▎ WuXi AppTec content team editor
To live long, there's a secret that seems simple (whether you can do it or not is another matter). Just two words: eat less.
Without starvation and nutrition, calorie restriction can delay aging, prevent aging-related diseases, and prolong life. This strategy has been demonstrated at least in many animal experiments, from relatively simple nematodes and fruit flies to rats and primates that are closer to humans.
There was even a controlled study called "The Long-Term Effects of Reducing Energy Intake" (CALERIE) that recruited a group of human volunteers and found that strict adherence to a 14 percent reduction in calorie restriction diets helped reduce signs of aging in people.
Professor Joseph Takahashi, an academician of the National Academy of Sciences and National Medical College, led his research team to examine hundreds of mice over a four-year period.
Researchers raised hundreds of mice using automatic feeders, controlling the timing and amount of food each mouse ate throughout their lives, comparing the effects of different diet regimens on lifespan (Credit: Fernando Augusto/http://made-for.studio)
Their experiments showed that a 30 to 40 percent reduction in normal energy intake from a low-calorie diet was enough to extend the mice's lifespan by 10 percent.
Maybe a 10% extension isn't even much? On this basis, the research team slightly optimized the dieting protocol, also reducing caloric intake, feeding only during the period when the mice's metabolism was active, that is, letting the mice eat only at night - equivalent to humans only eating during the day.
After the low-calorie diet and the feeding time limit, the life of the mice was extended by 35%, which can be said to achieve the effect of doubling the results with half the effort!
As a control, some mice also maintained a low-calorie diet for a lifetime, but they ate casually or always ate during the day — the equivalent of humans eating supper every day. The results showed that they did not gain additional life-extending benefits.
▲ Mice with calorie restriction plus daytime fasting lived the longest (Image source: Reference[1])
The results of this experiment by Professor Takahashi's team have just been published in the journal Science.
In the research paper, the scientists further shed light on the reasons behind it, revealing at the cellular and genetic levels why such eating methods help slow aging.
The researchers note that as animals age, genes associated with inflammation tend to become more active, while genes that help regulate metabolism become less active. The study found that for mice that were diurnal and nocturnal, adhering to their circadian clocks and restricting calories at night helped counteract these genetic changes that occur with aging.
Notably, these mice did not become thinner despite eating less. The researchers found that whether they were limited to eating at night or during the day, although there was a huge difference in lifespan between several groups of mice, there was no difference in weight.
The results of this experiment are consistent with the results of recent clinical trials led by Chinese scholar Professor Zhang Huijie and published in the New England Journal of Medicine, an authoritative medical journal. The study showed that time-limited eating regimens did not further reduce weight or improve body fat or metabolic risk factors for obese patients on the basis of calorie restriction alone.
Therefore, combined with these new studies, the positive effect of limiting eating time on physical health is not in weight loss. Professor Takahashi has done a lot of outstanding work in the field of circadian clock research, and he believes that the effect of caloric restriction on factors related to the circadian clock can be further studied to find new ways to prolong human lifespan.
Although the current results are based only on mouse experiments, Professor Takahashi says he has gained some experience from them, limiting his eating time to 12 hours a day. "But if we can find a drug that works on the biological clock, we can test it in the lab to see if it can extend life." He said.
Resources:
[1] V. Acosta-Rodríguez et al., (2022) Circadian alignment of early onset caloric restriction promotes longevity in male C57BL/6j mice. Science Doi: Science 10.1126/science.abk0297
[2] Cutting calories and eating at the right time of day leads to longer life in mice. Retrieved May 5, 2022 from https://www.eurekalert.org/news-releases/951581
More recommendations
Click "Watching" and go again