Why Do Humans Have Allergies?

When the winter snows begin to melt away, and the flowers begin to bloom, this reminds many people around the world of one thing… allergy season! Allergies come in many shapes and sizes, as do the symptoms of an allergic reaction, but there is still something oddly mysterious about this behavior of the body. While most allergies can easily be managed, the whole subject raises a very simple question – why do so many humans have allergies in the first place?

The Science of Allergies

When we are born, our bodies are essentially a blank canvas, meaning that our immune system is completely fresh, and untainted by the world around us. Our first exposure to any potential pollutants, irritants, bacteria or viruses usually comes as we exit the womb. That is the first time that our immune system must kick into action. This early exposure to parasites, microbes and other unwanted substances will cause our immune system to react, in an effort to rid the body of this foreign invader.

After the immune system’s receptors identify something as abnormal, one of the countless antibodies in the body will be triggered – sort of like an alarm system within the body. At this point, following this initial exposure, the body will produce that antibody on a large scale, effectively adding it to the defenses of the body. These antibodies will be present in your body from that point on, waiting until it recognizes its “trigger” substance or pathogen again.

Despite being an amazing aspect of our evolution, the immune system is not perfect, and does make mistakes. During the mass-production phase of antibodies following the initial exposure, some of them may not be copied correctly, and these tiny mutations can create antibodies that might respond to the wrong triggers. For example, if antibodies attack proteins from the body itself, that is caused an autoimmune disease, which are notoriously difficult to treat. Some examples of this are lupus, rheumatoid arthritis and HIV/AIDS.

However, if antibodies are triggered by other types of proteins, such as those found in certain foods, commercial materials, products or environmental elements, those conditions are called allergies. In these, the body overreacts to a harmless substance, as though it were a dangerous pathogen, resulting in allergy symptoms. For those people who have allergies, they know that an allergic reactions can range in severity, from a mild stuffy nose, itchy eyes or a skin rash to gastrointestinal distress, hives, difficulty breathing and even anaphylactic shock.

Generally, the symptoms are a type of inflammation, which is caused by the release of histamines from the mast cells near the affected area. For example, if you are allergic to bees and you get stung, the mast cells will immediately release the histamines in that area to allow white blood cells to seek out and neutralize the perceived pathogen. This increase in blood will cause inflammation in the area (swelling around the bite), as well as pain and possible soreness.

Therefore, while allergies are often considered harmless, the hypersensitivity of the immune system can be a dangerous thing, and should be taken seriously, particularly if you have a number of diagnosed allergies.

The Future of Allergies

The reason that allergies have recently become such a hot topic in popular medicine and media is because the number of people with allergies is growing significantly, and has been for decades. Since the exact cause of allergic reactions remains a bit of a mystery, this steady and measurable increase has been quite a puzzle for researchers.

Many people point to the increased levels of hygiene precautions for young children. The fear of every virus and pathogen has created new generations of children who have been ultra-protected from any potential microbes and pathogens from a very early age. Many children essentially live in a bubble, and are not granted the early exposure to various microbes while their immune system is first developing. What this means is that they will lack the antibodies (on a large scale), that their bodies will need as they grow and come into contact with various allergens.

For millions of years, human beings did not live in a world where sterile environments, antibiotics, antibacterial wipes, and face masks existed. However, in the past few centuries, as our understanding of medicine and the human body has improved, so too have the measures to protect ourselves from foreign agents and pathogens. While this is good for preventable diseases that are possibly life-threatening, it is generally weakening the immune system by preventing it from establishing an early defensive shield against more allergens.

Experts predict that this trend in allergies will continue to rise, as the obsession with personal hygiene and putting our children in metaphorical bubbles is only growing.

There are also many studies arguing that our modern world is creating more allergens than ever, with new synthetic materials, additives and substances constantly being introduced to the body for the first time with every passing year. For that reason, there is also a spike in the number of people over 40 years old presenting with new allergic symptoms they have never experienced before.

As it stands now, roughly 1 in 3 people in the world suffer from an allergy-related health concern, ranging from mild to quite sever. Within the next decade, it is expected to increase to more than 50% of the global population.

Can You Protect Against Allergies?

Once you have an allergy, it can be difficult to eliminate it, but not impossible. Dietary interventions can help to re-balance your immune system, while regular allergy shots can also boost your body’s tolerance for certain substances.

When you do start suffering from symptoms, antihistamines are quite effective, but general avoidance of allergenic substances is also an options. Perhaps most importantly, as parents, don’t try to protect your child from every conceivable speck of dirt, playground slide or pile of leaves. Children should be allowed to develop their own immune defenses by exploring and engaging with the world around them!


  1. American Collage of Allergy, Asthma & Immunology
  2. MayoClinic
  3. National Public Radio
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About the Author:

John Staughton is a traveling writer, editor, publisher and photographer who earned his English and Integrative Biology degrees from the University of Illinois. He is the co-founder of a literary journal, Sheriff Nottingham, and the Content Director for Stain’d Arts, an arts nonprofit based in Denver. On a perpetual journey towards the idea of home, he uses words to educate, inspire, uplift and evolve.

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