In a new commentary published in the International Journal of Epidemiology, the results of analyses conducted by researchers from the International Agency for Research on Cancer (IARC) indicate that the effect of overweight and obesity on risk of cancer is at least twice as large as previously thought.
The team conducted genetic analyses on eight common obesity-related cancer types. They compared the genetic Mendelian randomization estimates of the association between body mass index (BMI) and cancer risk with the estimates from classical cohort studies.
Excess body fatness is already recognized as an important cause of cancer and has been estimated to account for 6% of all cancers in high-income countries. According to the results of this new analysis, the proportion of cancers attributable to overweight and obesity is, in fact, substantially higher.
Mariosa D, Carreras-Torres R, Martin RM, Johansson M, Brennan P
What can Mendelian randomization tell us about causes of cancer?
Int J Epidemiol, 48(3):816–21. Published 25 July 2019;