to cancer and birth defects.

However, even if OTA can have these effects in humans, several studies show that the amount most Americans consume isn't a cause for concern.

In a 2017 study, researchers tested products from grocery stores in the U.S. over a two-year period. They found that most foods and beverages had no detectable OTA. The highest levels were in:

• Dried fruits
• Breakfast cereals
• Infant cereals
• Cocoa

Even from these foods, though, they concluded that the risk is negligible.

That's well and good for most people, but if you have a mold allergy, you may still react to small amounts of OTA and other mycotoxins.

If you react to coffee or tea (which also may contain these molds) but not to other sources of caffeine, ask your healthcare provider about testing for a mold allergy.

Because mycotoxins can also grow on nuts, grains, and other crops, you may need to limit the amount of these foods you consume.

If you're concerned about mycotoxins in coffee, buy high-quality, USDA-certified organic coffees, as they may have lower levels.

Caffeine Intolerance

Food intolerance—also known as non-allergic food sensitivity—involves problems digesting certain foods rather than an allergy to them. While potentially distressing, a food intolerance is rarely serious.

An intolerance is often caused by the lack of a specific enzyme needed to metabolize a specific nutrient (like lactose). When your body can't break down the food properly, you end up with symptoms such as:

• Bloating
• Diarrhea
• Gas
• Spasms
• Stomach aches

A caffeine intolerance is often caused by its effect on the endocrine (hormone) system.

Caffeine suppresses a chemical called adenosine, which helps you sleep, and increases the production of adrenaline, which gives you a burst of energy.

When your body doesn't process caffeine properly, it can have a magnified effect. That leads to too much adrenaline and symptoms including:

• Jitteriness
• Insomnia
• Lightheadedness
• Facial flushing
• Rapid heartbeat
• Rapid breathing
• Profuse sweating
• Stomach upset

Diagnosis

Caffeine allergies and intolerances are difficult to diagnose by symptoms alone. Even if you have a rash or hives, you may allergy testing to see if the allergen is caffeine or some other ingredient.

With coffee, it's even possible that certain types of beans or roasting techniques may be more problematic than others.

Allergy skin testing and IgE antibody blood tests are the fastest and most effective means to diagnose a caffeine allergy.

Less commonly, genetic testing may be used to identify mutations in the ADORA2A gene. Positive tests point to a caffeine allergy, while negative tests suggest an intolerance.

Treatment

The main treatment for a caffeine allergy or intolerance is cutting it out of your diet.

If you suspect caffeine is the problem, it's reasonable to stop consuming it and see if the symptoms go away. You can find caffeine in:

• Black, green, and white tea (but not herbal or rooibos/red tea)
• Colas
• Chocolate (cocoa or cacao)
• Energy drinks
• Certain headache medications (like Anacin)
• Over-the-counter stimulants (like NoDoz)

Even a product labeled "decaffeinated" may contain trace amounts of caffeine that can stimulate the central nervous system in people who are especially sensitive.

Coping

Quitting caffeine is easier said than done. Caffeine withdrawal can cause headaches, fatigue, and irritability. You may even experience nausea and flu-like symptoms.

These symptoms typically start within 12 to 24 hours of stopping caffeine. They can take between two and nine days to fully subside.

You can do several things to wean yourself off caffeine with the least amount of stress.

Another Hot Drink

If coffee is part of your morning ritual, replace it with a hot, non-caffeinated beverage. Don't drink decaf coffee—it contains between 2 milligrams (mg) and 15 mg in an 8-ounce cup.

Better options include:

• Herbal tea
• Warm apple cider
• Hot water with lemon

You might also want to try a caffeine-free product called Teeccino. It's made of roasted chicory and designed to taste like coffee.

Drink More Water

Drinking plenty of water throughout the day can reduce your craving for cola or caffeinated energy drinks.

If you're used to cola, switch to sparkling water, which can keep you well hydrated without excess sugar.

Get Some Exercise

Take a long walk or exercise to counteract fatigue. Fresh air may give you a much-needed boost when your energy starts to lag, as well.

Even a 20-minute workout can get your heart pumping and stimulate the production of endorphins to help elevate your mood and alertness.

Take Time to "Crash"

If you're used to drinking a lot of caffeine, taking away the stimulant may cause you to "crash" for a couple of days.

You can prepare for this by setting aside time for extra sleep and relaxation.

Summary

While neither is common, it's possible to have a caffeine allergy or intolerance. Allergies involve an immune-system response while intolerances are caused by digestive problems.

Allergy symptoms can include an itchy rash, hives, anxiety, dizziness, and headaches. Intolerance symptoms may be bloating, diarrhea, jitteriness, and rapid heartbeat.

Your healthcare provider can test you for a caffeine allergy. If it's negative, an intolerance may be to blame.

The main treatment for either condition is avoiding caffeine. You may also benefit from allergy medications or shots.

Giving up caffeine may lead to withdrawal symptoms. You can ease them by replacing coffee with a non-caffeinated hot beverage, drinking lots of water, getting some exercise, and resting.

A Word From Verywell

When used in moderation, the effects of caffeine—such as increased alertness—are often beneficial. But if you're one of the rare people with a caffeine allergy or intolerance, it can have really unpleasant effects.

Having to give up your favorite beverage is tough. But avoiding the offending substance can make you feel a lot better.

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