- The key to slowing aging process is to consume a diet low in calories
- A low-calorie diet prevents the effects of physiological aging
- Caloric restriction works effectively by rejuvenating the biological clock
Aging affects the biological clock's control of metabolism. The research team discovered that a low-calorie diet helps keep these energy processes humming and keep the body younger, reveals a new study.
The study was published in the journal Cell by Paolo Sassone-Corsi, director of the Center for Epigenetics & Metabolism at the University of California, Irvine, and colleagues.
The research team demonstrates as to how the body's biological clock or circadian rhythms change as a result of physiological aging. The clock-controlled circuit is directly connected to the process of aging and is based on energy metabolized within cells.
Energy metabolized within cells is under circadian controls.
In older mice, the 24-hour cycle in the circadian-controlled metabolic system remained the same. However, notable changes in the circadian mechanism were seen, which turns the genes on and off , and is based on the energy usage of the cells.
In simpler words, the processing of energy is inefficient in older cells.
Sassone-Corsi said that the mechanism works excellently in a young animal, but shuts off in an old mouse.
But in the second group, the older mice were fed 30 percent fewer calories for six months and it was found that energy processing within cells was not changed.
Caloric restriction works in a most powerful way by rejuvenating the biological clock, and in this circumstance, a good clock meant good aging, said Sassone-Corsi.
Prevent Aging With Low-Calorie Diet
A research team from the Barcelona Institute for Research in Biomedicine collaborated with the Sassone-Corsi team for a companion study detailed in Cell's current issue.
The skin of young and older mice were tested for body clock functioning in stem cells and was found that in the younger mice, most of the rhythmic functions were preserved due to a low-calorie diet.
"The low-calorie diet greatly contributes to preventing the effects of physiological aging," said Salvador Aznar Benitah, who co-led the Spanish study.
He also said: "Keeping the rhythm of stem cells 'young' is important because in the end these cells serve to renew and preserve very pronounced day-night cycles in tissue. Eating less appears to prevent tissue aging and, therefore, prevent stem cells from reprogramming their circadian activities."
These studies explain as to why a low-calorie diet slows down aging in mice and reveal that the implications for human aging could be wide ranging, according to the research teams from the UCI and Barcelona researcher teams.
The research team suggested that it is important to further study why metabolism has such a powerful effect on the stem cell aging process. By identifying the link that promotes or delays aging, further treatments could be developed that can regulate this link.
Previous fruit fly studies show that low-calorie diets can extend longevity. However, the research team of UCI and Barcelona is the first to demonstrate that restricting calories influence the body's circadian rhythms' involved with the aging process in the stem cells.
"These studies also present something like a molecular holy grail, revealing the cellular pathway through which aging is controlled," Sassone-Corsi said.
The findings of this research study provide a clear introduction on how to control these elements of aging from a pharmacological perspective.
The Circadian Connection
The circadian rhythm-metabolism link was first showed by Sassone-Corsi and his colleagues some 10 years ago. The research team identified the metabolic pathways through which a circadian enzyme protein (SIRT1) works.
The energy levels in the cells are sensed by the SIRT1 and its activity is modulated by how many nutrients a cell is consuming. SIRT1 helps cells resist oxidative stress and radiation-induced stress; and is also tied to the inflammatory response in diabetes and aging.
- Shogo Sato et al. Circadian Reprogramming in the Liver Identifies Metabolic Pathways of Aging. Cell (2017). Volume 170, Issue 4, P664-677.E11.