Being cool: how body temperature influences ageing and longevity

Abstract

Temperature is a basic and essential property of any physical system, including living systems. Even modest variations in temperature can have profound effects on organisms, and it has long been thought that as metabolism increases at higher temperatures so should rates of ageing. Here, we review the literature on how temperature affects longevity, ageing and life history traits. From poikilotherms to homeotherms, there is a clear trend for lower temperature being associated with longer lifespans both in wild populations and in laboratory conditions. Many life-extending manipulations in rodents, such as caloric restriction, also decrease core body temperature. Nonetheless, an inverse relationship between temperature and lifespan can be obscured or reversed, especially when the range of body temperatures is small as in homeotherms. An example is observed in humans: women appear to have a slightly higher body temperature and yet live longer than men. The mechanisms involved in the relationship between temperature and longevity also appear to be less direct than once thought with neuroendocrine processes possibly mediating complex physiological responses to temperature changes. Lastly, we discuss species differences in longevity in mammals and how this relates to body temperature and argue that the low temperature of the long-lived naked mole-rat possibly contributes to its exceptional longevity.

Fig. 1

A schematic diagram of predicted body temperature influences on longevity in poikilotherms (top panel) and homeotherms (bottom panel). Only qualitative differences between poikilotherms and homeotherms are shown, as axes are not quantitative. Away from thermal extremes, longevity predicted by metabolic rate (Gillooly et al. 2001) declines exponentially with increased body temperature

Fig. 2

A schematic diagram of the age-specific mortality rates of male D. melanogaster which had undergone CR or been fed ad libitum (top panel) and at either 27 or 18 °C ambient temperatures (bottom panel). Adapted from (Mair et al. 2003)