Brain tumors or meningiomas occur at a rate of five to eight cases per 100,000 people and the five year survival rate is 63%. Obesity was defined as a BMI index of 30 or higher and obesity was defined as having a BMI of 25 to 25.9.
A new study, published in the online issue of Neurology, has determined that obesity is linked to a twenty-one percent increased risk in brain tumors. The researchers analyzed all of the available research on body mass index, physical activity, and the brain tumors meningioma and glioma, the most common primary brain tumors in adults. A total of 12 studies on body mass index and six on physical activity were analyzed, involving 2,982 meningioma cases and 3,057 glioma cases.
“This is an important finding since there are few known risk factors for meningioma and the ones we do know about are not things a person can change,” said meta-analysis author Gundula Behrens, PhD, of the University of Regensburg in Regensburg, Germany. “Given the high prevalence of obesity and the unfavorable prognosis for this type of tumor, these findings may be relevant for strategies aimed at reducing the risk of meningioma.”
An association was determined between several biological processes, excess weight and increased risk of meningioma. Excess weight is associated with excess production of estrogen, and estrogens promote the development of meningioma. Excess weight is linked to high levels of insulin, which could promote meningioma growth. Behrens noted that the analysis does not prove that excess weight and lack of physical activity causes the brain tumors; it shows the association. “With physical activity, it’s possible that meningiomas that had not been diagnosed yet caused people to reduce their physical activity at the time it was measured,” she said. “As a reminder, while there was an association in the study between weight and this type of tumor, it should be noted that tumors are rare.”