In a study conducted over four years by investigator Joseph Takahashi and colleagues from the Howard Hughes Medical Institute (HHMI), it was found that a reduced-calorie diet extended the lives of mice by 10%.
However, lifespan was extended by a significant 35% when mice were fed only at night-time – when they are most active. Could this research prove beneficial for humans?
In the study, hundreds of mice were housed with automated feeders to control when and how much they ate for its entire lifespan. Some of the mice could eat as much as they wanted, others had their calories restricted by 30-40%.
Those on calorie-restricted diets ate on different schedules: those that fed the low-calorie diet at night – either over a two-hour or a 12-hour period – lived the longest.
Interestingly, Takahashi noted his study found no differences in body weight among mice on different eating schedules, “however, we found profound differences in lifespan”.
An equivalent plan for people would mean limiting eating to daylight hours, when humans are most active.
According to Takahashi, the research could help better understand whether diets plans that advocate for eating only at certain times of day, work. While these plans may not speed weight loss in humans, they could potentially prompt health benefits that lead to a longer lifespan.
The lead researcher hopes that learning how calorie restriction impacts the body’s internal clocks as we age will help scientists find new ways to extend the healthy lifespan of humans – either through calorie-restricted diets or through drugs that mimic those diets’ effects.
“If we find a drug that can boost your clock, we can then test that in the laboratory and see if that extends lifespan,” said Takahashi.
‘Circadian alignment of early onset caloric restriction promotes longevity in male C57BL/6J mice’
Published online 5 May 2022
DOI: DOI: 10.1126/science.abk0297
Authors: Victoria Acosta-Rodriguez, Filipa Rijo-Ferreira, Mariko Izumo, Pin Xu, Mary Wight-Carter, Carla B. Green, and Joseph S. Takahashi.