By Kennedy Shelley
You usually only find out your body temperature when something is wrong. You want to know if you have a fever.
But for some strange reason, the average temperature is going down, and now doctors are re-evaluating what normal is.
We were all taught in school that normal is 98.6 degrees Fahrenheit.
Santorio in 1612 came up with the first rudimentary thermometer with a scale on it, but it was not found to be really useful.
Taking your temperature as part of a medical exam started in 1867 when Sir Thomas Allbutt came up with a practical 6-inch thermometer that could record your temperature in 5 minutes.
The technology has only gotten better. Now we can scan someone across the room in less than a second.
What is interesting about this latest research into average body temperatures is that it can tell us much more than if we have a fever or an infection, it might provide a good mirror into our overall metabolic health.
To get our average a German physician measured the temperature of a village of 25,000 people, and found the average was 37 C.
But last year, scientists in the UK checked the temperature of 35,000 and took over 250,000 measurements, only to find this has dropped to 36.6 C.
One of the startling questions raised by the team was:
“the differences observed in temperature between the 19th century and today are real and that the change over time provides important physiologic clues to alterations in human health and longevity since the Industrial Revolution.”
The study was published in eLIFE Sciences.
We are getting colder at a rate of .03 C per decade. What does this mean for our species?
Body temperature is a crude marker for our basal metabolic rate. That is the rate that we burn calories when we are resting.
Slow basal metabolic rates mean you burn fat less efficiently. Conversely, losing weight through calorie restriction will also lead to a decrease in basal metabolism.
A study of The Biggest Loser Contests show that this change might be permanent and is a reason why people often gain more weight after a diet. See this article in Freedom Health News for more information.
Men are .59 C cooler than men a century ago and women .32 C.
Why is this happening? Several reasons are suggested:
- We control our environment more with central heating and air conditioning 24/7.
- We are not as exposed to bacteria as much as we used to. We are cleaner and our immune system is not ramped up as much.
- Our diet is different, less animal fat and more processed foods.
So, with our basic drop in metabolic rates, we could expect some increase in our weight because we are not burning as many calories as our great grandparents.
The scientists are not saying that we need to change the scale of what is considered normal, but it may be a warning sign that something is happening to people.
What was normal for our ancestors, may not be normal today.