In general, it is observed that people who lead a fast and risky lifestyle often have accidents and die early. But in biology, animals that live fast tend to die earlier than animals with slow metabolisms.
However, in a particular species, the link between metabolism and lifespan is less clear.
Interventions, such as calorie restriction to prolong life, tend to have lower metabolic rates. Exercise does increase metabolism, but on average, it seems to make people live a little longer.
One problem with figuring out the effect of metabolism on longevity is that metabolism is often related to changes in body temperature. A low metabolic rate is often associated with a low body temperature.
So, when the calorie-restricted mice lived longer, it wasn’t clear if the extended lifespan was related to their low metabolism or lower body temperature.
In this study, the researchers used an unusual situation in which metabolic rate and body temperature move in opposite directions to determine which is more important.
When rats and hamsters are exposed to high temperatures, at their tropical peak, their metabolism decreases while their body temperature increases..
Professor John R. Speakman from SIAT, co-author of the study, said: “We found that exposure to these rodents shortens their lifespan. Lower metabolism is not extending their lifespan, but higher temperatures will shorten them.”
They used small fans to blow air over mice and hamsters exposed to high temperatures. This doesn’t affect their metabolism, but it does prevent them from having a high body temperature.
Based on these results, body temperature appears to be a much more important mediator of longevity than metabolic rate.
The researchers are now very excited about the finding, especially that using small fans to blow air over the animals reversed the effects of high ambient temperatures on lifespan by reducing heat. body temperature without altering the metabolic rate.
Source: Medindia
