What does the average American body temperature mean by falling year by year?

According to foreign media reports, 37 degrees Celsius is an important number.
clinically and medical textbooks, 37 degrees Celsius is considered the "normal" average temperature of the human body.
but a new study suggests that the average body temperature in the United States has now declined, and researchers think they may know why.
the average temperature measurement 1851, a doctor in the German city of Leipzig named Carl Reinhold August Wunderlich set a temperature of 37 degrees Celsius (98.6 degrees Fahrenheit) for the first time after collecting body temperature information from about 2,500 people.
", he took the temperature of the person he could find, whether they were healthy or not, and wrote a book about the link between body temperature and disease.
" study's senior fellow, Dr. Parsonett, a professor of medicine and health research and policy at Stanford University.
Julie Parsonnet).
Windrich's study also highlights changes in body temperature in different genders, ages, weights and heights, "his conclusions are almost entirely correct, and he must have spent a lot of time studying these body temperature data."
"Since Windrich did this pioneering work, doctors have still used body temperature as one of the key markers of determining a person's health."
Now we know that body temperature fluctuates up to 0.2C in a day, young people tend to have a higher body temperature than the elderly, and women's body temperature is usually higher than that of men, depending on the menstrual cycle.
, body temperature is also affected by weather, physical activity and eating.
, but why does human body temperature generally fluctuate around 37 degrees? There is evidence that the body maintains body temperature at a relatively stable level in order to ensure the smooth functioning of many organs and chemical reactions in the body, as well as to prevent fungal infections.
But the ideal body temperature may no longer be 37 degrees Celsius, according to a new study published on January 7.
average body temperature in the United States has been falling since the early 19th century, about 0.02 degrees Celsius every 10 years.
the average body temperature of an American male born in the 21st century was 0.58 degrees Celsius lower than that of an American man in the early 19th century, and a 21st-century American woman's body temperature was 0.32 degrees Celsius lower than that of a woman born in the 1890s.
question, why does this happen? As an infection researcher, Parsonnett spent years studying a bacterial infection caused by Helicobacter pylori.
Helicobacter pylori can cause esophagus, stomach and small intestine ulcers and increase the risk of stomach cancer.
however, the infection rate of Helicobacter pylori in the United States has declined in recent years. "I've been studying Helicobacter pylori for 30 years, so I know very fewer and fewer people in the U.S. infected with it, "
.
" this change reflects a larger trend: modern humans are much less likely to develop infectious diseases than those who lived in the 19th century.
19th century people may experience a series of problems such as malaria, chronic wounds, tuberculosis, dental disease, dysentery, but these bacteria are rare in modern human sons, so the immune system does not need to be overloaded at all times.
and Parsonet wanted to find out how the decline in microbes in the body is gradually altering the body's physiology.
, together with the study's co-authors, she analyzed a large amount of data, including data sets from the American Civil War, the 1970s and early 2000s, with a total of more than 677,000 temperature records.
found that the average human temperature has been declining for years.
to rule out the interference of the temperature monitor from the data, the researchers also analyzed trends within each data set.
results showed that there was a downward trend in body temperature in each data group, regardless of the thermometer used.
"Humans have evolved over the years, and the physiology has changed a lot."
" Parsonett points out, "modern humans have a lower body temperature than humans in the 19th century and the last century."
"Why is this important?" The findings echo those of a 2017 study in the UK.
the British study analysed 250,000 body temperature records from more than 35,000 patients and found that the average body temperature in the UK was 36.6degree Degrees, down from the "normal" average of 37 degrees.
it seems that human body temperature is indeed declining, but what does it mean for human physiology? Mr Parsonnet said it remained an open mystery. "We haven't yet figured out how hypothermia affects people's health and longevity, "
.
" lower body temperature may reflect a decrease in the prevalence of infection.
this trend significantly reduces the incidence of inflammation in the body.
inflammation produces a protein called cytokines, which speed up the body's metabolic rate and generate heat.
Besides, unlike our ancestors, many people now live in temperature-controlled environments.
"We don't have to struggle to keep our body temperature constant because the temperature in the room is always in the 20s."
"Of course, the temperature of residents in other countries may be very different from that in britain and the United States.
for example, a 2008 study found that the average body temperature of a Pakistani national still fluctuates around 37 degrees Celsius.
but small differences in body temperature in different groups do not affect the physiological function of the body.
this may affect the function of microorganisms in the body, but we don't know much about it.
," Mr Parsonnett said.
personally, only drastic changes in body temperature represent health problems such as fever or hypothermia.
and overall, with advances in medicine and longer life expectancy, average body temperature may continue to decline.
Parsennett also noted that body temperature is "an indication of the level of inflammation in the body."
if you can measure the average of a group, it may be possible to predict its life expectancy.
", she added, that life expectancy and body temperature may flatten out in the future and remain the same for a long time.
Source: Sina Technology Leaf.