7/31/2026
Yesterday I was rather disturbed when I read some new medical research about biological aging and early-onset cancer. I especially wanted to share the findings with the younger generation.
A study published last month in Nature Medicine, titled "Biological aging and generational shifts in early-onset cancer risk," analyzed 154,169 participants from the UK Biobank, with partial validation in more than 10,000 participants in the U.S.
The researchers compared people from different birth cohorts using several measures of biological aging, including PhenoAge, the Klemera-Doubal method, and metabolomic measures.
The results:
In the UK data, people born between 1965 and 1974 had a 23% higher standardized PhenoAge age gap than those born between 1950 and 1954. In other words, at the same chronological age, people in the more recent birth cohorts appeared to have more advanced biological aging. The pattern was also seen in the U.S. data: people born between 1990 and 1999 had a substantially higher PhenoAge age gap than those born between 1965 and 1969.
More importantly, greater biological aging was associated with a higher risk of early-onset solid cancers. Each standard-deviation increase in the PhenoAge age gap was associated with an 8% higher risk of early-onset solid cancer in the UK cohort. The researchers also found associations between immune-tissue aging and early-onset lung cancer, and between adipose-tissue aging and early-onset colorectal cancer.
Another recent review, "Early-onset colorectal cancer as an emerging disease of metabolic dysregulation," points to a related concern: early-onset colorectal cancer has been increasing, particularly in high-income countries, at the same time that obesity and metabolic disorders have become more common among younger people.
Researchers are investigating whether obesity, insulin resistance, chronic inflammation, altered gut microbiota, sedentary lifestyles and poor diet may contribute to an environment that makes colorectal cancer more likely.
We should be careful, however. These studies do not prove that overeating or obesity directly causes the generational increase in biological aging or early-onset cancer. Cancer has many causes, and the researchers emphasize that the full explanation remains unknown. Other possible contributors include alcohol, sleep disruption, environmental exposures, socioeconomic conditions and factors that scientists have not yet identified.
Still, there is an important lesson here.
I think about what my 95-year-old mother has told me about her childhood, youth and most of her adult years. Her generation experienced famine and malnutrition. Today's younger generation lives in almost the opposite environment: food is abundant, inexpensive and available all the time. Nutrition is way too much.
That transformation is one of humanity's great achievements. But abundance brings its own challenge. Together with it is new food processing technologies making it harder to resist over eating.
For greater part of human history, the problem was food shortages. Today, we live in an age of abundant food, but our bodies have not evolved quickly enough to adapt to this abundance.
Perhaps we need to learn a new kind of discipline: just because we have more does not mean we should eat more.
We cannot control every environmental factor that may influence biological aging or cancer. But we can control some of the basics: how much we eat, what we eat, how active we are, how much we sleep, and whether we allow excess weight and metabolic problems to develop.
My hope is that the younger generation can enjoy the abundance without becoming victims of that abundance.
