Food allergy and food sensitivity are terms which are often a point of confusion regarding the difference between the two. While both indicate an immune response and that the body is not happy, they activate slightly different areas of our immune system and create different symptoms or reactions.
Primarily an allergic reaction is an immediate to reaction of the offending food. Symptoms appear within minutes and can be life threatening. Food sensitivities and intolerances are a little sneakier and can produce non-descript symptoms (headaches, feeling yucky, gut problems) sometimes hours, if not days after eating the offending foods.
What’s going on? Why and how are they different? I hear you ask.
So, our immune systems are made up of many cells all swarming around our body looking for invading germs and gremlins to fend off. However, as within all good military forces, there are specific cells for specific jobs.
When a nasty little germ or gremlin (aka foreign body) breaks our first line of defence – which is our skin – Neutrophils are the primary response team. These guys stop the invaders from circulating, kill the bad guys by eating them, in a process called phagotosis, they can also “gas” the area by releasing super oxides to neutralise the enemy as well as signalling to other cells to join the battle.
Eosinophils arrive at the site to support their fellow immune cells and “nuke” pathogens by releasing toxins. These guys are especially effective against parasites and worms and it is thought that a high eosinophil count may also be linked to allergic reactions and why many gut protocols start with a cleansing/detoxing/anti-parasitic phase.
Other supporting units include Basophils who secrete antibodies and anticoagulants at the invasion site. This creates a heightened sensitivity including a histamine reaction and release, dilating blood vessels allowing more troops to arrive onsite quickly.
Intelligence gathering and forensic examination is conducted by Lymphocytes. These guys come in two forms T & B. B lymphocytes make antibodies (more on that later), they study the enemy closely and learn what destroys them and what just makes them cranky. All this data is stored for referencing later. Should the same pathogen breach defences again, these guys can quickly issue instructions on how to annihilate it! Our T lymphocytes have the far less glamorous, but no less import role of aiding cell-mediated immunity.
Finally, the clean-up crew is called to site. Monocytes cells including macrophages arrive at site and devour (yes really – eat) the dead, stunned, wounded or maimed cells (check out this link for live blood action of macrophages at work https://www.youtube.com/watch?v=BDr44vLNnPY – seriously cool!
So, what does all of this have to do with allergies and sensitivities you ask. Hang on I’m getting there.
Part of our immune system includes antibodies. Antibodies are a type of blood protein which are created when contact is made with specific pathogens (baddies). These guys hangout with our immune cells and identify the invading forces identifying and helping to neutralise them. Commonly this will be in relation to bacteria and virus or other unfamiliar (foreign) particles (dust, pollen, dander etc). These special ops teams also have their own military ranks with 5 different branches: IgA, IgE, IgG, IgM and IgD antibodies all partying in their way around our bodies. The roles that each of these guys have are very specific, but when looking at reactions to foods we commonly look specifically at IgA, IgE and IgG antibodies. These dudes are responsible for identifying common foods as invaders and spiking a full blown immune invasion.
Coeliac disease is an autoimmune condition where sufferers react to gluten, causing a range of health conditions. When testing for this disease Dr’s will often start with an IgA antibody test. However, this test can provide with false negatives as it has been determined that a high number of people with Coeliac’s may also have an IgA deficiency – But that’s another blog for another day.
If you are having an allergic reaction to anything, in this case, food, you will be having an IgE mediated response. This means that the IgE dudes have determined that the food you have just eaten is a serious threat to Homeland Security and needs immediate attention. These reactions often manifest with life threatening symptoms including anaphylaxis, swelling of the airways causing restricted breathing, as well as swelling on the face and or tongue. Redness is also common which is a sign of the underlying inflammatory actions occurring.
Food sensitivities are an IgG immune response. These guys place things on the watch list. They’re alert, but not alarmed. However, if consumption of reactive foods continues they will amp things up a bit, but not to the same level of food allergy. Signs of a food sensitivity can include the express exit of faecal matter (diarrhoea), constipation, bloating, headaches, brain fog, sleep disturbances, weight issues and anxiety. These symptoms can certainly make life unpleasant but do not pose a risk to life.
Fun fact: people who have known food allergies may not react to the same foods when having an (IgG) food sensitivity test. This is due to the different antibodies reacting differently to the food proteins.
Food allergies and sensitives are both caused by hyperactive and reactive immune systems, however, a food allergy is quick acting, get your attention NOW reaction and can be a life threatening. While food sensitivities or intolerances, won’t kill you but they won’t leave you feeling the best either and can have a lasting impact on your health.
Allison Faulkner is a qualified and accredited Naturopath, also holding additional qualifications in Nutritional Medicine. She runs a Naturopathy and Wellness clinic in Albion Park, NSW where she co-founded the Whole Life Wellness Programme.