Allergies: blessings in disguise for cancer prevention?

Those of us who suffer from them know the symptoms – runny eyes and nose, coughing, and itching. I am talking about allergies. Some of us are allergic to food, some to particles in the air such as dust and pollen, some to certain chemicals.

Well, actually the miseries of allergies may be worthwhile trade offs to cancer prevention. Researchers at Cornell University reported in a recent study that allergic reactions can actually provide protection from certain types of cancer which “involve organs that interface directly with the external environment.” These include skin, colon, bladder, mouth, throat, uterus and cervix, lung and gastrointestinal tract cancers.

According to lead researcher Paul Sherman

“The study revealed a strong relationship between allergies and cancer in environmentally exposed tissues…This relationship seldom exists between allergies and cancers of tissues that are not directly exposed to the environment, such as cancers of the breast and prostate, as well as myelocytic leukemia and myeloma.”

The study results are based on an analysis of a database of 646 studies on allergies and cancers which were published during the last 50 years,

Interestingly, certain allergies are more strongly linked to the above listed cancers than others. Environmental allergies such as eczema, hives, hay fever, and animal and food allergies are the ones most strongly associated with lower rates of the said cancers.

The mechanism behind the cancer preventive properties of allergies may be explained by the fact that allergies help block foreign particles from entering the body, particles which may be carcinogenic or may contain carcinogens and other toxic substances.

There are some exceptions to this allergy-cancer inverse association. Asthma, which is a form of respiratory allergy, is associated with higher rates of lung cancer. Glioma and pancreatic cancer are cancers of internal tissues but are still linked to certain allergies. However, asthma is an exception since unlike other allergies, it reduces the ability to get rid of mucus. Glia (a type of brain cells) and pancreatic cells do get in contact with the environmental indirectly through the olfactory and digestive tracts, respectively.

Allergies have been erroneously thought of as disorders of the immune system. In fact, allergies are the front line of defence against certain invaders in the environment, be they parasites or carcinogens. So next time you feel the allergic reaction coming, maybe you should thank your lucky stars instead of complain.

The next question is, how do medications that we take in order to control allergies affect the cancer prevention strategy? I guess this would be the subject of future studies.