Explain the old friends hypothesis and how it relates to child health.

Question

What will be an ideal response?

Answer 1

Ans: One proposed explanation for the increase in allergic diseases, including asthma, in recent years is the old friends hypothesis which says that starting at birth the human immune system receives inputs from the environment that prepare it for the microorganisms it will encounter. In contemporary society, children are exposed to fewer of these microorganisms and if these inputs are inadequate or inappropriate, the system may later react to harmless substances such as pollen, dust, or food allergens in a way that is similar to how it reacts to harmful organisms, resulting in the allergic conditions so widely seen today (Bloomfield et al., 2016). The idea that early exposure to a wide range of harmless organisms helps to strengthen the immune system comes from research showing that having more siblings (Penders et al., 2014); growing up in the farm environment (von Mutius & Vercelli, 2010); or living with domestic pets (Ownby, Johnson, & Peterson, 2002) lowers a child’s future risk of allergic diseases.