Genetic and environmental risk factors for the development of food allergy.
OBJECTIVE
To review recent clinical and experimental studies of genetic and environmental risk factors for the development of food allergy.


RESULTS
It may be true, although it is yet to be shown, that food allergies in early childhood are becoming more common and that the causes are the same as for later-developing respiratory allergies. The mother not only transfers 50% of her genes to her baby, but she is also the exclusive environment during gestation and continues to be a major environmental factor while breast-feeding her infant. Non-genetic maternal influences increasing the likelihood of food allergy include Caesarian section and high maternal age. Allergy to sesame seems to be increasing in children. This is possibly a consequence of increased use in processed foods. The search for dietary risk factors is not limited to allergenic foods, but may include other nutrients, for example excessive intake of vitamins. Two meta-analyses have seriously questioned the use of special infant formulas for allergy prevention. Novel prevention strategies, such as probiotic bacteria, have yet to be documented further.


CONCLUSIONS
The causes of food allergy are still unknown and no particular genes associated particularly with food allergy have been identified, although there is a strong association in general between genetic susceptibility to food allergy and that to IgE-mediated allergy. There are still no measures for general recommendation in order to prevent food allergy and no genes have been linked conclusively to disease. Further research concentrating on food allergy is obviously needed.
Björkstén
Bengt
B
Institute of Environmental Medicine, Karolinska Institutet, S 171 77 Stockholm, Sweden. bengt.bjorksten@cfa.ki.se
D002585:Cesarean Section; D002675:Child, Preschool; D004781:Environmental Exposure; D005512:Food Hypersensitivity / Q000209:etiology* / Q000235:genetics* / Q000276:immunology; D020022:Genetic Predisposition to Disease; D006801:Humans; D007223:Infant; D041943:Infant Formula; D008423:Maternal Age; D008895:Milk, Human; D012307:Risk Factors