Allergies, sensitivities, and intolerances are fast, becoming chronic conditions in Australia. Some estimates suggest up to 20% of the population may have a food intolerance or food allergy. Common symptoms of intolerances and allergies include hay fever, allergic rhinitis, digestive disorders such as reflux, bloating, excess gas, and dysbiosis, eczema and asthma, to the more life-threatening severe anaphylaxis reactions. As humans, we are exposed to an array of foreign bodies or substances via the gastrointestinal tract, respiratory system and the skin. Each individual’s immune system interacts with and acknowledges these substances in a variety of ways, creating situations ranging from no reaction to a severe anaphylactic reaction, and anywhere in between.
Allergies occur when the immune system reacts to some of the proteins in the allergens. Food allergens include wheat, gluten, milk protein, egg, lactose, nuts, seafood, and strawberries. This list is increasing all the time. An allergic reaction involves a complex interplay between antigens, immune cells (e.g. T cells, Immunoglobulin E (IgE), Immunoglobulin G (IgG), Immunoglobulin A (IgA) antibodies) and effector cell activation (mast cells, basophils, eosinophils). The reaction from these cells results in an inflammatory response, with localised and systemic symptoms. Allergies can lead to sustained inflammation which then may act as a potential driver exacerbating other chronic health conditions.
An Intolerance is considered a ‘chemical’ reaction to a substance, usually a food protein, and does not show up on a traditional allergy test. Possible symptoms of food intolerances and sensitivities include fatigue, headaches, anxiety, skin complaints, gastrointestinal symptoms, migraine, depression, joint and muscle pain.
Food sensitivity is usually a delayed reaction to a food or substance that is milder than symptoms of intolerance or allergy.
What can cause food intolerances or sensitivities?
Differing immunological response to a common harmless substance is why one person reacts to a potential allergen, and another person doesn’t. The failure of the immune system to determine friend from foe can result in a loss of immune tolerance and subsequent reactivity. There are several possible causes of food intolerances and sensitives, with many related to the gastrointestinal tract and digestive function. A reduced digestive function can occur due to low gastric acid, and inadequate enzyme secretion from the small intestine and pancreas. An insufficient digestive function can cause an intolerance due to food components remaining too big and not being adequately absorbed in the correct regions of the gastrointestinal tract. Medications that suppress gastric acid can also affect digestive function.
The gastrointestinal tract and immunity
New research has found a close connection between the immune system and the integrity of the gastrointestinal tract with round 70% of the immune system located in the digestive tract. The exposure to food antigens can trigger rapid gut inflammation leading to barrier hyperpermeability, sometimes termed ‘leaky gut’. The gut flora (microbiome) plays a vital role in the protection from a food allergins by improving mucosal barrier function. Understanding the causes of the intolerances is essential to determine the most appropriate treatment approach.
Treatment approaches for intolerances and sensitivities
The usual treatment is to avoid the suspected allergen with a specific diet (low FODMAPS, gluten and dairy-free, e.g.) to relieve symptoms. However, avoidance of food allergens can be a double-edged sword. Highly restrictive diets that eliminate several foods are generally not recommended in the long run due to the risk of nutritional deficiencies and social unacceptability.
Support of both the gastrointestinal tract and immune system is central to providing a more reliable and long-term solution to allergic conditions. Addressing the factors that influence tolerance combined with therapeutic elimination and gradual re-introduction of intolerant foods provides the potential to decrease the frequency and intensity of the allergic response.
The process of understanding what the problem is, and how to make changes to get results can be complicated. We aim to help with this complex process to find solutions to help you feel better.