Diagnoses of cancer among people aged 14 to 49 have risen by close to 80 percent since 1990, according to a large study published in the journal BMJ Oncology and reported by the Swedish science outlet Illustrerad Vetenskap. The publication spoke with Rosiered Brownson-Smith, a researcher in cancer and prevention at King's College London, about what may be driving the increase and what individuals can do about it.
Brownson-Smith told the outlet by email that the trend is troubling because a cancer diagnosis is traditionally associated with older age. She said growing numbers of people are being diagnosed during the years when they would expect to be at their healthiest.
Why it matters
The shift matters because it places a disease long tied to later life squarely in younger adulthood. According to Illustrerad Vetenskap, an expert group at the World Cancer Research Fund, which gathers and shares cancer research, has examined the rise in diagnoses in England, the Netherlands and the United States. Its figures show that the number of men under 50 with prostate cancer in England has nearly quadrupled, while other forms of cancer have doubled since 2001. Some cancer types have declined over the same period.
The expert group attributes the overall increase to three broad factors: changes in lifestyle, the surrounding environment, and a new approach to diagnosis. The researchers note that people have become more overweight, eat differently — including more processed food — and move less than they did a few decades ago. They also point to more sources of pollution in daily life, such as air pollution, chemicals and plastic. The group stresses that more people may also be diagnosed because knowledge about cancer is greater today.
Brownson-Smith, who is not part of the expert group, believes daily habits play a part. She told the outlet that one of the biggest challenges is that lifestyles have changed as a whole. In her view, many people choose the food that is easiest to prepare, which is often energy-dense and low in fibre, while new technology encourages long stretches of sedentary behaviour.
Bowel cancer and the years that count
Illustrerad Vetenskap reports that 1.9 million people develop bowel cancer each year. The cancer researcher Anne Tjønneland has spent years studying how to prevent the disease, and the outlet notes there is one particular food she would never serve to herself or her family. Over the past six years she has investigated how best to prevent colon and rectal cancer. The figures she cites show that people born in 1990 face four times the risk of developing bowel cancer before turning 50 compared with people born in 1960.
Brownson-Smith points out that the development of bowel cancer can take many years, which means childhood and adolescence may be important windows. She told the outlet that because the disease develops slowly, the teenage years in particular may matter for prevention.
She described her own approach as focusing on overall habits rather than fixating on individual ingredients or labelling foods as simply good or bad. According to Illustrerad Vetenskap, she aims for a varied diet with plenty of fibre-rich foods and tries to find time for exercise outside work.
The researcher also stressed that she and other cancer scientists do not yet know whether a single specific factor causes cancer. She said the field is in a race against time to understand the increase and to identify ways to prevent cancer before it develops.
What to watch
The expert group's assessment leaves the rise without a single explanation, and Brownson-Smith's advice rests on patterns rather than proven causes. Further research into early-life exposure and long-term diet will determine whether the upward trend can be slowed.
