Researchers from the International Agency for Research on Cancer did a population study in which they looked at BMI index and cancer incidence in adults aged 20 or older.
They assumed a 10-year lag period between high BMI and the occurrence of cancer and tested the effect of various model assumptions. BMI index is used to measure body fat and is based on one’s weight and height.
The study, published in the Lancet's Oncology medical journal, revealed that in 2012 excess body weight was the reason behind 481,000 new cases of cancer, mostly in North America and Europe. This represented 3.6% of all new cancers in 2012.
Its results also suggested that women face a bigger risk than men, as 5.4% of obesity-related new cancers affected women in 2012, compared to 1.9% affecting men. They also showed the risk was geography-related.
“The burden of attributable cases was higher in countries with very high and high human development indices. Corpus uteri, postmenopausal breast, and colon cancers accounted for 63·6% of cancers attributable to high BMI. A quarter (about 118 000) of the cancer cases related to high BMI in 2012 could be attributed to the increase in BMI since 1982,” said the researchers.
“These findings emphasise the need for a global effort to abate the increasing numbers of people with high BMI. Assuming that the association between high BMI and cancer is causal, the continuation of current patterns of population weight gain will lead to continuing increases in the future burden of cancer,” they added.
About 35% of the adult population globally is classified as overweight (BMI ≥25 kg/m2), including 12% of people who are classified as obese (BMI ≥30 kg/m2), according to UN research.
Source: Lancet Oncology
Published online ahead of print doi:10.1016/S1470-2045(14)71123-4
Global burden of cancer attributable to high body-mass index in 2012: a population-based study
Authors: M. Arnold, N. Pandeya, G. Byrnes et al.