Cracking the peanut allergy
TechKnow investigates what’s fuelling the spike in food-related allergies and whether science can cook up a cure.
Every three minutes, a food allergy reaction sends someone to the emergency room in the US. It’s an alarming statistic that worries parents and adults across the nation. In some extreme cases, mere nanograms of peanut protein can trigger a dangerous reaction and a mad dash to the hospital.
The US Centre for Disease Control reported that from 1997 to 2011 the number of children with food allergies increased 50 percent. Over 15 million Americans suffer from food allergies, at a cost of $25bn each year.
“A hundred years ago people did have food allergies, but it wasn’t to the same epidemic proportions that we are suffering from now,” says Dr Kari Nadeau, an expert in adult and paediatric allergies and head of a special allergy research centre at Stanford University.
“People are very much living with this disabling worry of having an accidental exposure.”
Allergic reactions occur when the body’s immune system overreacts to certain proteins and food. While any food can trigger an allergic reaction, about 90 percent are caused by eight sources: milk, eggs, peanuts, tree nuts, fish, shellfish, soy and wheat. When the immune system launches a protective response, cells release antibodies known as immunoglobulin E (IgE).
“An IgE is the match that lights the fire behind the allergy, within six minutes you can have this very serious allergic attack,” Nadeau explains.
The marching order for decades has been avoidance and training children to become allergen inspectors before consuming certain foods. But, it’s very difficult to track and vet every plated meal or crumb that a child with a food allergy might come across. Accidental ingestion happens and, for some, it can be fatal.
So now, instead of avoidance, experts are looking at new ways to retrain the immune system and develop new treatments to desensitise food allergies.
At Stanford, a treatment called oral immunotherapy was effectively used for desensitising patients – one allergen at a time. But doctors faced a new problem, as a third of people the who suffer from allergies are allergic to not just one, but multiple foods.
“The minute you have a food allergy you also have a higher rate and a chance of having other food allergies too,” says Nadeau.
In 2009, the team at Stanford decided to tackle this problem head-on. The breakthrough came in a form of an IgE-suppressing asthma drug called Xolair.
According to the national Institute of Health, about 15 percent of people with food allergies also have asthma. The link between the two are the symptoms that can trigger an attack on the lungs. Since the Federal Drug Administration’s (FDA) approval in 2003, Xolair has proven effective in severe cases of asthma.
“If it’s working against IgE and we know that IgE is important in food allergy, what if we start giving it initially to people with food allergies and then we start giving them the food that they’re allergic to? Could that protective cover help us increase the ability to get children and adults to food allergens to the same level that they’d like to eat them?”
According to Nadeau out of 700 patients in the studies conducted since 2003, all who completed the trials have had positive results.
This is not the only way to tackle food allergies: Using traditional Chinese medicine, Dr Xiu-min Li has created a therapy called food allergy herbal formula two, clinically known as Fahf- 2. Studies show that herbal compounds in Fahf-2 reduce IgE levels and combat symptoms of peanut-induced anaphylaxis.
The treatment is currently in advanced clinical trials, being tested as a new botanical drug under the complementary alternative medicine arm of the FDA.
“This approach is effective to prevent reactions … we will continue to work hard to build up an even stronger tolerance,” Li explains.
Scientists still don’t know why food allergies are on the rise, but whether it’s high-tech western-style medicine or alternative eastern herbal treatments, the solutions seem to be coming into focus.