Researchers warn of an important new driver of cancer in under-50s - and it’s not smoking or poor diet

Key Points:

• A study by the Institute of Cancer Research and Imperial College London found 11 types of cancer, including thyroid, liver, colorectal, and breast cancers, are rising among 20 to 49-year-olds, with obesity identified as a significant contributing factor.
• While obesity is linked to most of the cancers increasing in younger adults, it does not fully explain the trend, and other factors such as ultra-processed foods, antibiotic use, and air pollution may also play roles, though evidence is inconclusive.
• The study revealed that traditional cancer risk factors like smoking, alcohol use, and poor diet have remained stable or declined, suggesting that the rise in obesity since 1995 is a key driver behind the increasing cancer rates in younger populations.
• Researchers emphasize the need for large-scale, long-term studies to uncover all biological and environmental causes of rising cancer rates in young adults, but stress that reducing obesity, particularly in children and young people, should be a public health priority.
• Cancer Research UK highlighted the complexity of the issue, noting that improved detection also contributes to higher diagnosis rates, and called for government action on smoking, junk food advertising, and access to healthy food to help prevent cancer.