For many years, cancer was seen mainly as a disease of older age. Most cancers become more common as people get older because cells slowly accumulate damage over time.
This damage can affect genes and normal cell functions, eventually leading to cancer. For this reason, many people expected cancer rates to continue being highest among older adults.
However, doctors around the world have noticed something worrying. More younger adults are being diagnosed with cancer. In some countries, rates of cancers such as colorectal cancer, lung cancer, and uterine cancer have been increasing in people under the age of 55.
This trend has puzzled scientists and raised an important question. Why are younger generations developing diseases that used to be seen mostly in older people?
A new study led by researchers at Washington University School of Medicine in St. Louis may provide part of the answer.
The research, published in the journal Nature Medicine, suggests that people born more recently may be aging faster at a biological level than people born decades ago. This faster biological aging may be increasing the risk of developing cancer at younger ages.
Scientists explain that there are two kinds of age. Chronological age is the number of years someone has lived. Biological age refers to how old a person’s body appears to be based on measurements of health and body function. Some people have bodies that appear younger than their actual age, while others have bodies that seem older than expected.
The researchers studied information from more than 154,000 people in the United Kingdom and more than 10,000 people in the United States. These participants came from two large health projects that collect information about people’s health, biology, and lifestyles.
To estimate biological age, the scientists looked at many markers in the blood. These included substances linked to liver function, kidney health, metabolism, and other body systems. They also measured proteins that could reveal how well different organs and tissues were aging.
The results showed that younger generations had older biological profiles than previous generations at the same age. For example, people in the United Kingdom born between 1965 and 1974 appeared biologically older than those born between 1950 and 1954.
The pattern was even more striking in the United States, where people born during the 1990s appeared biologically older than those born in the late 1960s.
This faster biological aging was linked to cancer risk. The researchers found that people with greater biological aging had an 8% higher risk of developing early-onset solid cancers. Those with the highest levels of biological aging had a 15% higher risk compared with those who showed the least aging.
The researchers also discovered that aging in certain body systems may influence specific cancers. People whose immune systems appeared older than expected had a greater risk of early-onset lung cancer. People whose fat tissue seemed biologically older had a greater risk of developing early-onset colorectal cancer.
The reasons behind accelerated biological aging are still not fully understood. Scientists suspect that many factors may work together. Obesity, poor diet, physical inactivity, alcohol use, metabolic problems, stress, and environmental exposures may all contribute.
Modern lifestyles are very different from those of previous generations. Many people spend long hours sitting, eat more processed foods, sleep poorly, and experience high levels of stress. These changes may gradually leave biological marks on the body.
The researchers believe that measuring biological age could eventually become an important tool in medicine. If doctors can identify people who are aging faster while they are still healthy, it may become possible to offer prevention strategies much earlier.
These strategies could include lifestyle changes, more frequent screening tests, or personalized monitoring programs.
The findings also remind us that health is influenced by the body as a whole. Cancer may not simply result from damage in individual cells. It may also reflect broader changes occurring across many organs and systems over many years.
The study cannot prove that faster biological aging directly causes cancer, and more research is needed to understand exactly why younger generations appear to be aging more rapidly.
Still, the findings provide an important clue in one of today’s biggest medical mysteries. Understanding why more young adults are developing cancer could eventually help doctors prevent disease before it starts and create more personalized ways to protect health.
If you care about cancer, please read studies that artificial sweeteners are linked to higher cancer risk, and how drinking milk affects risks of heart disease and cancer.
For more health information, please see recent studies about the best time to take vitamins to prevent heart disease, and results showing vitamin D supplements strongly reduces cancer death.
Source: Washington University School of Medicine in St. Louis.
