How coffee is prepared may matter as much as how much people drink, with filtered and instant coffee showing sharply different associations with biological ageing markers, according to a study published in npj Science of Food.
Researchers analysed data from 49,414 UK Biobank participants with an average age of 56.4 years. They assessed three measures of biological ageing: relative leukocyte telomere length (rLTL), a biomarker of cellular ageing, and two composite measures (PhenoAge Acceleration and KDM-BA Acceleration) that quantify biological age based on biochemical and clinical parameters.
Compared with non-consumers, filtered coffee intake showed significant overall trends toward lower biological age acceleration scores and longer telomere length, consistent with slower ageing. By contrast, instant coffee consumption showed significant overall trends toward higher age acceleration scores and shorter telomere length, consistent with accelerated ageing. No significant associations were observed for other coffee types.
The researchers noted that most instant coffee effect estimates corresponded to approximately 0.1 to 0.2 years of age acceleration, which they described as marginally clinically significant at the individual level.
Mediation analysis identified glycoprotein acetylation, basal metabolic rate, and cystatin C as potential statistical mediators of some associations. Subgroup analyses suggested the associations were more pronounced in certain groups, including males, people aged 60 years and older, and current smokers.
The authors acknowledged important limitations, including the cross-sectional design, which cannot establish causation. Self-reported coffee intake, possible residual confounding, and the predominantly White study population also limit interpretation. Prospective and intervention studies are needed before the results can inform dietary guidelines.
Source: News Medical / npj Science of Food (2026)
