It seems the more advanced our society becomes and the cleaner we get, the more prevalent food and other allergies become.

The occurrences of common allergies are much higher in more developed countries than in their lesser developed counter parts. And the numbers are increasing as industrialization spreads through out the world.

According to the hygiene hypothesis, the modern methods of cleaning and sanitizing get rid of too many germs. The body's natural immune system doesn't have enough to do.

In children, it doesn't develop the way it should. And since allergies are an incorrect response of the immune system, childhood and adult allergies have become more prevalent.

Studies also show that common allergic diseases like hay fever, eczema and food allergies are found less often in children from large families.

Apparently being exposed to infectious agents (germs) by brothers and sisters is a good thing. It helps the immune system learn what it's supposed to protect our bodies from.

Antibiotic usage during a baby's first year and the growing use of antibacterial cleaning products has also been linked to an increase in asthma and other allergies.

The hygiene hypothesis explains that the antibacterial cleaning products and antibiotic drugs limit our immune system's exposure to infectious diseases, parasites and other bacteria.

This limits the immune systems development. Because of the lack of dirt and germs, the immune system doesn't learn what it's supposed to be protecting the body from and goes after the wrong things.
