Clinical tolerance of processed foods.
OBJECTIVE
To review the effects of technological processing on selected foods of relevance to childhood allergy from the viewpoints of reduced allergenicity, contamination of processed foods by allergens introduced during processing, and ad hoc technologies to produce reduced hypoallergenic products.


METHODS
We searched the literature (PubMed/MEDLINE) for articles published between January 1994 and April 2004 using the following keywords: food allergy AND process* OR heat* OR cooking OR toleran*.


METHODS
We drew on our collective clinical and biological experience to restrict retrieved studies to those of more frequent relevance to a hospital allergy practice.


RESULTS
Comparatively few clinical studies address the modification of allergenicity of food through cooking or processing. Dairy foods are largely unaffected by processing and may be contaminated by, or themselves become, hidden allergens. Hypoallergenic formulas based on milk, soy, or rice and homogenized beef are successful applications of allergenicity reduction via technological processing. Egg, fish, condiments, and vegetables all carry heat-resistant allergens and should also be considered contaminants. Cereals and bakery products are generally well tolerated, but their allergenicity may be enhanced by processing; the case of rice is still open. Peanut allergens are stable, and the evidence is scant that thermal processing affects the allergenicity of soybean and soy hydrolysates. The debate is ongoing about the tolerance of vegetable oils.


CONCLUSIONS
It is too early to systematize clinical studies based on single procedures. Processing affects antigenicity, but this does not always translate into safety recommendations. Industrial processing is liable to contamination, and monitoring and labeling are industry priorities. Clinicians should evaluate foods by as complete a workup as possible before recommending processed foods.
Fiocchi
Alessandro
A
Department of Child and Maternal Medicine, University of Milan Medical School at the Melloni Hospital, Milan, Italy. allerg@tin.it
Bouygue
Gabriel R
GR
Sarratud
Teresita
T
Terracciano
Luigi
L
Martelli
Alberto
A
Restani
Patrizia
P
D000818:Animals; D002417:Cattle; D003611:Dairy Products / Q000009:adverse effects; D002523:Edible Grain / Q000276:immunology; D021181:Egg Hypersensitivity / Q000517:prevention & control; D005511:Food Handling; D005512:Food Hypersensitivity / Q000517:prevention & control*; D006801:Humans; D027845:Malus / Q000276:immunology; D008461:Meat Products / Q000009:adverse effects; D016269:Milk Hypersensitivity / Q000517:prevention & control; D017747:Seafood / Q000009:adverse effects