Allergies Research: Many of us complain about having food allergies but very few of us actually have them.
Large studies have shown that food allergies are relatively rare, according to Dr Clare Mills, of the UK government-funded Institute of Food Research.
Up to 30 per cent of people in surveys claim to have food allergies, she told the BA Festival of Science in Norwich yesterday.
"But our best estimates are only 1 to 2 per cent of adults and 5 to 7 per cent of children suffer from a [ food] allergy."
And although there are many practitioners who claim to have cures and therapies, there are only two proven treatments, with true cures at least seven to 10 years away.
Part of the problem is food allergy is poorly understood or defined.
Food and other allergies arise when a person's immune system, which protects against infection, overreacts to harmless substances. Hay fever sufferers overreact to pollen, and peanut allergy occurs when the immune system responds to one of three proteins identified in peanuts that spark this inappropriate response.
Dr Mills drew a distinction between food allergies which involve an immune system antibody called IgE and respiratory allergies, such as asthma and hay fever, which have a different pathology.
While research into diseases such as asthma is well funded, much less funding goes into food allergy research. She described a new international study that will help provide information.
She said Europrevall would include contributions on incidence from 55 centres in 17 countries in Europe, Asia and Africa.
"This is all deriving from the fact we have a lack of a therapy. Once you are diagnosed there are no treatments aside from avoidance or rescue treatments after exposure."
Both she and another speaker, Dr Ronald van Ree of the University of Amsterdam, warned of the many people claiming to offer cures or treatments and at high cost but without any proven research.
Dr van Ree said there were two therapies being applied to non-food allergies. These include "allergen-specific immunotherapy" and IgE antibody injection.
The former involves administering high doses of the substance known to cause an allergic reaction in an individual for from three to five years as a way to diminish symptoms. The latter involves creating antibodies that destroy the IgE which triggers the inappropriate allergic response.
"What we need is to change that type of treatment for food allergies so we can do these treatments more safely and effectively," said Dr van Ree.
He also described the "hygiene hypothesis" which suggests that our much cleaner modern living environment may be causing a dramatic rise in all allergies. Studies from Bavaria and elsewhere have shown that children raised on farms - where there would be a naturally high level of microbial contamination, and given unpasteurised milk - have a nine to 10-fold reduced risk of allergies.
