Some studies have found that species with fast growth and metabolism usually also have shorter lifespans.
In other species, however, the link between metabolic rate and lifespan is not obvious, for example, restricting calorie intake and exercise can reduce and increase metabolic rate, respectively, but both can extend lifespan.
In addition, restricting calorie intake usually leads to lower body temperature, so it is difficult to say which of these two factors extends lifespan.
In a recent study published in Nature Metabolism, researchers from the Shenzhen Institute of Advanced Technology of the Chinese Academy of Sciences, Wenzhou University and the University of Aberdeen found that lower body temperature is a key factor in increased lifespan.
When they placed mice and hamsters in a warmer environment (32.5°C), the body temperature of these animals increased, the metabolic rate of the body decreased and the life span was shortened.
When the researchers cooled these animals with a small fan, their metabolic rate was not affected, but their body temperature was reduced, which in turn prevented these animals from dying prematurely due to high body temperature.
Based on this experiment, the researchers believe that body temperature may have a greater effect on lifespan relative to metabolic rate.