Common food allergens include dairy products, soy, peanuts, tree nuts, sesame, fish, shellfish and eggs. The effects in sufferers range from mild abdominal discomfort to death from anaphylaxis.
Proteins from food allergens may now added to food and beverage products to given them extra nutritional or functional properties, but their appearance might be changed and consumers might not expect them to be there.
For their study, accepted for publication in the journal Allergy, Asthma and Clinical Immunology, Rohan Ameratunga and SeeTarm Woon investigated a functional flavoured water marketed in New Zealand in 2009. Called Whole, the beverage contained isolated bovine whey proteins; a process called Clearprotein rendered these proteins clear, rather than cloudy as would normally be expected for dairy ingredients.
The beverage was marketed as ‘a bridge for the hunger gap’ and the presence of dairy proteins was noted on the front of the bottle in 3mm font, in accordance with New Zealand regulations.
However two children with allergies to cow’s milk, aged 18 months and 9 years, suffered anaphylaxis after drinking the product.
Ameratunga and Woon conducted studies to establish the concentration of beta-lactoglobulin, the most abundant protein in cow’s milk which is absent from human breast milk, in the Whole product. Western blotting and ImmunoCAP inhibition studies were also conducted.
They found that the beta-lactoglobulin content was around 3g/l, that is three-times that of cow’s milk, leading them to call Whole a ‘hyperallergenic’ product.
“Hyperallergenic foods would… be expected to cause more severe reactions for a given weight/volume than the food of origin,” they wrote.
They also noted that the severity of the allergic reaction depends of several factors including the quantity consumed, the level of food-specific IgE antibodies, and co-factors like exercise. The 18 month-old child consumed a smaller amount of the product than the 9 year-old, but her reaction was stronger.
Need to name
A spokesperson for the Anaphylaxis Campaign in the UK agreed that the increasing use of proteins is a growing problem. “It is an issue and a major concern. People do check labels, but sometimes complacency sets it.”
She referred to a case in the UK where a child died after consuming a fruit beverage containing dairy proteins; their mother had scanned the ingredients list but did not spot the dairy ingredient as she was not expecting them to be there.
The spokesperson pointed to guidelines from the UK’s Food Standards Agency, which suggest that proteins not be added to a formulation unless they are absolutely necessary – and if they are that they should be reflected in the product’s name.
Fonterra, the maker of the Whole product, was sent a copy of Ameratunga and Woon’s study pre-publication.
It is now advising international customers that use dairy proteins it supplies to clearly identify the dairy content.
Fonterra said it is advising international customers of the potential need to identify the dairy content of foods containing specialised dairy proteins, following the publication of a new academic study.
Fonterra produces specialised dairy proteins used as ingredients by international food companies.
Chief technology officer, Jeremy Hill, said “specialised dairy proteins have been used for years and are recognised as safe for consumers”.
However he agreed that consumers may not think they are in products that do not look like dairy.
“When the allergic reactions were brought to our attention, we put a comprehensive plan in place, working with Allergy New Zealand, to alert the community about Whole’s dairy protein content,” said Dr Hill.
“Although Whole fully complied with New Zealand Food Safety Authority requirements, we also changed the labelling to more prominently state that the product contained dairy,”
“We have learned from this experience and we can all do better to minimise the risks in the future.”
Whole was removed from the market in April 2010. The company says this was due to poor sales.
Allergy, Asthma and Clinical Immunology 2010, 6:33
Anaphylaxis to hyperallergenic functional foods
Authors: Rohan Ameratunga and SeeTarm Woon