Food allergies are on the rise. In the US, more than 10% of the adult population has an allergy to peanuts, shellfish, dairy or other foods. In the UK, hospital admissions for food allergies have increased fivefold over the last 30 years. In Italy they have tripled in the last 40 years, led by lactose intolerance.
Luckily, we're building the arsenal needed to reverse this trend so that one day food allergies will be a thing of the past. First, however, a very quick recap.
Food allergies, an instant journey
The most common types of food allergies are triggered by antibodies called immunoglobulin E or IgE. These antibodies were discovered in the mid-60s and kicked off an era of food allergy research that continues today. The early findings have spawned thousands of studies: They paint an intricate picture of how food allergies work, suggesting ways we can prevent and treat them.
When someone has food allergies, IgE immunoglobulins are involved in activating an immune system response to that specific food. Essentially, the body sees that food as an enemy, releasing histamine and other inflammatory chemicals to fight it. This causes symptoms ranging from itching and sneezing to wheezing and anaphylactic shock. The result can be anything from a minor inconvenience to death.
We have yet to fully understand why the body sometimes sees harmless substances this way, but we now know a lot more about how to prevent this process from happening.
Prevention is better than cure
The old saying also applies to food allergies. The small rules of doctors that bring benefits are concentrated in a few cornerstones: yes diet, no dirt, yes dogs, no dry skin, beware of detergents, yes vitamin D. Studies have found that people have a lower risk of developing food allergies when they have sufficient levels of vitamin D, diet, live with a dog in the house, avoid dry skin, and are not obsessive with cleanliness. Above all, avoid too aggressive detergents. All elements that contribute to the development of a good microbiome.
There is also evidence to suggest that when children consume potentially allergenic foods early in life, this trains the immune system to accept them. Clearly, for many people who suffer from food allergies, prevention early in life is no longer an option. However, other approaches are taking shape.
Immunotherapies
Most food allergy interventions currently target the immune system in an attempt to retrain its response to allergens. The "knights" who fight them are today essentially 3:
One technique, known as immunotherapy with allergens, involves slowly building exposure to a problematic food. Starting in very small doses, the body slowly gets used to no longer seeing it as a threat. People with reactions to peanuts, eggs, milk, or even multiple foods have found success using this method. However, immunotherapy requires regular exposure to allergens which, as mentioned, can cause side effects.
Then they exist anti-IgE drugs which can block the antibodies involved and raise the threshold for a particular allergen before it makes you sick. A lot of water has passed under the bridge since the discovery at Stanford, in 2013, of one of the first anti-Ige molecules (I talked about it here). Drugs of this type may be especially helpful when combined with allergen immunotherapy to desensitize people to troublesome ingredients.
I allergy vaccines are another option. These work by reshaping the body's immune response to a particular food so that it does not end in disease. An example? The vaccine against food allergies caused by peanuts. The most advanced are in a single dose, and contain a pool of allergens linked to an enzyme. Even patients positive for more than one allergen can be treated at once.
