Anyone with a child in school is probably aware of the need for peanut free zones. You get a notice when your child returns from school on the first day stating that at least one child in their class has a peanut allergy, which means nothing with peanuts gets sent to school for your child’s lunch. If you are a parent of a child with a peanut allergy you understand how important and serious this is – your child is literally one errant Snickers bar away from death.
The general consensus is that food allergies have been on the rise in developed countries, although studies show a wide range of estimates based upon study techniques. A US review found the prevalence of self-reported peanut allergies ranged from 0-2%. A European review found the average estimate to be 2.2% – around 2% is usually the figure quoted. In a direct challenge study, at age 4, 1.1% of the 1218 children were sensitized to peanuts, and 0.5% had had an allergic reaction to peanuts. That means there are millions of people with peanut allergies.
So far there is no cure for the allergies themselves. Acute attacks can be treated with epinephrine, but there are cases of children dying (through anaphylaxis) even after multiple shots. The only real treatment is to obsessively avoid contact with the food in question. Peanuts, tree nuts, and shellfish are the good most likely to cause anaphylaxis.
There is, however, a potential solution. Researchers have been working for year on developing a cultivar of peanut that does not cause allergies. Attempts to achieve this through conventional breeding and hybridization have failed and does not seem likely to succeed. The only real hope of a hypoallergenic peanut is through genetic modification. We are, in fact, on the brink of achieving this goal, but anti-GMO fears are getting in the way.
There are 7 proteins that have been identified in peanuts that cause an allergic reaction. The allergic reaction from peanuts is entirely an IgE mediated Type I hypersensitivity response. The proteins crosslink with the IgE antibodies, which them bind to mast cells and basophils (cells in the immune system) causing a significant inflammatory response that clinically causes the allergic reaction. One peanut contains about 200mg of protein, and as little as 2mg is enough to cause objective symptoms of an allergic reaction.
What makes a food protein an allergen is interesting. About 700 amino acid sequences have been identified that help confer allergenicity to protein. These protein segments allow the protein to survive processing and digestion, and allow the protein to bind to IgE antibodies.
In 2005 a study was published showing that it is possible to silence the gene for the Ara H2 protein, the primary allergenic protein in peanuts. A 2008 follow up by the same team showed decreased allergenicity of the altered peanut. So where are our hypoallergenic peanuts? This is a complicated question, and I don’t think I can give a full answer.
The delay in marketing a hypoallergenic peanut seems to be due partly to technical issues – it turns out to be a lot more difficult to make the necessary changes than at first thought. However, it also seems to be due to the anti-GMO campaign, which has been scaring away investors and making politicians gun-shy.