A new study has identified obesity as a major contributor to the rising incidence of cancer among younger adults in England. Researchers from the Institute of Cancer Research and Imperial College London analyzed data from 2001 to 2019 and found that 11 types of cancer, including bowel and ovarian cancer, are increasing in people aged 20 to 49.
Obesity as a Key Risk Factor
According to the study, obesity is the only known behavioral risk factor that has been on the rise among younger adults during this period. Other established risks such as smoking, alcohol consumption, red meat intake, and physical inactivity have either remained stable or declined in England. This led the researchers to conclude that the increase in obesity is a key driver behind the rising cancer rates.
Excess weight was associated with 10 of the 11 cancers identified, including thyroid, kidney, and pancreatic cancer. Oral cancer was the only exception. Maintaining a healthy weight could prevent about 20% of bowel cancers, 35% of endometrial cancers, and 27% of kidney cancers, the researchers noted.
Record High Cancer Diagnoses
The study comes amid recent figures showing that cancer diagnoses in the UK have reached a record high, with one person diagnosed every 80 seconds and more than 403,000 people diagnosed annually. Despite the clear link between obesity and cancer, the researchers caution that obesity alone does not fully explain the overall rise, suggesting that other unknown factors may also be at play.
Prof Montserrat García-Closas, co-director of the Cancer Epidemiology and Prevention Research Unit at the Institute of Cancer Research, emphasized the importance of addressing obesity. “Excess weight is an important contributor, although it cannot fully account for the scale of the rise in bowel and other cancers. This tells us that multiple factors – including early-life exposures – may be acting together,” she said. “Understanding these patterns is essential for identifying what is truly driving cancer risk in today’s generations. However, we cannot wait to act. Tackling obesity across all ages, particularly in children and young people, through stronger public health policies and wider access to effective interventions, could slow the rise in cancer and prevent many cancers – and must become a national priority.”
Trends Across Age Groups
The increase in cancer rates among younger adults mirrors trends seen in people over 50, with the exception of bowel and ovarian cancer. These two types were only observed to rise among younger people, with average annual increases of 3% and 0.7%, respectively.
Michelle Mitchell, chief executive of Cancer Research UK, commented on the findings: “Globally and in the UK, we’re seeing a small increase in cancer rates in adults under 50. The picture is complex and we need more research to understand what’s driving the trend, but this study helps to fill in some gaps. Overweight and obesity doesn’t explain the rise in full though. Improvements in detection are likely to also be playing a part, meaning that more people are being diagnosed at a younger age.”
Mitchell called for government action: “Preventing cancer cases must be a priority for the UK government. Measures to restrict the advertising and promotion of junk food, introducing mandatory reporting and targets on healthy food sales, and making nutritious food more accessible to everyone, would all help people keep a healthy weight.”
