Question: Are allergies formed at birth or do they develop over time before you become allergic to that certain product?

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  1. that’s a great question ambibambi. I’m not an immunologist, which would be the best person to talk to, but I know that there is often a genetic contribution to allergies. Scientists have shown that peanut allergies tend to run in families. If you have a close relative with a peanut allergy, your risk of being allergic to peanuts is 7%. If you don’t, then your risk is only 0.5%.

    64% of Identical twins (which share the same DNA) shared the same allergies, so there is definitely a genetic link. Which specific genes are important isn’t yet known. Clearly they will have to do with the immune system but we just don’t know which are the important ones yet. But we do know that genes are not the whole story. If they were, then if one identical twin was allergic to peanuts, the other one would always be allergic too. Because they have the exact same genes.

    The fact that in 36% of the cases this wasn’t true suggests that the environment plays a role too. Recent studies show that sometimes the mother eating allergens increases the risk of the baby being allergic, but not massively. others show that parents are becoming increasingly paranoid about exposing their children to strong allergens like peanuts and avoiding giving them until they are much older, like 5 or 6. many are doing it in a doctors office. the research suggests that by failing to expose children to these allergens early enough means it shocks their system more, and results in an increased rate of children with allergies.

    These studies are not conclusive, and there is still much to learn about this still.


  2. There is definitely a lot of unanswered questions about allergies that people are working hard to answer. There is definitely evidence of a genetic link as Miranda has mentioned, but you can also develop an allergic response to some allergens as an adult. For example, people who work in mines and are constantly exposed to dust (if they are not wearing proper safety equipment) and develop an allergic response similar to asthma. Allergy is a complex disease and results from multiple genetic and environmental factors. So it takes a lot of time and work to understand how all these factors come together to end up as an allergy.

    We know that there are two main parts to allergy. One is that our immune cells amount a response where we have been exposed to the allergen, this is called inflammation. People with allergies have trouble turning inflammation off when we don’t need it anymore. The other part is the cells which form a barrier to protect us, like our skin cells which cover us or the cells which line our airways are normally stuck together really tightly to prevent allergens getting in. In people with allergy the cells don’t stick together quite as well and it is easier for allergens to get inside. Learning how important these barrier cells are in allergy is only recent, perhaps the last ten years, so there is still a lot to learn about their full role in allergy.



  1. Thanks!


  2. Very good question amber