A new study published in the journal eLife has demonstrated something that has long been suspected: the average human body temperature has been decreasing over the past 150 years. While 37°C has been considered the normal human body temperature since the 1860s, discrepancies observed in more recent studies had hinted that the accepted value was incorrect.
This new study analyzed a sample of 677,423 human body temperature measurements covering a period of 157 years. Based on this data, the researchers were able to demonstrate that the average human body temperature has decreased by approximately 1.6% since the pre-industrial era.
The discrepancy between the accepted value and more recent observations was often attributed to limitations in the equipment used by scientists over a century ago. However, the data from this study demonstrate that the change in measurements is the direct result of physiological changes. The authors suggest that several factors could have produced this change in body temperature measurements. Most importantly, they believe that the level of inflammation in the general population has likely decreased since the 19th century due to improved standards of living and sanitation, better dental hygiene, and lower incidences of major communicable diseases such as tuberculosis.
While the long-term effects of such a change in body temperature are unknown, the confirmation that human body temperature has changed over a relatively short period of time suggests that our lifestyles can affect our bodies in very subtle but important ways.
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