A new study published in Nature Medicine suggests that millennials and Gen Z are biologically older than people of the same chronological age were decades ago, a shift researchers say may help explain rising cancer rates among young adults worldwide. The article is based on an interview by Iris Koll with Prof. Ido Wolf of Ichilov, and cites concerns about increasing cases of colon, uterine and lung cancers in younger people.
Researchers analyzed data from more than 164,000 participants in two large medical databases in Britain and the United States. They used PhenoAge, a measure of biological age built from chronological age and nine blood markers, including inflammation, blood sugar, kidney function, albumin and white blood cell counts, to calculate the gap between actual age and biological age.
The findings were striking. In Britain, people born between 1965 and 1974 had a biological age 23% higher than peers born in the early 1950s. In the United States, the gap was even larger, with those born in the 1990s showing a biological age 92% higher than people born in the 1960s at the same age. The researchers also found that each one standard deviation increase in biological aging was linked to an 8% higher risk of cancer before age 55.
The strongest associations were seen for lung cancer, with a 57% higher risk, as well as digestive system cancers and uterine cancer. The link remained significant after accounting for known risk factors such as smoking, obesity, telomere length and genetic predisposition.
The researchers said they do not yet know the exact cause, but suspect a combination of processed food, inactivity, obesity, chronic stress, sleep disruption and environmental pollution. Prof. Yain Cao said the goal is to identify young people at high cancer risk while still healthy, so prevention and early detection can be tailored to them. Dr. David Scott said there is no single explanation for the rise in early-onset cancer, but studies like this show it is tied to changes across the whole body, not only in individual cells.
