Rising dietary risk-attributable mortality from colon and rectum cancer among adults aged 60+ years in Japan: a nationwide study

Colon and rectal cancer (CRC) remains a major cause of cancer mortality in older adults, and dietary factors are important, potentially preventable contributors. Here, we assessed nationwide trends in CRC mortality and dietary risk-attributable burden among Japanese adults aged ≥60 years from 2010 to 2023. CRC deaths rose from 48,208 in 2010 to 70,327 in 2023, and the death rate increased from 121.9 to 159.4 per 100,000 population (EAPC 1.75). Mortality increased in both sexes, remained consistently higher in males, and showed the largest growth in the oldest age groups, especially those aged ≥85 years. Roughly two-fifths of CRC deaths over the study period were attributable to dietary risks; the attributable proportion increased from 39.75% to 40.66%, and dietary-attributable deaths rose from 19,156 to 28,582. Diets low in whole grains and milk were the leading contributors across sexes, age groups, and prefectures, followed by diets high in red meat, while contributions from processed meat consumption and low fiber intake increased over time. CRC mortality and dietary-attributable burden varied markedly across prefectures, although attributable proportions were relatively stable. These findings highlight a growing CRC burden in Japan’s aging population and support age- and region-tailored dietary prevention strategies.