Written on Tuesday, December 12, 2006 by Gemini
If you have four or more siblings then it’s better you get your brain scanned, for a new study has found that the number of your brothers or sisters, especially younger ones, can trigger your chances of developing a brain tumour.
The population-based study was conducted by a team of boffins led by Andrea Altieri with the German Cancer Research Centre in Heidelberg, Germany, who analysed 13,613 brain tumour cases in Sweden. The researchers found that people with four or more siblings were twice as likely to develop a brain tumour as people with no siblings. They also found that there was a two to fourfold increase in brain tumour rates among children younger than 15 who had three or more younger siblings compared to children of the same age who had no siblings.
The study did not find an association between the number of older siblings and brain tumours. Study author Andrea Altieri, said that the study suggested that infectious agents may be the reason behind the disease. “Since the size of a family and the number of younger siblings correlate with the incidence of brain tumours, this suggests infectious agents may be causing the disease,” Altieri said.
“The number of siblings a person has indicates they were exposed at an early age to infections, since children come in close contact with each other and thereby share exposures to many infectious agents,” Altieri added. The finding that brain tumour rates were higher among people with younger siblings, and not older siblings, also caused the researchers to suggest that infections or re-infections in late childhood may play an important role in causing the disease, while exposure to infections in infancy, birth to five months old, may be beneficial. The study is published in the December 12, 2006, issue of Neurology.