TUESDAY, July 12 (HealthDay News) -- The immune systems of
people with contact allergies may be primed to protect against
certain types of cancer, including breast and brain cancers, new
research suggests.
Contact allergies occur due to direct contact with chemicals and
common metals such as nickel.
In the new study, researchers looked at almost 17,000 Danish
adults who were tested for contact allergies between 1984 and 2008.
About one-third (35 percent) tested positive for at least one
contact allergy. Women were more likely than men to have a contact
allergy -- 41 percent versus 26 percent.
When the study authors examined cancer cases among the
participants over the long term, they found that men and women with
contact allergies had significantly lower rates of breast and
non-melanoma skin cancer, and women with contact allergies also had
lower rates of brain cancer compared to those without contact
allergies.
But people with contact allergies had higher rates of bladder
cancer, which may be due to higher levels of chemical metabolites
accumulated in the blood, the researchers suggested.
The study, by Kaare Engkilde of the National Allergy Research
Centre at Copenhagen University, Gentoffe Hospital in Hellerup,
Denmark, and colleagues, is published in the July 12 online edition
of the journal
BMJ Open.
The findings did not allow the researchers to come to any
conclusions about cause and effect, and more study is needed, they
noted in a journal news release. "However, if these relations are
etiological, there are implications for understanding how contact
allergy can affect cancer development and vice versa," Engkilde's
team wrote in the report.
More information
The Asthma and Allergy Foundation of America has more about
allergies.