Molecular Aging Is Unique to Each Person, New Study Finds

Molecular Aging Varies Widely Across Individuals, Study Reveals

Unlike prior studies that rely on single-timepoint snapshots, this research analyzed repeated blood samples from 335 women in the TwinsUK cohort, a database of over 15,000 twins. Over eight years, 5,061 genes and 181 metabolites showed significant changes, with most following consistent trends but some genes and metabolites exhibiting divergent patterns. “Even when most people’s genes or metabolites moved in one direction, we still found groups moving the opposite way,” said study co-author Kerrin Small, a professor of genomics at King’s College London.

The findings highlight the limitations of existing “biological age” scores, which estimate cellular health relative to chronological age. Raghav Sehgal, an associate research scientist at the Yale School of Medicine, noted that “no single number can fully capture the many systems that age at different rates.” The study also identified seasonal and circadian influences on molecular markers, with about a quarter of genes and 40% of metabolites fluctuating based on time of day and season.

The study tracked changes in more than 16,000 genes and 915 metabolites, identifying over 100,000 gene-metabolite associations. These links reveal how interconnected biological systems are, with immune function, metabolism, and age-related conditions like heart disease and neurodegenerative disorders showing significant molecular shifts. However, the research’s focus on women and use of blood samples means larger and more diverse studies are still needed.

One unexpected finding was the decline in blood levels of per- and polyfluoroalkyl substances (PFAS), including PFOA and PFOS. Researchers suspect this trend reflects U.S. or UK restrictions on their use in the U.K., though the study could not show that the chemicals themselves caused those changes.

The study’s longitudinal design allows for insights into how aging unfolds over time. For instance, each woman’s overall metabolite profile also became less similar to her earlier profile. This aligns with Sehgal’s assertion that “I would not call aging unpredictable, but it is certainly more individualized and context-dependent.”

Despite its contributions, the study has limitations. It was observational, included only women and relied solely on blood samples, necessitating larger and more diverse studies. The research team now plans to track molecular changes over about 15 years, up from eight in the current study. “Understanding these individual trajectories could one day help researchers distinguish healthy aging from molecular changes linked to disease, but that application is still a long way off,” said study co-author Julia El-Sayed Moustafa, a computational genomics researcher at King’s College London.

As research continues to unravel the molecular underpinnings of aging, the emphasis on individualized care grows more critical.

Disclaimer: The information provided in this article is for educational and scientific communication purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider regarding any medical condition, diagnosis, or treatment plan.