Alarming rise in colorectal cancer among those under 50 🩺

An unexpected phenomenon is worrying researchers: colorectal cancer, once rare before the age of 50, has seen a marked increase. This global trend raises questions about our lifestyles and their insidious effects.

Scientists from the American Cancer Society, led by Hyuna Sung, analyzed data from the World Health Organization. Between 1975 and 2017, colorectal cancer rates among 25-49-year-olds surged in 27 countries, including non-Western nations such as Japan and Turkey.


What stands out is that this increase cannot simply be attributed to improved screening. Most countries do not perform systematic tests before age 50, reinforcing the hypothesis of a more fundamental cause.

The connection to the Westernization of lifestyles is emerging as a common thread. Diets richer in meat and processed foods, combined with sedentary living, appear to be key factors. For example, in Japan, meat consumption has increased sevenfold since the 1960s.

However, the equation remains incomplete. Other elements may also contribute, such as pollution or unidentified genetic variations. Researchers stress that these factors still require in-depth investigation.

The affected geographical areas share a high human development index, based on life expectancy, education, and GDP. This supports the idea that economic development, often accompanied by cultural and dietary changes, could play a role.

Gaps persist in the data, notably for underrepresented regions such as Africa and parts of Asia. These limitations call for more comprehensive data collection to better understand disparities.

In response to these findings, initiatives are emerging to adapt prevention strategies. Informing young populations about symptoms like abdominal pain or rectal bleeding is becoming a priority.

The challenge remains immense: integrating prevention into healthcare systems often focused on older populations. The urgency of understanding the exact causes of this rise cannot be ignored.

What is colorectal cancer?

Colorectal cancer is a disease that affects the colon or the rectum, two parts of the large intestine. It develops from abnormal cells that form tumors, often on pre-existing polyps.

Symptoms include rectal bleeding, abdominal pain, or persistent changes in bowel habits, such as diarrhea or constipation. These signs can, however, go unnoticed or be mistaken for other benign disorders.

The main risk factors include a diet high in red meat and processed foods, a sedentary lifestyle, being overweight, and a family history of cancers or polyps.

Current prevention relies on regular screening from age 50 (or earlier for high-risk individuals), combined with a healthy lifestyle: a fiber-rich diet, physical activity, and limiting processed products.