There are promising animal studies showing that dietary restriction, including caloric restriction and intermittent fasting, may at least in some cases extend healthy lifespan and delay diseases aging for various species from yeast to mice to monkeys. The molecular mechanisms of these impacts involve the elimination or improved function of senescent cells, or damaged cells that have been marked by the body and prevented from dividing. Intermittent fasting may prime senescent cells for cellular recycling, which in the end can improve the function of aging tissues.
However, it is very difficult to study aging and senescence cell biomarkers in humans, especially because most people can’t or won’t participate in long-term intervention studies. Data from such studies in humans are rare, and the fields of caloric restriction and IF are no exception.
While IF can theoretically improve tissue function, particularly as it relates to metabolic function and circadian rhythms, more research is needed on the impacts of long-term fasting on healthspan and lifespan.