Naturally, people are advised to keep their home spotlessly clean, especially if they have a baby or small children. But here’s the catch. A study by Brigham and Women’s Hospital demonstrated that early exposure to some of these pathogens may actually help to build up the immune system, offering resistance to asthma and other allergies¹.

Some medical experts have theorized that your house can actually be too clean², especially as it relates to babies and young children. They have named this theory the “hygiene hypothesis.”³ Early contact with asthma- and allergy-causing microbes —including common bacteria—may prevent the release of histamines that lead to sneezing, coughing, wheezing and clogged airways. Histamines are the immune system’s response to allergens. In fact, a study by the scientists at Johns Hopkins Children’s Center and other institutions found that infants who were exposed in their first year of life to pet dander, roach allergens and a variety of household bacteria seem to suffer less from allergies, wheezing and asthma.⁴

Also, it may be important for youngsters to get outside of the home and socialize. Babies aged two months and older who come into contact with other children at an early age, including older siblings, are also less prone to allergies.⁵

Children in daycare in the first year of their lives are approximately 35 percent less likely to develop allergies, according to a study of 900 infants.

City or Country?

Which one is better: a home in the city or a home in the country? It seems that both are on equal playing ground when it comes to early exposure to the elements.

For example, studies show that children who grew up on farms with continued exposure to plants, crops and animals were less likely than their urban counterparts to develop asthma, eczema, hay fever and pollen allergies.⁶ Another study of 1,300 children in New Zealand shows that babies born to mothers living on farms during pregnancy have demonstrated even more resistance to allergies.⁷ Researchers concluded that while prenatal farm exposure may protect against asthma and allergy, exposing children later in life to a farm environment might be necessary to maximize protection.

Oppositely, children raised in inner cities who were exposed to cockroaches, other pests, and animal droppings showed a low rate of asthma and allergy problems. This finding surprised researchers. (Other environmental conditions had to be considered as well, including air pollution and exposure to smoke.)

Tackling the Cleaning Conundrum

Like many people, you may think diligent cleaning is a good way to tackle allergens. However, did you know that products used for house cleaning, such as aerosol sprays, bleach and ammonia based cleaners, may also trigger allergic reactions? In fact, adults who work with spray cleaning products on a daily basis often develop asthma and other allergies. So, you’re better off choosing environmentally-friendly cleaning products.

Use common sense when cleaning. You do not want excessive dirt, dust, mold and animal hair to build up in your home. Your HVAC system still needs filters. Mold and mildew can harm wood and other surfaces. Insects and rodents can spread diseases.

The bottom line: When it comes to your living environment, you decide where and how you want to clean based on your personal preferences and environment. Just remember, a little dust won’t hurt, and it may help babies and children under three build up immunities to some allergens.