Association between circadian clock gene expressions and meal timing in young and older adults

ABSTRACT

Ageing is associated with a decline in circadian clock systems, which correlates with the development of ageing-associated diseases. Chrononutrition is a field of chronobiology that examines the relationship between the timing of meal/nutrition and circadian clock systems. Although there is growing evidence regarding the role of chrononutrition in the prevention of lifestyle and ageing-related diseases, the optimal timing of meal intake to regulate the circadian clock in humans remains unknown. In this study, we investigated the relationship between clock gene expression and meal timing in young and older adults. In this cross-sectional study, we enrolled 51 healthy young men and 35 healthy older men (age, mean±standard deviation: 24 ± 4 and 70 ± 4 y, respectively). Under daily living conditions, beard follicle cells were collected at 4-h intervals over a 24-h period to evaluate clock gene expression. Participants were asked to record the timing of habitual sleep and wake-up, breakfast, lunch, and dinner. From these data, we calculated “From bedtime to breakfast time,” “From wake up to first meal time,” and “From dinner to bed time.” NR1D1 and PER3 expressions in older adults at 06:00 h were significantly higher than those in young adults (P = 0.001). There were significant differences in the peak time for NR1D2 (P = 0.003) and PER3 (P = 0.049) expression between young and older adults. “From bedtime to breakfast time” was significantly longer in older adults than in young adults. In contrast, “From dinner to bed time” was significantly shorter in older adults than in young adults. Moreover, higher rhythmicity of NR1D1 correlated with longer “From bedtime to breakfast time” (r =  −0.470, P = 0.002) and shorter “From wake up to first meal time” in young adults (r = 0.302, P = 0.032). Higher rhythmicity of PER3 correlated with longer “From bedtime to breakfast time” in older adults (r =  −0.342, P = 0.045). These results suggest that the peak time of clock gene expression in older adults may be phase-advanced compared to that in young adults. In addition, a longer fasting duration from bedtime to breakfast in both young and older adults and earlier intake of meals after waking up in young adults may correlate with robust clock gene expression rhythms.

KEYWORDS:

• Chrono-nutrition
• clock genes
• fasting duration
• sleep
• aging

Acknowledgments

The authors would like to express their gratitude to all the participants. We would also like to thank Editage for the English language editing of our manuscript.

Author contributions

MT, YT, MH, SS contributed to the processes of “Conceptualization,” “Formal analysis,” “Funding acquisition,” and “Investigation,” while MF, KH, KT, TI contributed to “Investigation,” “Formal analysis,” and “Roles/Writing” (original draft). “Supervision,” and “Writing” – review & editing. TN contributed to the processes of “Conceptualization,” “Investigation,” and “Writing” (reviewing and editing). All authors read and approved the final manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/07420528.2023.2256855.

Additional information

Funding

This work was supported by the Nakayama Foundation for Human Science (M.T.), SIP, ‘Technologies for creating next-generation agriculture, forestry, and fisheries’ (funding agency: Bio-oriented Technology Research Advancement Institution, NARO (S.S.)), and by the JST-FOREST Program (JPMJFR205G to S.S).