A new study published in Nature Communications reports that stronger adherence to healthy diet quality scores was associated with slower epigenetic ageing and distinct DNA methylation patterns in two population-based cohorts.
Researchers analysed data from the Rhineland Study in Germany and validated their findings in the EPIC-Potsdam cohort, examining 10 commonly used diet quality scores across the adult lifespan. The work assessed second- and third-generation epigenetic indicators of biological age, including GrimAge, PhenoAge and DunedinPACE, alongside epigenome-wide DNA methylation profiles.
Different healthy diets appeared to converge on similar biological pathways
The study found minimal overlap in the specific CpGs or genes associated with different diet quality scores, but a substantial overlap in the biological pathways they influenced. These shared pathways included cell signaling, metabolism and neurogenesis, suggesting that different healthy dietary patterns may act through similar underlying mechanisms even when their nutritional composition varies.
The authors also reported that adherence to a healthy dietary pattern was associated with reduced epigenetic ageing, although the strength of the association differed across diet quality scores. The findings were replicated in the EPIC-Potsdam cohort, which supported the overall pattern observed in the discovery analysis.
Signals were strongest in current smokers
One notable result was a stronger association between diet quality scores and epigenetic ageing acceleration in current smokers. The researchers said this pattern was also replicated in the validation cohort, and they did not find evidence that it was simply explained by smokers having generally better diets.
The study also suggested that cardiometabolic factors may lie on the causal pathway between diet quality and epigenetic ageing, as some associations were partially attenuated after adjustment for BMI and after excluding participants with prevalent hypertension or diabetes.
What the findings mean for nutrition research
The authors said the results support the idea that broadly healthy eating patterns may benefit ageing at the population level, while also hinting at diet-specific pathways that could eventually inform personalised advice. They noted that the EAT-Lancet diet showed little to no association with some accumulated-age markers, but was linked to DunedinPACE, which captures the current pace of ageing.
Although the study was observational and based largely on participants of European ancestry, the consistent findings across cohorts add to growing evidence that diet quality may influence biological ageing through measurable epigenetic changes. The researchers said further work is needed to understand how different dietary patterns interact with ageing processes over time.
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