According to a study of more than 400,000 adults in the UK , presented at the European Obesity Congress (ECO) held online this year, obesity increases the risk of developing 10 of the most common cancers .
The data are similar regardless of how obesity is measured, such as central fat (larger waist and hips) or general obesity (body mass index (BMI) and body fat percentage).
The ten cancers
Using data from the UK Biobank prospective cohort study, researchers at the University of Glasgow identified 437,393 adults (54% female; mean age 56 years) who did not have cancer, to investigate the risk of developing and dying from 24 cancers according to six obesity markers: BMI, body fat percentage, waist-to-hip ratio, waist-to-height ratio, and waist and hip circumferences.
Results were adjusted for age, sex, ethnicity, education, smoking, alcohol consumption, fruit and vegetable intake, red and processed meats, blue fish, physical activity, and sedentary behaviors. After an average follow-up of 9 years, there were 47,882 cancer cases and 11,265 cancer deaths .
The researchers found that all six obesity measures were positively and similarly associated with an increased risk of 10 cancers . For example, each 4.2 kg (men) and 5.1 kg (women) increase in BMI above 25 kg (defined as being overweight) was associated with an increased risk of stomach cancer (35% increase) , gallbladder (33%), liver (27%), kidney (26%), pancreas (12%), bladder (9%), colorectal (10%), endometrial (73%), uterine (68%), postmenopausal breast cancer (8%) and general cancer (3%).
Researchers estimate that whether these associations were causal or non-correlational, being overweight or obese could be responsible for about 40% of uterine and endometrial cancers and 29% of gallbladder cancers; and it could represent 64%, 46% and 40% of deaths from these cancers, respectively.
The results suggest that BMI is an appropriate measure of cancer risk from being overweight, and there is no advantage to using more complicated or expensive measures such as waist circumference or body fat percentage.