Can eating less help prolong lifespan?

According to Medical News Today, researchers have recently discovered through a mouse model that consuming fewer calories may help extend lifespan.

However, the longest-lived mice lost the least weight while following a calorie-restricted diet.

This longevity research comes from scientists at the Jackson Laboratory in Bar Harbor, Maine, and Calico Life Sciences in South San Francisco, California.

The Link Between Longevity and Diet

Researchers have found through a mouse model that eating fewer calories may help extend lifespan – (Photo: Cathe Friedrich)

Previous studies have shown that what we eat can influence the aging process and lifespan. Different diets such as the Mediterranean diet, intermittent fasting, and calorie restriction have been proven to help increase longevity.

In the new study published in the journal Nature, scientists report that certain genetic factors, such as genetic resilience, may play a larger role in extending lifespan than diet alone.

The researchers used 960 genetically diverse female mice, divided into five different diet groups, including a calorie limit of 60% or 80% of daily caloric intake; fasting for one or two consecutive days each week without caloric restriction; and ad libitum feeding, allowing the mice to eat whatever and whenever they wanted.

“Due to the difficulty of applying this to humans, we turned to a genetically diverse mouse model,” explained Dr. Gary Churchill, a professor at the Jackson Laboratory and the lead author of the study.

“Recent studies have suggested that in mice, some individuals (genotypes) may have shorter lifespans when calorie-restricted. We were interested in determining whether lifespan extension through calorie restriction is universal and whether the benefits depend on the level of calorie restriction (20% versus 40%).” Dr. Andrea Di Francesco, a senior scientist at Calico Life Sciences and also an author of the study, stated.

Longer Lifespan with Calorie Restriction

At the conclusion of the study, scientists found that while mice allowed to eat anything at any time lived an average of 25 months, those on an intermittent fasting regimen had an average lifespan of 28 months.

Mice subjected to calorie restriction achieved the longest lifespans – those eating 80% of their baseline caloric intake lived an average of 30 months, while those eating 60% lived an average of 34 months.

“We were surprised that extreme calorie restriction (40%) extended lifespan to such a significant extent, with no sign of shortened lifespan in any of the mice.

We believe that in a genetically diverse population—a unique feature of this study—some animals may experience reduced lifespan when subjected to 40% calorie restriction or a two-day intermittent fasting regimen,” Churchill remarked.

The researchers also discovered that genetic factors, such as genetic resilience, play a more significant role in extending lifespan than diet in the mouse model.

“Diet is not a magic solution – it can increase average lifespan but does not guarantee long-term longevity for an individual. There are other factors that contribute to longevity that are at least equally important,” Di Francesco explained.

“Weight loss is ‘good’ from a human perspective, but weight loss does not cause an extension of lifespan – they are separate outcomes of calorie restriction,” Churchill noted.

Need for Human Translation of Research

After reviewing the study, Dr. Mir Ali, a bariatric surgeon and the medical director of the MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, California, stated that what is interesting about the research is that it shows reducing calorie intake or eating less increases lifespan, but does not necessarily require weight loss, which he considers counterintuitive.

“Animal studies are a good starting point, but clearly, animals are very different from humans. We need to see whether research conducted on animals applies to humans,” Ali said.

According to Richard, “the body is always in a state of self-regulation, constantly trying to find balance to achieve a state of ‘just enough’ – operating smoothly across all aspects.”