We got colder. Literally. At least that’s what a study in eLife is defending this month. Stanford University researchers have analyzed the body temperature of the American population in three different periods over the past 150 years.
677,423 total temperatures medical records (including civil war data) have indicated that the average temperature of today’s men is 0.59 ° C lower than that born in the early 19th century, while in women this figure has dropped to 0.32 ° C. The previous temperature measurement of 37 ° C would no longer be standard.
The scientific community is partially divided. Philip Mackowiak, co-author of a 1992 body temperature study, states that the number of variables that could have influenced the study (such as changes in temperature over the centuries) from mouth to arm) may have affected the results, although the original authors claim to have taken measures to correct these possible variances in the sample. On the other hand, there are those who point out that there is no body temperature per se, but a temperature range that depends on the test subjects. According to Stanford, this has also already been taken into account.
What those who support this theory say: Michael Gurven, an anthropologist at the University of California, said he studied the temperatures of the Tsimané indigenous community in 2016 draw similar conclusions: Between 2004 and 2018, the average temperature of society fell in these years in a similar ratio as in the current study, which he believes should be taken seriously.
How is it possible that the temperature has dropped? Although Stanford’s study does not provide any conclusions, it does provide theories. First and foremost, it’s about improving living conditions and reducing infectious diseases. People have given up the infection rates that we presented a decade ago in areas such as syphilis, tuberculosis and gum disease.
But it could also affect the decrease in our metabolic rate (the energy we need to function) thanks to the thermal conditions under which men have grown in advanced societies over the past few decades: we are more protected, we have heaters and air conditioners, This means that the body has to put up less resistance to its surroundings.
When we add the possible impact of sedentary life and the greater availability of healthy food, we face the challenge one of the so-called epigenetic changes, That is, the environment has caused our timing to change, and this could affect the expression of certain genes, such as those related to our immune system.
Does that mean we now get sick at a lower temperature? No. If something they point out from different positions is that, although the average temperature had dropped, the standard of what we should consider as fever should remain intact, at 37.7 ° C.