Having a very old grandmother will have a greater impact on your lifespan than eating less calories, according to a US study at The Jackson Laboratory (JAX).
The scientists found genetically-encoded resilience was a critical factor in lifespan, and had a far greater impact than diet and even weight.
Karl Gunnar Johansson chair and professor at JAX Gary Churchill said the most robust participants kept their weight on, even in the face of stress and caloric restriction, and were the ones that lived the longest.
“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,” Professor Churchill said.
He said the study of 1,000 genetically diverse mice also suggested a more moderate level of calorie restriction might be the way to balance long-term health and lifespan.
The study also found that immune system health and traits related to red blood cells were more clearly connected to lifespan.
While traditional factors such as weight, body fat percentage, blood glucose levels and body temperature did not explain the link between cutting calories and living a longer life.
“While caloric restriction is generally good for lifespan, our data show that losing weight on caloric restriction is actually bad for lifespan,” Professor Churchill said.
Overall, mice on unrestricted diets lived for an average of 25 months, those on intermittent fasting diets lived for an average of 28 months, those eating 80 percent of baseline lived for an average of 30 months, and those eating 60 per cent of baseline lived for 34 months.
But within each group, the range of lifespans was wide; mice eating the fewest calories, for example, had lifespans ranging from a few months to four and a half years.
