Large analysis supports possible link between obesity and rare brain tumour

In collaboration with the Press Association

A very rare type of brain tumour may be slightly more common among people who are overweight or obese, according to a German analysis of existing research.

"This study adds to the evidence for a link in women and suggests for the first time that this may also affect men" - Sarah Williams, Cancer Research UK

The new analysis, published in the journal Neurology, supports previous evidence in women of a link between higher body mass index (BMI) and meningioma.

And the new findings suggest for the first time that being overweight may also affect men’s risk too. 

Sarah Williams, health information manager at Cancer Research UK, said this type of analysis was important for understanding what may cause rare cancers.

“Studies like this, which bring together previous research findings to help us build a clearer picture of the data, can be useful in rare cancers like meningioma where it’s hard to include large enough numbers of cases to get clear results,” she said.

“It’s too soon to be sure whether being overweight increases the risk of meningioma, but this study adds to the evidence for a link in women and suggests for the first time that this may also affect men,” she added.

Meningiomas develop in the layers of tissue that surround and protect the brain and spinal cord, known as meninges. Most are usually benign (non-cancerous), although some grow faster.

The University of Regensburg team analysed all available research on BMI, physical activity and two forms of brain tumour: meningioma and glioma. Twelve studies on BMI and six on physical activity were analysed, involving 2,982 meningioma cases and 3,057 glioma cases.

Compared to people with a normal weight, overweight people (BMI of 25 to 29.9) were 21 per cent more likely to develop a meningioma. Obese people (BMI of 30 or higher) appeared 54 per cent more likely to be diagnosed.

But given the rarity of these tumours, this increase in diagnoses would still only result in a small number of increased cases. The analysis also found no relationship between excess weight and glioma.

"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 study author Dr Gundula Behrens.

When the researchers looked at physical activity they found that meningioma appeared 27 per cent less likely to occur in patients who had the highest levels of physical activity, compared to those with the lowest levels.

Cancer Research UK’s Sarah Williams added that this result was ‘intriguing’, though while there are already known cancer-protective benefits of being active, more evidence is still needed to support these findings.

“Intriguingly, the research also hints that being more physically active might reduce meningioma risk, even after taking bodyweight into account,” she said.

“Keeping a healthy weight helps reduce the cancer risk. But we advise people to steer clear of fad diets and quick fixes – making small changes you can stick with in the long-term to eat more healthily and be more active will help you lose weight and keep it off for good.”