Allergies On The Rise In US

May 5, 2013 By Deepa Gopal
Deepa Gopal's picture

Do you find yourself grabbing a tissue box lately? For millions in the U.S, spring is a time for runny noses, itchy eyes and hives. A recent study shows that spending a few years outside the U.S may actually protect against allergy and asthma!

The Study

Physicians at St. Luke’s-Roosevelt Hospital Center in New York City analyzed health data of over 90,000 children under the age of 17, and from different ethnicities.

They found that children born in other countries and now living in the U.S were half as likely to have immune problems compared to those born in the U.S. And the numbers are much lower if the parents are born outside the U.S too. The study also found that foreign-born children living in the US for over 10 years tend to see an increase in allergies.

Why does living in the U.S lower immunity? It turns out young children in other countries are exposed to dirt and infections on a daily basis. This helps their bodies develop an immune system that can distinguish between harmful bugs and harmless irritants such as grasses or pollen. 

Allergies Explained

Allergies are abnormal immune system reactions to things that are typically harmless to most people. Your immune system mistakenly believes that the substance is harmful to your body. Substances that cause allergic reactions, such as certain foods, dust, plant pollen, or medicines, are known as allergens.

Normally when our body encounters viruses and bacteria, it invokes a “Type 1” immune response. Here the antibodies directly kill the pathogens – such as virus, bacterium or other microorganism, and the human cells they infect. However for allergies, our body reacts with a “Type 2” response, where the body’s protective barriers are strengthened to repel the germs. 

In an attempt to protect the body, the immune system produces IgE antibodies when it encounters allergens. These antibodies then cause certain cells in the body to release chemicals into the bloodstream, one of which is histamine (pronounced his-tuh-meen). Histamine acts on the eyes, nose, throat, lungs, skin, or gastrointestinal tract and causes the symptoms of the allergic reaction.

Future exposure to the same allergen will trigger the antibody to respond again. So every time you come into contact with the allergen, you'll have an allergic reaction. Perhaps time to move to a different country for a while!!