Scientists are trying to engineer apples so that the most widely consumed fruit in Europe no longer triggers allergic reactions. But would people want to eat them?
Peanut, egg and soy are more common food known to trigger an allergic reaction, a problem affecting around 8% of children in the EU. Intuitively, you might not list apples as causing allergic reactions. But in fact 75% of people allergic to birch pollen are also allergic to apples. This happens because a protein in the pollen, which causes an allergic reaction, is similar to a protein found in apples and some other fruit and vegetables. The issue is more common in regions with many birch trees, such as central and northern Europe.
This kind of allergies are not easy to identify. "Some people who are allergic may simply say they don't like apples, since they've a very mild reaction after eating them," explains Eric van de Weg, plant scientist at Wageningen University in the Netherlands, "but others will suffer blistering, problems catching their breadth and swollen lips, tongue and throat." He is among a group of scientists in Europe working to develop new non-allergenic fruit. "We wanted to increase the low availability of hypo-allergenic fruit but also come to a better understanding of the genes and proteins involved," van de Weg says. One solution, tried in a previous European project called ISAFRUIT, was to genetically modify apples.
This was done by gene silencing—designed to produce a genetically modified (GM) fruit. Scientists hunted out the proteins which caused the allergic reactions and then switched off the genes responsible. Though van de Weg used some fungal genetic material for the initial apple experiments, he believes the genes could be switched off using apple genetics only, without involving any other species in the genetic engineering process. "When you silence a gene you are not making any new protein, so this means the risks are lower," van de Weg adds.
Risks of producing GM apples may be limited, but a focus group study under another part of the ISAFRUIT project in four European countries showed that the idea of genetically modified fruit provoked heated debate. And it was uncertain if non-allergenic GM apples would be acceptable to consumers. The reduction of allergens in the food chain is extremely important, according to Lynn Frewer, an expert in risk communication inNewcastle University, UK. However, studies she was involved in suggested that non-allergenic apples may not open the door to GM fruits in our supermarkets. "Although consumers - and in particular food-allergic consumers - were more positive about the [GM] apple, there was still a clear preference for traditional breeding methods applied to the same end if possible, even for food allergic consumers," she recalls.