14 DAY TRIAL // People with higher-than-normal energy levels could be prone to early natural mortality, the conclusions of a new study indicate. The work reveals that those with high metabolic rates may in fact be aging quicker than those with slower metabolisms.
This correlation has also been observed in the natural world, where animals that have high metabolic rates tend to have shorter lifespans than those with lower rates. The latter category also ages faster, when compared to members of their own, respective species.
Even with this example in mind, scientists have had a hard time showing that the same correlation holds true in humans as well, until now. In this investigation, experts sought to determine the influence of several factors on natural mortality rates.
The team focused primarily on each participant's energy expenditure, and how this factor could be used to predict natural mortality. Each test subject had his or her metabolic rates measured inside a metabolic chamber, for a period of 24 hours.
Investigators covered the cases of 652 non-diabetic Pima Indians. Of them, 508 had their 24-hour energy expenditure measured, whereas about 384 only had their rest metabolism assessed.
“We found that a higher endogenous metabolic rate, that is, how much energy the body uses for normal body functions, is a risk factor for earlier mortality,” explains scientist Reiner Jumpertz, MD.
“This increased metabolic rate may lead to earlier organ damage (in effect accelerated aging) possibly by accumulation of toxic substances produced with the increase in energy turnover,” he goes on to say.
“It is important to note that these data do not apply to exercise-related energy expenditure,” added Jumpertz. “This activity (exercise) clearly has beneficial effects on human health,” adds the expert, who was also the lead author of the new study.
Rest metabolic rates were measured once every 15.4 years, between 1982 and 2006. Total energy expenditure was monitored once every 11.1 years, between 1985 and 2006. During the study period, 27 test subjects succumbed to natural cases.
“The results of this study may help us understand some of the underlying mechanisms of human aging and indicate why reductions in metabolic rate, for instance via low calorie diets, appear to be beneficial for human health,” concludes Jumpertz, quoted by PsychCentral.