Skin epigenetic clocks tested against sun exposure and age
In an abstract, an exogenous skin clock was more strongly linked to sun-exposure measures than two endogenous clocks, while all clocks were tested against chronological age. This is an abstract only; the full text was not reviewed. [1]
Automatic summary · not editorially reviewed
The key findings
The source at a glance
- Study type / format
- Abstract of a clock-training and association study
- Population / context
- Skin samples used to train and test epigenetic clocks
- Summary based on
- Study abstract
- Original publication
- September 11, 2026
Exogenous versus endogenous skin ageing clocks
The source distinguishes endogenous skin ageing, influenced by factors inside the body such as blood nutrients and hormones, from exogenous skin ageing, caused by harmful factors penetrating the outer skin layer, the stratum corneum. Exogenous and endogenous skin clocks were trained in more than 400 skin samples. These two clocks and the Horvath 'Skin and Blood' epigenetic clock were then tested.
Supporting source [1]
Sun-exposure links stronger for exogenous clock
The clocks were tested for association with chronological age and, controlling for chronological age (age acceleration), with sun-exposure parameters and skin gene expression. Exogenous Skin clock ages were significantly associated with sun-exposure aspects, according to the abstract. The aim was to test whether an exogenous skin ageing clock is more strongly associated with sun-exposure aspects than two endogenous epigenetic clocks.
Supporting source [1]
Abstract-only scope and open questions
The abstract concludes that skin epigenetic clocks can differentiate exogenous from endogenous skin ageing, which could facilitate further study of the mechanisms behind these two phenomena. The abstract does not report sample details, effect sizes or the full results for the endogenous clocks and the Horvath clock. These are associations in skin samples, not evidence of causes or of effects on lifespan.
Supporting source [1]
How to interpret this
Abstract only; the full text was not reviewed. Sample details, effect sizes and full results for the endogenous and Horvath clocks are not reported here. Associations do not show causation.
Based on the study abstract; the full paper, tables and supplementary data were not reviewed.
Source & supporting passages
Shore CJ, Simons RB, Del Caño LR, Xiong Z, Pardo LM, Eecen CMW, Nijsten T, Small KS, Vidaki A, Kayser M, Bell JT, Shen YJ, Gunn DA. · europepmc.org · September 11, 2026