As a child we all learn that our body temperature is 37 degrees Celsius, but that is not entirely true. Our temperature has gradually cooled in the last 150 years, probably to an average of around 36.6 ° C. American researchers discovered this, believing that the decrease is related to our improved living conditions.
First of all, it is already a misunderstanding that body temperature is the same for everyone and at all times. For example, women have a slightly higher temperature than men and your body temperature also drops slightly as you get older. In addition, weight plays a role, just like the moment of the day.
Cooled to 36.6 ° C
Regarding human average body temperature, a recent study of 25,000 British patients already stated that 36.6 ° C is probably a better estimate than 37 ° C. The 37 ° C standard dates from the 1850s and is based on research by the German doctor Carl Wunderlich. The American scientists at Stanford University now confirm that we have, as it were, cooled down.
The researchers analyzed data measured between 1860 and 1940, 1971 and 1975 and 2007 and 2017. It turned out that the average temperature of Americans went down by 0.03 ° C per decade. A man today therefore has a temperature that is about 0.59 ° C lower than its counterpart in the early 19th century. For women, such early data was not available, but it was found that their temperature had fallen by 0.32 ° C since the 1890s.
Better living conditions
The researchers were unable to determine with certainty why we are cooling down, but they did put forward different hypotheses. They generally link the decrease to a lowered metabolic rate, so a reduced amount of energy that we use for our metabolism or metabolism.
This reduction is probably due to the fact that we suffer less from chronic inflammation, thanks to medical progress and an increased standard of living. Because such inflammations produce all kinds of proteins that boost your metabolism and increase your temperature.
Another possibility is that our comfortable lives in a constant ambient temperature contribute to a reduction in our metabolic rate. In the 19th century, houses had irregular heating and no cooling systems, now central heating and air conditioning are standard. A more stable environment eliminates the need to spend energy on maintaining a constant body temperature.
Physiologically changed
"The environment in which we live has changed, including the contact with microorganisms and the food we have available," explained senior author Julie Parsonnet. "All these things mean that we are now physiologically simply different from how we were in the past." The downward trend shows no signs of stopping, according to Parsonnet. "There is a limit, but I don't know where it is."
