What do eggs, nuts, milk, wheat, fish, shellfish and soy have in common? That’s right, they are all common allergens - these seven foods are the most common triggers of food allergy in the world and are responsible for 90% of reactions.
This list of top allergens can cause a wide variety of symptoms including nasal congestion, sneezing, a runny nose, red, itchy and watery eyes, hives, swelling, tummy pain, nausea, and diarrhoea (just to name a few). In severe cases, the body can go into an extreme reaction known as anaphylactic shock - a medical emergency that requires immediate attention.
However, not all allergens are food - some can be inhaled. Pollen, mould, dust mites, pet dander, or even cockroach faeces can all trigger allergic asthma, hay fever or other forms of allergic rhinitis. Considering that allergic asthma is the most common type of asthma that can cause shortness of breath, wheezing, coughing, and feeling a tightening sensation in their chest.
Allergy reactions are overreactions of the immune system that cause a number of tissues to swell, heat up, and become itchy, leading to tightened airways, excess mucus production, breathing difficulties and unwanted skin rashes.
What’s the difference between allergy and intolerance?
It might come as a surprise but allergies and intolerances are completely different medical problems. Whilst they can present in similar ways physically, they are caused by different reactions in the body. For example intolerances often take longer to manifest, whilst allergic reactions are often rapid reaction that can sometimes be deadly.
Allergic reactions are characterised by an overall, systemic immune reaction that the body produces in response to a foreign invader. In this type of response, the body’s disease-fighting immune cells misidentify harmless substances, flagging them as dangerous bacteria or viruses.
These “misguided” immune cells then “attack” the supposed allergen, trying to clear it from the body. They produce immune cells called IgE antibodies that bind to the “allergen” which initiates a release of histamine. Histamine one of the substances made by IgE cells but it is the one that is largely responsible for many allergy symptoms including:
- Sneezing
- Runny/stuffy nose
- Red, watery eyes
- Swelling
- Abdominal pain
- Nausea
- Diarrhoea
Allergies
Allergic symptoms often appear immediately, whilst symptoms of intolerance can take up to 20 hours to develop. This is because it takes time for the substance our body is intolerant to, to slowly move through our digestive system. Unlike allergies, food intolerances can never causes anaphylactic shock.
Food intolerances
A food intolerance, on the other hand, is when the body can’t digest the food properly or becomes “overwhelmed by it”. This can lead to digestive symptoms like bloating, cramps, constipation, or diarrhoea and in some cases, trigger severe reactions that look like an allergic response.
For example, lactose intolerance is caused by decreased production of a protein called lactase that is responsible for the breakdown of a sugar in milk called lactose. When we do produce enough of this enzymes, we can end up with unwanted symptoms due to residual lactose moving through our gut. Enzyme deficiencies can be innate or acquired, meaning they can be the result of genetic variation or the health of our gut microbiome and gastrointestinal tract.
FUN FACT: Most infants can digest milk, but our production of lactase ceases to be produced as we journey our of early childhood. Perhaps this is nature's way of reserving breast milk for growing bodies who need it most?
The Connection Between Food Intolerances & Allergies
Both food intolerances and allergies can be mediated by the health of our gut microbiome. Research has shown that microbiome diversity and richness - or rather, having an abundance of different good bugs in your gut - helps to prevent allergy and potentially ward off unwanted misguided Ige immune activity.
Food intolerances, on the other hand, can be due to an inability to break down a certain substance in food food or the presence of certain bacteria in the gut that ferment carbohydrates. For example, the latter is true for FODMAP intolerances. Those that feel better eating less of these fermentable forms of carbohydrates are thought to have more microbes that can eat these carbohydrates in their gut. This can lead to the development of excess gas production, bloating, diarrhoea and constipation. Like all intolerances, FODMAP intolerance is not an immune reaction but rather an inability for our body to tolerate certain food substances.
When to seek advice?
Whilst completely different reactions, food allergies and intolerances are dependent on the health of our gut microbiome. It can be tricky to cipher off what type of reaction you have and seeking out professional guidance is always advised. From what we know of the microbiome to date, diversity of food is the key to fostering good gut health long term. It is possible to make your gut health or the health of a family memeber worse by cutting out foods certain foods that appear to cause a reaction. This is why working with a professional is the best place to start when figuring out your unique response to food or when trying to help a child with food allergies and intolerances.
Book in for a free clinic discovery call to learn more on how our clinic can support intolerances and allergies.
