Allergies are on the rise, especially in developed countries where the goal of cleaning and sterilizing the living environment has reached hysterical levels.

In lieu of this fact, health experts have are aware that children who grow up on farms seem less prone to allergies, and one long-standing theory that attempted to explain this was that exposure to dirt at an early age helps to strengthen a person's immune system.

Now, new research has shed further light on this phenomenon, and what it has revealed is that a substance found in dust might be responsible for reducing a child's incidence of allergies and asthma. The specific substance in question is a sugar molecule known as arabinogalactan.

It has been theorized that when children inhale high concentrations of arabinogalactan during the first year of their life, it affects their immune system in a way that tempers any excessive systemic reactions to allergens. Arabinogalactan is often present in large quantities in certain plants used as forage crops.

The findings, published in the Journal of Allergy and Clinical Immunology, lend some insight into why children raised in agrarian environments suffer less frequently from allergies. To gain a better understanding of the physiological impact of arabinogalactan, researchers used animal models to test its effects on the immune system.

At the cellular level, special cells that alert the immune system to invaders, known as dendritic cells, respond differently in the presence of arabinogalactan and instead acted to suppress the immune reaction, though specifically to arabinogalactan. The immune response to other pathogenic invaders remained functionally intact. The mechanism is similar to the one by which certain bacteria alter the body's immune reaction to their presence.

It is not surprising that a component of grass might actually protect people from hay fever. It may simply boil down to levels of exposure, whereby high doses early in life can confer protection, while low levels may induce allergic reactions. In fact, the process of adapting to a person to allergens involves exposing them to gradually increasing doses of the offending material in the hopes that the allergic reactions will eventually lessen or disappear, a process known as hyposensitization.

The next step would be to determine if arabinogalactan can be utilized as a treatment or prophylaxis for allergies and asthma. This may entail formulating the sugar into an aerosol spray or drops to be administered directly into the nasal cavity.

If you have questions or concerns about your child's allergies, speak with your pediatrician. For more information about allergies, visit Kid's Health and the website for the U.S. National Library of Medicine, a division of the National Institutes of Health (NIH).