Minimally processed, human-grade diet alters canine epigenetic ageing: Results from a pilot study

Diet plays a critical role in promoting wellness and longevity in both humans and canines. Epigenetic ageing clocks have emerged as accurate tools for assessing biological ageing and evaluating dietary and lifestyle interventions in humans and mice.

A dog-specific epigenetic ageing clock was developed and validated using buccal swab samples from domestic dogs aged 1.5 and 17 years. The clock exhibited a strong correlation with chronological age in both the training set (r = 0.99) and the validation set (r = 0.83). To investigate the impact of diet on epigenetic ageing, purebred pugs were assigned to either one group fed a minimally processed, human-grade food (MPHGF, n = 18 completed) or a processed, extruded dry kibble (EDK, n = 7 completed). Epigenetic age was assessed from buccal swabs collected at baseline and 6-month timepoints. Each dog served as its own control by calculating delta age (epigenetic age minus chronological age) over the study period.

Dogs fed with MPHGF diet exhibited a significant reduction in delta age, decreasing from 2.75 to 1.80 years over 6 months (p = 0.02), indicating a trend of slowed epigenetic ageing. In contrast, dogs fed with EDK diet exhibited no significant change in epigenetic ageing (p = 0.86). After sex-stratified analysis, females in the MPHGF group showed younger delta age at M6 than M0; however, not insignificant comparing to females in the EDK group.

This study demonstrates the potential for dietary interventions to influence epigenetic ageing in dogs and provides a practical, quantitative framework for investigating healthy ageing in companion animals.