Body Mass Cancer
Could high BMI be responsible for nearly half a million cancer cases each year?
We know that obesity increases the risk of a range of diseases – but exactly what impact does high body mass index (BMI) have on cancer incidence? A research team led by Melina Arnold of the International Agency for Research on Cancer (IARC) attempted to answer that question with a global population-based study. The headline: 481,000 new cases (or 3.6 percent of cancer worldwide) in adults in 2012 could be attributed to high BMI. Perhaps more telling is the fact that a quarter of those obesity-related cancers could have been avoided had the mean BMI value from 1982 been maintained over the past 20 years... But we continue to get fatter.
The authors looked at the incidence of cancers associated with a high BMI (including rectal, colon and oesophageal cancer) in 12 geographical regions. Perhaps unsurprisingly, the incidence of obesity-related cancer was much higher in developed countries (see Figure 1), with around 64 percent occurring in North America and Europe. Notably, women are at higher risk than men, with endometrial and breast cancer accounting for a large portion of female cancer cases.
Figure 1. Proportion of all cancer cases attributable to high BMI by region. For further information, see reference 1.
But are all of these cases attributable to weight? The authors allowed a 10-year lag-time, linking BMI information from 2002 to cancer cases in adults over 30 in 2012. However, the effect of bodyweight on cancer risk is poorly understood, so the accuracy of the results given the chosen 10-year timeframe is uncertain – especially as a variety of cancers were included in the study. Geography (and hence ethnicity) was also not fully accounted for.
Despite any limitations of the study, it does seem very clear that large increases in BMI are affecting public health. “Our findings add support for a global effort to address the rising trends in obesity,” says Melina Arnold, “The global prevalence of obesity in adults has doubled since 1980. If this trend continues it will certainly boost the future burden of cancer, particularly in South America and North Africa, where the largest increases in the rate of obesity have been seen over the last 30 years.”
- M Arnold et al., “Global burden of cancer attributable to high body-mass index in 2012: a population-based study”, Lancet Oncol., 16, 36–46 (2015). PMID: 25467404
I have an extensive academic background in the life sciences, having studied forensic biology and human medical genetics in my time at Strathclyde and Glasgow Universities. My research, data presentation and bioinformatics skills plus my ‘wet lab’ experience have been a superb grounding for my role as an Associate Editor at Texere Publishing. The job allows me to utilize my hard-learned academic skills and experience in my current position within an exciting and contemporary publishing company.
