One of the stories frequently heard in the news in the U.S. these days is that "cancer is rapidly increasing among the younger generation."

In the past, cancer was primarily considered a disease of the elderly, but in recent years, it has been reported that cancer is increasing at an astonishing rate among adults under 50, not only in the U.S. but globally. Both doctors and scientists are focusing on analyzing the causes, reporting that this is not just a coincidence but a fundamental change in modern lifestyles and environments.

According to data released by the American Cancer Society in 2025, the incidence rate among young women has notably increased. The cancer incidence rate for women under 50 is a staggering 82% higher than that of men, up from 51% in 2002, which is nearly a 30 percentage point increase.

Particularly, cancers of the digestive system, such as colorectal cancer, rectal cancer, pancreatic cancer, stomach cancer, uterine cancer, and kidney cancer, are showing significant increases.

Reports indicate that early-onset colorectal cancer has increased by 79% worldwide between 1990 and 2019. In fact, major hospitals in the U.S. have lowered the recommended age for colorectal cancer screenings from 50 to 45 for this reason. Researchers agree that it is difficult to explain this solely by genetic factors.

Scientists are paying attention to environmental factors experienced by generations born after the 1950s, such as exposure to pollutants, the spread of processed foods, and sedentary lifestyles. The main causes identified are obesity, lack of exercise, and excessive consumption of ultra-processed foods.

Obesity causes inflammation in the body and disrupts hormonal balance, increasing cancer risk, and studies have confirmed that processed foods high in sugar or fat raise the risk of colorectal and pancreatic cancers. When combined with factors like poor sleep habits, alcohol consumption, and smoking, the risk increases significantly.

For women, delaying childbirth and having fewer children are also reported to contribute to the increased incidence of some cancers. Another interesting aspect is the change in gut microbiota. Modern dietary habits and increased antibiotic use have altered the gut environment, which may indirectly or directly affect digestive system cancers.

Researchers at Memorial Sloan Kettering Cancer Center in New York pointed out that "the simultaneous increase of various cancers among young women is a problem beyond simple genetic mutations." In other words, it is not our bodies that have changed, but the 'environment' we live in.

These days, many people on the internet are asking, "Is the COVID vaccine related to the increase in cancer?" However, all scientific data so far shows no causal relationship between the COVID vaccine and cancer occurrence. Major institutions like the National Cancer Institute and Mayo Clinic have clearly stated that there is no evidence that vaccines cause or worsen cancer.

In other words, the cause of the increase in cancer among young people is more closely related to changes in the living environment rather than the vaccine. Observing the rapid increase in colorectal cancer patients in their 30s and 40s raises the question, "Why at this age?" In reality, many people overlook symptoms like constipation, blood in stool, and abdominal pain.

Therefore, it is recommended to get tested immediately if symptoms occur, regardless of age, and especially if there is a family history, to undergo early screening even before the age of 40. First, do not delay screenings and set a schedule appropriate for your age, and gradually change your lifestyle. About 150 minutes of exercise per week, reducing ultra-processed foods, a diet focused on vegetables and whole grains, sufficient sleep, stress management, and avoiding smoking and excessive drinking are essential.

Antibiotics should only be taken when absolutely necessary, and it is also important to develop a habit of being sensitive to the body's signals. In fact, these changes may seem trivial at first, but researchers say that such lifestyle improvements could prevent about 40% of all cancers.

While it is concerning that stories of young people getting cancer are increasingly appearing in the news, starting from this moment, if we gradually change our diet, sleep, and activity levels, the statistics could be different in ten years.