Colon cancer is on the rise among young people – and research points to one major culprit | Devi Sridhar

If smoking was the cancer villain of the 20th century, eating ultra-processed food may be its 21st-century counterpart

• Prof Devi Sridhar is chair of global public health at the University of Edinburgh

Cancer used to be seen as part of ageing: something that mainly afflicted people over the age of 60 or 70. But although it is still true that the majority of new cancer diagnoses affect the over-70s, the pattern is changing in subtle ways. Some cancers are increasingly found in younger people.

Take colorectal (bowel) cancer: while rates have declined in those over 60, data shows a sharp increase in many developed countries among people under 50, in what's called early-onset disease.

Prof Devi Sridhar is chair of global public health at the University of Edinburgh