We all want to live for as long as possible. Now new research offers some useful advice on what we could do with our diet to help give us the best chance.
It’s all to do with what some very clever people have found out about mice. A long-term reduction in calorie intake could be more beneficial for longevity than periodic fasting, academics say. It was based on a study with mice which suggested a “more moderate” approach to calorie restriction might be key for balancing longevity and overall health.
The study, published in Nature and conducted by American researchers, found an unexpected result: the longest-living mice were those that shed the least amount of weight despite their lower food consumption. These mice managed to maintain higher energy levels and more robust immune and reproductive systems, unlike their counterparts that lost more weight and tended to live shorter lives due to low energy and compromised biological systems.
Historically, laboratory evidence has shown that animals will live longer if they eat less food or eat less frequently. However, scientists have faced challenges in understanding why and how to best apply these restricted diets in humans.
In an effort to mimic human genetic variation, researchers at The Jackson Laboratory (JAX) in Bar Harbor, Maine monitored the health of over 900 genetically unique mice undergoing various diet regimes, shedding light on how such dietary practices might affect people differently, reports Surrey Live..
The study found that low-calorie diets extending the lives of mice regardless of their body fat or blood sugar levels. Professor Gary Churchill from JAX highlighted the findings, saying: “Our study really points to the importance of resilience. The most robust animals keep their weight on even in the face of stress and caloric restriction, and they are the ones that live the longest.”
He added: “It also suggests that a more moderate level of calorie restriction might be the way to balance long-term health and lifespan.” The research team, led by Professor Churchill, put female mice on one of five different eating plans.
These were an unrestricted diet, two calorie-restricted diets at 60% or 80% of their normal intake, and two intermittent fasting regimes where food was withheld for one or two days weekly but otherwise unrestricted. The mice were monitored until the end of their natural lives, undergoing regular health checks and blood tests.
Results showed that mice with no dietary restrictions lived an average of 25 months, those on intermittent fasting reached around 28 months, those consuming 80% of their usual diet lived up to 30 months, and those on the 60% calorie diet lived the longest, at 34 months.
A study has found that while diet can influence lifespan, genetics play a much more significant role. Mice on calorie-restricted diets had lifespans ranging from mere months to over four years.
The research team discovered that genetic factors were “far greater” in impacting lifespan than diet. This suggests that individual genetic traits, which are yet to be fully understood, are crucial in determining how diet affects a person’s health over time.
The researchers identified genetically-determined resilience as key to longevity. Mice that maintained their body weight, fat percentage, and immune health under stress or during food scarcity, and those that didn’t lose body fat later in life, lived the longest.
Prof Churchill remarked: “If you want to live a long time, there are things you can control within your lifetime such as diet, but really what you want is a very old grandmother.” The findings also question traditional beliefs about the benefits of certain diets.
They point out that factors like weight, body fat, blood sugar levels, and body temperature did not account for the relationship between reduced calorie intake and increased lifespan. The study discovered that rather than metabolism, it’s immune system health and traits concerning red blood cells that appear more directly linked to lifespan.
Researchers believe their findings indicate that human studies on longevity might be missing essential elements of ageing well by focusing primarily on metabolic markers. Prof Churchill noted: “While caloric restriction is generally good for lifespan, our data show that losing weight on caloric restriction is actually bad for lifespan. So when we look at human trials of longevity drugs and see that people are losing weight and have better metabolic profiles, it turns out that might not be a good marker of their future lifespan at all.”