What is Food Allergy? Everything You Need to Know!

Medically reviewed by Mary Ahern MS, RDN, RYT September 30, 2024| Written by Zenda Nel

What is Food Allergy? Everything You Need to Know!

Food allergies are so common that we all know at least one person who is allergic to some or other food item. Over the past generation, food allergies have increased so much that it has become a major health issue affecting220 million people globally.

Several experts attribute these rising numbers to lifestyle changes likeunhealthy eating habits and urban living.

We know that when someone is allergic to a food item like shellfish it can make them very ill, but why? What happens in the body to make the person so ill? 

It’s because their immune system reacts to a certain protein in the food item - as if it’s a bacteria or virus that must be destroyed to protect the body. 

Substances that cause allergies are called allergens. To destroy the allergen, the immune system makes antibodies called immunoglobulin E (IgE) to defend the body. These antibodies attach to cells that release chemicals, prompting an allergic reaction. 

Food items are just one type of allergen. Other allergens may include, mites, pollen, insects, grass, drugs, and rubber. 

What are Some Signs of Food Allergies?

People usually show symptoms of an allergy about two hours after ingesting the particular allergen, but it can also happen within minutes. 

Symptoms can range from mild to life-threatening and can show up in different parts of the body, including the skin, face, mouth, throat, stomach, and lungs. Mild symptoms can be itchy skin that is merely uncomfortable. However, a severe allergic reaction, called anaphylaxis, can cause:

  • Swelling of the bronchial tissues
  • Dramatic drop of blood pressure and shock (anaphylactic shock)
  • Suffocation due to swelling of the throat and larynx
  • Increased heart rate

These symptoms can lead to loss of consciousness and death.

Typical foodallergy symptoms include:

  • Dry, red, and itchy skin 
  • Hives 
  • Swollen lips, face, and eyes
  • Coughing, wheezing, breathlessness, hoarse voice
  • Sneezing, and itchy or runny nose
  • Feeling sick 
  • Feeling light-headed or dizzy
  • Abdominal pain
  • Diarrhea

Tree nuts such as almonds, cashews, and walnuts can cause a host of symptoms, including

  • Abdominal pain, cramps, nausea and vomiting, diarrhea
  • Difficulty swallowing
  • Itchy mouth, throat, eyes, skin, or itching of other areas
  • Nasal congestion or a runny nose
  • Shortness of breath

What Causes Food Allergies?

Food allergies are caused when the immune system makes a type of antibody against an allergen, such as wheat, eggs, shellfish, or peanuts. 

When an individual eats one of these items, the immune system mistakenly identifies the food as harmful and releases loads of chemicals, including histamine. This sparks a flood of symptoms which vary depending on where the chemicals were released.

For instance, when released in the nose, they cause difficulty breathing, wheezing, and sneezing.

Can a Food Allergy Appear Suddenly?

Yes, a food allergy can appear out of the blue. You may at first not realize that you are having an allergic reaction to shellfish when you break out in hives after enjoying your favorite crab salad for lunch. 

While it's true that most food allergies start during childhood, they can appear at any time. 

Many adults suddenly can't eat a food item that they have enjoyed countless times in their lives. This is one of those inexplicable phenomena in life that no one can explain, including scientists.

According toFARE (Food Allergy Research & Education), common childhood allergies like milk, soy, and egg can disappear over time. But allergies to peanuts, tree nuts, fish, and shellfish are usually for life.

What are common Food Allergies? 

Many food items can cause allergic reactions, but thenine most common food items that cause the vast majority of allergic reactions, are: 

  • Milk
  • Eggs
  • Fish (e.g., bass, flounder, cod)
  • Crustacean shellfish (e.g., crab, lobster, shrimp)
  • Tree nuts (e.g., almonds, walnuts, pecans)
  • Peanuts
  • Wheat
  • Soybeans
  • Sesame

Around170 different foods are known to cause allergic reactions in some people.

What is the Easiest Way to Test for Food allergies?

The most common food allergy test is askin prick test (SPT). It doesn't endanger the individual and can even be used for infants. You can get your results immediately after the test, which is very helpful.

When you go for an SPT, your doctor may ask you to stop taking antihistamines for a couple of days before the test.

During the test, a little bit of the suspected food allergen is dropped on your forearm or back. The doctor then pricks the skin gently with a needle to allow the allergen to enter the skin. More than one allergen can be tested this way.

An allergy to the food allergen will show up as redness, swelling, or a bump where the skin is pricked. This reaction will appear within 15 – 29 minutes.

A SPT is not a hundred percent reliable. A positive result is reliable only 50 percent of the time and a negative result can be relied upon about 95 percent of the time. 

In fact, a positive result is not enough for a diagnosis; it merely indicates that your body has made antibodies to a particular allergen. A blood test may confirm the allergy.

Of course, if the patient has a severe reaction (anaphylaxis), the positive SPT confirms a severe food allergy.

A negative SPT result can help to rule out a suspected food as the root of allergic reactions.

Is it Possible to Cure Food Allergies? 

Researchers at Johns Hopkins say it will take at least another10 years to find a real cure for allergies. Currently, there is no cure for allergies. The only trusted way to avoid allergic reactions to a food item is to simply not eat the food at all. 

Scientists are experimenting with a treatment called oral immunotherapy. This treatment involves ingesting small amounts of the allergen or having it placed under your tongue. The dose is then gradually increased. Scientists are using this method on children in the hope of retraining their immune systems to tolerate the food without an allergic reaction.

The U.S. Food and Drug Administration recently approved the first oral immunotherapy drug for children between 4 and 17 years old who are allergic to peanuts.

Remedies to Treat Allergy Symptoms

The best way to deal with a food allergy is to avoid that food completely. However, if a food allergy only causes mild symptoms, the following remedies might ease your symptoms.

1. Ginger to Treat Nausea

Ginger is known to relieve nausea. If one of your symptoms is nausea, you might benefit from the ability of ginger to speed up digestion and reduce bloating and cramping caused by trigger foods. 

Boil peeled or grated ginger in water for a refreshing ginger tea.

2. Probiotics

Scientists believe that unbalanced bacteria in the gastrointestinal (GI) tract, also known as dysbiosis, may contribute to food allergies. Research has shown thatprobiotics can benefit the human immune system and gut, preventing and treating various diseases, including suppressing allergic symptoms by reducing the generation of allergen-specific IgE antibodies. 

To increase your intake of probiotics, include yogurt, kefir, kombucha, sauerkraut, and pickles in your diet.

3. Traditional Chinese Medicine (TCM)

Traditional Chinese Medicine or TCM is one of the oldest medicinal practice systems that has been used for the treatment of a wide range of health conditions, including allergies. 

People have found TCM effective for their allergies and many research laboratories are investigating the herbal medicinal system because it has shownpromise in food allergy treatment. More research is necessary, but it doesn't stop you from visiting a TCM specialist for treatment.

4. Green Tea

Astudy in Japan found that methylated epigallocatechin gallate (EGCG) - a compound in green tea, inhibited the production of allergy-causing chemicals in mice. This either eliminated reactions or reduced their intensity. 

Scientists expect similar results in humans and suggest adding green tea to the diet. 

Green tea also contains the flavonoid quercetin, whichinhibits the release of histamine. And so, it may reduce allergy symptoms like itching, swelling, and runny nose.

Other sources of quercetin are onions, broccoli, apples, berries, grapes, and wine.

How Does Fiber Help with Food Allergies? 

Scientists have noted that at the same time as our diets have decreased in fiber, there has been an increase in allergies. Researchers at Monash University in Australia conducted a study in mice that showed ahigh-fiber diet enriched with vitamin A caused less severe allergic reactions to peanuts in mice bred to be allergic to peanuts.

Among other factors, the high-fiber diet boosted immune responses that protect against food allergies. The researchers concluded a diet low in fiber could be behind food allergies, and a high-fiber diet enriched with vitamin A could potentially protect against food allergy risk.

In addition,a comprehensive scientific review looked at the role of dietary fiber in regulating the microbiome and immune system and preventing allergic diseases. Studies on the impact of fiber on disorders like asthma, allergic rhinitis, and hyperimmune response to common allergens were reviewed. The finding was that fiber has significant potential to protect against allergy disorders.

What Foods Should You Eat to Recover From Allergy?

You can't really recover from a food allergy. If you are allergic to a certain food, the only thing to do is to avoid that food. If you have a mild allergy to a certain food, you can try the above-mentioned remedies to ease your symptoms.

How to Manage a Food Allergy?

While most symptoms of food-related allergies are mild and limited to itchy skin, a runny nose, or abdominal issues, a severe food allergy can give rise to anaphylaxis, which can be fatal. Mild allergies are treated with antihistamines.

 However, severe reactions like anaphylaxis require an injection of epinephrine, which acts fast. 

If you, or someone close to you, have been diagnosed with an allergy, you must be able to identify the early signs of anaphylaxis so you can act promptly by administering an epinephrine injection.

To reduce the risk of a fatal incident, take the following precautions:

  • Avoid foods that you are allergic to.
  • Always read food labels.
  • Make sure you know the early signs and symptoms of an allergic reaction so you can act immediately. Many incidences of a severe allergic reaction occur when a person accidentally ingests an allergen, so you always have to be vigilant.
  • Learn how to use an epinephrine auto-injector and when to use it.
  • Always have two doses with you – some people can have a repeat severe reaction.
  • Don't ignore mild symptoms – they can escalate fast and become serious. Remember, any allergic reaction can end up in anaphylaxis. 
  • Invest in an allergy medical alert bracelet so those around you and first responders can take the appropriate action in case of an emergency.

FAQs

Can You Reverse a Food Allergy?

Reversing a food allergy is currently not possible, but you can pursue treatments like acupuncture, and remedies like ginger or green tea to relieve allergic reactions. 

Why are Food Allergies on the Rise?

There is no clear reason why allergies are on the rise.Factors that may play a role, include

  • Genetics
  • Environmental triggers
  • Use of antibiotics early in life
  • Vitamin D deficiency
  • The age when a child starts eating solid foods

How Long Will Food Allergy Last?

A child may outgrow a food allergy, such as an allergy to milk, egg, soy, or wheat. Research has revealed that half of children have outgrown their allergy by the time they arefive years old.

On the other hand, allergies to peanuts, tree nuts, fish, and shellfish tend to last throughout a person's lifetime.

Conclusion

Food allergies are on the increase worldwide. A food allergy is an immune system response to a food that doesn't give most people any problems. There is currently no cure for food allergies – the best way to manage a food allergy is to avoid the food that causes allergic symptoms.

Most food allergies develop in childhood, but adults can also develop a food allergy. The good news is that many children outgrow their allergies, especially the most common ones, such as milk, wheat, eggs, and soy.