People who are overweight or obese are at greater risk of developing cancer, according to the largest study of its kind.
Researchers from the London School of Hygiene and Tropical Medicine gathered data on 5.2 million people in the UK, of which nearly 170,000 developed cancer, and found that a person’s Body Mass Index, a measure of body fat, was linked to 17 out of 22 cancers.
The findings, published in The Lancet medical journal, suggest BMI was “positively associated” with 10 most common cancers, including uterus, cervix, thyroid, kidney, liver and colon. Post-menopausal breast cancer and leukaemia were also a heightened risk, the scientists said.
Each 5 kg/m² increase in BMI linked to higher risk of 10 cancers:
- Uterus (62% increase)
- Gallbladder (31%)
- Kidney (25%)
- Cervix (10%)
- Thyroid (9%)
- Leukaemia (9%).
- Liver (19% increase)
- Colon (10%)
- Ovarian (9%)
- Breast cancers (5%)
Based on the results, the researchers estimate that excess weight could account for 41% of uterine and 10% or more of gallbladder, kidney, liver, and colon cancers in the UK.
A person is deemed to be overweight if they have a BMI score, calculated using their weight and height, of 25 to 30 and are obese if it is above 30.
The study, funded by the National Institute for Health Research, Wellcome Trust and Medical Research Council, also suggested if waistlines continued to grow then there could be 3,790 more cancer sufferers per year.
The study authors said they estimated that a 1 kg/m2 population-wide increase in BMI would result in 3,790 additional annual UK patients developing one of the 10 cancers positively associated with BMI.
Dr Krishnan Bhaskaran, who led the study, told the Daily Mail more than 12,000 cases of the 10 most common cancers could be attributed to obesity.
“The number of people who are overweight or obese is rapidly increasing both in the UK and worldwide,” he said.
“It is well recognised that this is likely to cause more diabetes and cardiovascular disease. Our results show that if these trends continue, we can also expect to see substantially more cancers as a result,” he said. “The higher the BMI, the higher the risk.”
It comes after a report by Nuffield Health in April revealed many people were unaware they were overweight or of the health risks it could lead to.
Research conducted by the charity found that two-fifths of obese people had no concerns about serious illness due to their weight.
Speaking at the time, Dr Davina Deniszczyc, medical director for well-being at Nuffield Health, said: “We are seeing a vast number of people unwittingly straying into dangerous medical territory and perhaps not realising that the obesity awareness campaigns are directed at them.”