Wheat and gluten allergen testing
Why do I need to do wheat or gluten allergen testing?
Food allergies pose a widespread public health challenge, impacting millions of consumers globally. In recent years the management of allergens has gained significant attention, due to increasingly stringent allergen labelling regulations, GFSI food safety standard requirements, and the growing prevalence of undeclared allergens at the root of product recalls.
There are various reasons to test for the presence of wheat or gluten, including but not limited to:
- Supporting wheat- and gluten-free claims
- Checking for accidental contamination
- Validating and verifying gluten and wheat cross-contact management controls
Who is affected when they consume wheat and gluten?
The ‘significant cereal’ group, also called ‘gluten-containing’ cereals in some regions, describes the edible seeds of wheat, rye, barley, oats, and their crossbred hybrids. They contain proteins that trigger adverse reactions in sensitised individuals.
Wheat is a major allergen, meaning it triggers allergic reactions in a significant number of individuals. It contains proteins such as gluten, which is a combination of glutenin and gliadin that can cause a reaction. Additionally, other specific wheat proteins such as albumins and globulins can also cause an allergic reaction.
Wheat allergies are an immune-mediated reaction to wheat proteins, and the onset of symptoms is normally acute (i.e. rapid onset). Even minute amounts of the wheat present in a product can cause an allergic reaction, and symptoms range from mild skin, gastrointestinal or respiratory symptoms to potentially life-threatening anaphylaxis in severe cases. Individuals with wheat allergies must follow a strict wheat-free diet to avoid a reaction. Although rye, barley and oats can also trigger allergic reactions, they do so in a less significant number of consumers.
Gluten is the collective name for the storage proteins found in the endosperm of wheat, rye, barley and oats; it plays a functional and key role in the structural properties of baked goods, such as bread and pasta. It is a protein that consists of two linked protein subunits, glutelins and prolamins. The prolamins found in wheat (gliadin), rye (secalin) and barley (hordein) are rich in proline and glutamine amino acids, while avenin (oats) contains smaller amounts. Although these proteins are all different, they contain both individual and common immunoreactive epitopes (parts of the protein that bind with specific antibodies, triggering an adverse reaction). Some epitopes trigger allergic reactions, and others Coeliac Disease (CD). Avenin seems to be different, in that it is tolerated by most CD patients.
Coeliac disease (CD), also called celiac disease, is a lifelong autoimmune systemic disorder, triggered by gluten, that leads to the progressive deterioration of the lining of the small intestine. Individuals with classic CD present signs and symptoms of food malabsorption (diarrhoea, abdominal pain, bloating, wind, distension, weight loss and growth failure). In non-classic CD, non-specific signs and symptoms (iron deficiency anaemia, osteoporosis, fatigue) or even asymptomatic presentation are now considered to be common. The safe limit for gluten intake varies from patient to patient. For a long time it was considered to be 10 to 100mg/day, although a later study has indicated that the upper limit should be no more than 50mg/day. As gluten is present in wheat, rye and barley cereals, they all present a risk to gluten-affected individuals.
Non-coeliac wheat sensitivity (NCWS), also called non-coeliac gluten sensitivity, is difficult to diagnose; its exact aetiology (cause) is broadly unknown, and its relationship with other disorders such as IBS is murky. NCWS symptoms include IBS-like intestinal and extra-intestinal manifestations (lethargy, fatigue, skin rash, gynaecological troubles, headache, joint and muscle pain, leg or arm numbness, anaemia, depression, anxiety, psychosis), which start a few hours or days after exposure to wheat gluten and resolve when wheat and gluten are removed from the diet. An NCWS diagnosis is only proposed when other conditions such as CD, wheat allergies, autoimmune conditions, lactose and fructose intolerance, inflammatory bowel disease and pancreatic insufficiency have been excluded.
To reiterate: wheat contains many proteins. Some proteins trigger wheat-allergic reactions, while gluten (one of the proteins in wheat) triggers CD symptoms in genetically susceptible individuals. Individuals with wheat allergies need to avoid only wheat; those with CD should avoid wheat, rye and barley, and in some instances, oats.
What do the regulations require?
The popularity of (especially) gluten-free products has risen sharply in the last decade. Multiple countries, including South Africa, have established prerequisites for wheat- and gluten-free food labelling that include tolerance standards for gluten-related claims, making accurate and sensitive analytical methods imperative.
The significant cereals group, also called gluten-containing cereals, is a regulated allergen in most regions, and one of South Africa’s eight regulated common allergens; this means it must be declared on foodstuff packaging, and cross-contact in a food-producing facility must be controlled.
If you make a wheat-free and gluten-free claim, testing is required to substantiate the claim. Gluten-free products must contain less than 20mg gluten per kg of product, while wheat-free products may not contain any detectable wheat.
Does FACTS offer wheat and gluten allergen testing?
FACTS offers SANAS-accredited wheat and gluten allergen testing. View and download our testing catalogue, or contact us if you would like more information about the methods used.
All methods can be performed on surface swabs and air plates. It is important to note that all swab results are qualitative, and that the lab is accredited for select swab analyses. For more information on the FACTS laboratory accreditation status, view our SANAS accreditation certificate or contact us for more information.
Other articles and resources you may be interested in:
Part 1: Wheat vs Gluten – Medical Perspective
Part 2: Wheat vs Gluten – Regulatory Perspective
Part 3: Wheat vs Gluten – Testing Perspective
Part 4: Wheat vs Gluten – Hydrolysed Gluten: Health Risk?
Allergen labelling: Significant impact on product sales and market
Video | Wheat vs Gluten
South Africa’s regulated common allergens
To claim or not to claim – The ‘Allergen-free’ controversy
Do you have to test for all food label claims?
Testing Catalogue
Infographic: Allergen Labelling