As consumers, we could be forgiven for believing that a ‘gluten-free’ or ‘dairy-free’ label on a product means that there is no gluten or cow’s milk in that product. However, this is not necessarily the case. Many products do still contain some level of gluten, cow’s milk or whatever the allergen may be. Although the vast majority of people will not react to very low levels, depending on their sensitivity, some will.
Indeed, ultra-sensitive allergy sufferers can react to a tiny protein fraction carried in fish vapour or peanut dust. Some FM readers have proved to their own satisfaction that they react to soya residues in the flesh of soya-fed chicken even though standard laboratory tests cannot detect them – see below.
‘One would think,’ says Richard Fielder of Tepnel Biosystems, one of the UK’s leading test laboratories ‘that measuring the allergen level in foods would be a prerequisite for every food manufacturer of so called free-from foods, simply to ensure they prepare food that is safe for those sensitive to that allergen.’
‘However, testing the allergen level is only deemed necessary if the manufacturers’ own risk analysis of their product and process deems it to be so. Current allergen labelling regulations in the USA and Europe (FALCPA 2004 and Directive 2003/89/EC respectively) only require declarations of ingredients.’
Responsible free-from manufacturers obviously do deem it to be necessary and testing
becomes an integral, and expensive, part of their operation.
The 2005 labelling regulations require manufacturers to list on the pack any of the 12 major allergens which are intentionally included in the product. However, they do not specify how low the level of an allergen needs to be for a ‘free-from’ claim to be made – although recent changes to Codex Alimentarius, (see below) have at least established an accepted level for gluten (20 parts per million) for a product to claim to be gluten-free. Manufacturers working in other areas have had to set standards for themselves.
Bells of Lazonby, for example, manufacturers of the OK Foods and Village Bakery ranges, aim for 5 parts per million (ppm) for gluten with an absolute maximum of 20ppm, 2.5ppm of dairy proteins (as low as can be tested) and 70ppm of lactose.
Codex Alimentarius is a series of food standards and related texts that aim to provide a high level of consumer protection and fair practice in the international trade of food and agricultural products. It is sponsored by the the Food and Agriculture Organisation and the World Health Organisation; membership is open to all 160 member countries.
The Food Standards Agency (www.food.gov.uk 0207 276 8164) represents the UK.
Soya in chicken
Readers will remember that in the November Foods Matter (p17) and on the FM website, Tracy Smith, Jacqui Broadway and Julie Rogers all reported that, being ultra-sensitive to soya, they reacted to chickens and eggs that had been fed a soya diet throughout their lives although they could tolerate organic chickens which had only been fed soya before slaughter.
Professor Jonathan Brostoff said that this was an area in which very little work had been done; the laboratories we consulted said that they thought it was very unlikely that any soya residues would remain in the flesh.
Jacqui Broadway decided to test this out and sent a piece of
organic chicken to be analysed using the ELISA method (see next page). The laboratory was right – the test did not detect any soya. We then sent a piece of ‘normal' chicken, which had presumably been fed soya all its life, for DNA testing – but with no more positive a result.
But the fact remains that three of our readers (and how many other people) who are proven to be soya sensitive, become ill after eating chickens or eggs that have been fed a diet high in soya and do not after eating chickens fed a diet very low in soya.
Are they imagining their symptoms? Or are the tests currently available simple not sensitive or sophisticated enough to pick up the soya residues to which they are reacting?
How are ‘free-from’ levels measured and tested?
Until recently this has varied from one country to another, confusing the issue when it comes to the consumption of products from abroad.
In the UK, we measure ingredients such as gluten in parts per million or mg/kg. This is a complex process and significant variations can occur depending, for example (in testing for gluten) on whether you are measuring the type of gluten found in wheat as opposed to the gluten found in a different grain.
Levels are best validated in the developmental phase of a product by a specialist laboratory. However regular on-going testing of both ingredients and finished product will be required for any serious range of free-from products.
There are a number of specialist laboratories who offer those services including:
Tepnel Biosystems www.tepnel.com 01244 280202
Eurofins Scientific www.eurofins.com
Reading Scientific Services www.rssl.com 0118 986 8541
Enzyme Linked Immunosorbent Assay (ELISA) measures antibody reactions to specific proteins (allergens), is sensitive to parts per million and is the most commonly used technique.
DNA testing uses polymerase chain reactions (PCR) to amplify DNA sequences which are unique to specfic allergens. This technique is sometimes slightly more sensitive than the ELISA.
For many years the required level for a product to be declared gluten-free was 200ppm although this has long been seen as far too high a level to be safely consumed by coeliacs.
Indeed, new research by Coeliac UK has demonstrated villous changes (gut damage) at very low levels of ingestion of gluten. ‘The higher the standard, the greater the risk of exceeding a safe dose of gluten’, says Norma McGough, head of diet and health at Coeliac UK. ‘But, at 20ppm, the new Codex recommended standard for gluten-free products, a person can eat unlimited amounts of food without damage’.
‘The decision to change the Codex Standard has been debated for 13 years – far too long. Coeliac UK has worked closely with the Food Standards Agency over the past two years to provide an evidence base to move the standard on and we are
delighted with the result’, adds Sarah Sleet, chief executive of Coeliac UK.
Bert Poepping, director of molecular biology and immunology at Eurofins says: ‘Up till now there has not even been international acceptance of the 200ppm standards within the
industry, which has meant that consumers have been unable to rely on ‘free-from’ products from abroad. The new recommended standards, which are in line with common clinical research data, will provide consumers with greater certainty of safe gluten levels in their products’.
However, increasingly sophisticated testing only appears to increase the complexity of the task. To quote Richard Fielder at Tepnel:
‘Gluten is a composite of the proteins gliadin and glutenin that are found in the grain of grass related species (Triticeae) such as wheat, barley and rye. Gliadin and glutenin comprise about 80% of the protein contained in wheat grain, and they serve to nourish the developing plant during seed germination.
In bread, gliadins allow the dough to rise; and the different forms (α, β, and γ gliadins) have been associated with gluten sensitivity in sufferers. Naturally, many of the methods of analysis have focused on detecting gliadins, including the R5 method of analysis (which uses antibody technology) recently adopted by Codex as the formal (Type 1) laboratory method.
However, in 1999, glutenins were found to be immunostimulatory in coeliac disease challenging the belief held for more than 45 years that only gliadins were responsible. Since this time, there has been an accumulating body of clinical observations for the toxic damage of glutenins subunits.
The R5 methodology detects a toxic protein sequence (QQPFP) and, as a consequence, does not detect glutenins. Such is the pace of science, other methods of analysis are now required that detect and measure both gliadins and glutenins.
In 21st century food analysis, one method rarely serves the purpose for all foods (eg highly processed foods) and a choice of methods is now required. All these methods need to be calibrated to the same reference, and used by expert laboratories who understand these factors, so that food manufacturers can continually improve their controls and standards.’
For further information please contact Richard Fielder 01244 280202
More articles on free-from foods
First Published in 2008
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