In this blog series I plan to look deeper into the cause of food allergies. I want to understand why allergies have such a wide spectrum of symptoms, ranging from a running nose to complete anaphylaxis resulting in throat swelling and shock. If we could learn more about the underlying cause of food allergies could we then start to modulate the reaction to allergen exposure?
As a Naturopathic Physician I am trained to look beyond the presenting symptoms right to the underlying cause of disease so that our treatment goes right to the source of the problem. In addition to my professional interest, I am also a parent with a child with anaphylactic food allergies and am desperate to understand what could possibly be causing my son’s allergies and find out if there is more we can do other than just avoid the foods he is allergic to. So today, I am setting out to try and find some answers by exploring something I know little about – Mast Cell Disorder – to see if there might be a connection that could be helpful. I don’t promise any definitive answers; rather, I want to share my thought process to see if we can get any closer to increasing our understanding of what causes this potentially life-threatening condition.
What initially started me thinking about this idea was reading some of the more progressive research on genetic testing and using information about how defects in certain genes allow us to understand the disease process. When my child was first diagnosed with atopic dermatitis, asthma, and food allergies I was told it was all in his genes. This ‘triad of conditions’ shares the same underlying genetic cause so we often see the three conditions showing up together. As I research more about the role of genetics and the role they play in disease the more I start to question other causes or contributing factors that encourage the way our genes express themselves. In the case of people with the triad, one of the major players is histamine; the single molecule responsible for the classic symptoms of an allergic reaction – hives, tissue swelling, red and itchy skin.
Histamine is contained in a kind of white blood cell called a ‘mast cell’. When a foreign protein (such as a food allergen) is found in our body it triggers the release of histamine granules from these mast cells – a process known as ‘mast cell degranulation’.
How long this takes and how much of the foreign protein it takes to trigger this reaction varies from person to person and this raises an important question – why does the severity of a reaction vary? And, why do some people have a mild reaction while others have life-endangering symptoms?
To answer this we have to look to another key player in allergic reaction, an immunoglobulin antibody called IgE which play a significant part in the allergic process. An allergic reaction starts when we are first exposed to an allergen (a foreign protein, or antigen), the most basic of which are pollen, food, and medications. The presence of this foreign body stimulates what are known as ‘B cells’ to produce IgE antibodies. These IgE molecules attach to several kinds of cells but it is the mast cells that are key in this reaction. The next time we are exposed to that antigen the mast cells that are already ‘primed’ with IgE trigger the release of histamine from within the mast cell. And, as we have already seen, it is the histamine that is responsible for the symptoms of an allergic reaction.
When you are tested for allergies, we are generally looking at the levels of IgE total levels present in your blood as well as how much IgE your body produces in response to various antigens such as dairy, nuts, trees, etc. In my practice, I have found that patients who have high levels of IgE in their blood tend to have stronger inflammatory reactions to foods. This leads me to ask, “If we can reduce the amount of IgE produced in the body, would that help reduce the severity of an anaphylactic reaction?” Perhaps the answer lies with the mast cells.
Mast Cell Activation Disorder
There is a condition called mast cell activation syndrome or mast cell activation disorder (MCAD). This is considered an immunological condition where the mast cells release excessive amounts of various chemicals, including histamine. People with this condition have a normal number of mast cells but they secrete too much histamine.
Mast cell activation syndrome is not a well-known condition and is therefore not understood by many physicians however, as I research more about it I start to see a correlation between this and the inflammatory, allergenic conditions of food allergies and asthma. MCAD is also associated with autism, celiac and a condition called Eosinophilic Esophagitis (EOE) which inflames the esophagus through an allergic reaction. EOE can go misdiagnosed for years as ‘just food allergies’ or even chronic heartburn; often these are the people who report reacting to airborne exposure to a particular food.
MCAD is recognized to be a genetic condition but is difficult to diagnose because it can ebb and flow over the years then suddenly, out of the blue, symptoms can ramp up and people start to experience severe histamine reactions in any part of the body. And therein lies another complication; because mast cell can occur anywhere in the body MCAD can show up as an array of conditions anywhere in the body. One of the most common is the digestive system. This is due to a) the length of the intestines and b) how much of the immune system is contained within the intestines. Celiac and unexplained abdominal pain are two of the more common conditions associated with MCAD.
This could mean that food allergies are just a symptom of an underlying condition such as MCAD. If this is true then many people diagnosed with food allergies may actually have MCAD.
If this is the case then perhaps the way to reduce the severity of an allergic reaction is to reduce the chief suspect – histamine. With lower amounts of histamine in your system, the fewer weapons your mast cells will have available with which to attack any foreign invaders. This could make the difference between a few hives and full-blown anaphylaxis.
Fortunately, this is fairly straightforward because there are some foods that are known to be high in histamine – avoid them and you reduce the total load of histamine in your body. The foods with the highest concentration of histamine are:
In addition to these, while they aren’t high in histamine themselves, bananas are known to hold histamine in the system so we may consider avoiding them as well.
One of the ways we treat allergic reactions is to take an anti-histamine such as Benadryl (diphenhydramine). Another way is to improve the metabolism and clearance of histamine. However, if you have a genetic mutation that affects your ability to do this, then histamine will stay in your body longer and increase the severity of an anaphylactic food reaction.
Naturopathic physicians put patients on low histamine diets all the time for other inflammatory conditions, so what if we did the same for our anaphylactic patients? Would that decrease the severity of their overall food reactions? Well, possibly.
As a Naturopath I look to help reduce the inflammatory response, adjust the diet, and improve a healthy digestion in all my patients. These principles can help reduce the overall inflammatory response and could play a role in helping to reduce the severity of food reactions. By understanding how the reactions occur we may reduce the intensity of food reactions.
As we begin to look deeper and continue to explore the role of genetics and immune system regulation in food allergies we may start to find ways of reducing the severity of anaphylactic allergic reactions. I think there is more to learn about the regulation of IgE and how we can help stabilize mast cells. There is also a clear need for further research into mast cell activation disorder as a possible underlying cause of food allergies.
If you are interested in testing your IgE levels, or you (or someone you know) struggle with food allergies, you can find lots of information on this website – please feel free to browse. In particular, I invite you check out my two special food allergy services designed specifically for adults and children respectively. If you wish to make an appointment with me to discuss your health concerns you can do so using the book online tool above. Don’t worry if you don’t live in the Issaquah, Washington area, I do phone and Skype appointments as well as in-person appointments.
Join me next time for more information on food allergies.