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Average human body temperature mysteriously declined, finds study
A new study seeks to understand why the average body temperature is no longer 98.6 degrees Fahrenheit.
- Average human body temperatures have declined, show several studies.
- A new paper looked at an indigenous population in the Amazon over 16 years.
- They found the new body temperature of the observed people to be 97.7°F, not the standard 98.6°F.
Temperature checks have become part of the new normal in the world under Covid, but the average body temperature may not be what the thermometers say. A series of studies, including a new paper, propose that the average human body temperature has been dropping for decades and is currently much lower than the accepted 98.6 degrees Fahrenheit, in fact, closer to 97.5°F.
The established standard for how warm your body should be came from the 19th century German physician Carl Wunderlich, whose 1851 measurement of 98.6°F set the bar for a long time. A 2017 study, however, that looked at 35,000 UK adults, found 97.9°F to be the average. A 2019 study measured 97.5°F as the normal temperature for Americans in Palo Alto, California.
Now, a team of physicians looked at the temperatures of the Tsimane, an indigenous people of the Bolivian Amazon, and discovered a comparable decrease. Observations over a 16-year-period revealed that the temperatures of the Tsimane went down about 0.09°F per year. Today, they are at about 97.7°F.
Michael Gurven, professor of anthropology from UC Santa Barbara, who led the research, commented that "in less than two decades we're seeing about the same level of decline as that observed in the U.S. over approximately two centuries."
The large study involved 18,000 observations of 5,500 adults and adjusted for factors that could have affected the body heat like outside temperature or body mass. They also used the same type of thermometer throughout, to make sure the instrument wasn't the issue.
Adjusting for various factors, they sought to figure out the reason for the decrease which was consistently noticed. They conjectured that fewer infections as a result of better hygiene, cleaner conditions, vaccinations, and improved medical treatments were possibly responsible for their find.
While such possibilities are there, they did not account fully for the observations. Chances are, a combination of influences is responsible for the lower temps. "Declines might be due to the rise of modern health care and lower rates of lingering mild infections now as compared to the past," Gurven shared. "But while health has generally improved over the past two decades, infections are still widespread in rural Bolivia. Our results suggest that reduced infection alone can't explain the observed body temperature declines."
Some additional explanations offered by Gurven include the fact that we now have better anti-inflammatory drugs and even the advancements in air conditioning.
"While Tsimane body temperatures do change with time of year and weather patterns, the Tsimane still do not use any advanced technology for helping to regulate their body temperature," Gurven explained. "They do, however, have more access to clothes and blankets."
It should be noted that the study looked at average temperatures, and physicians do not think there is truly one temperature that everyone should have. What's considered "normal" is really a range of temperatures that depends on the individual. Still, the information is valuable in pointing to the population's overall health.
Check out the new paper in Sciences Advances.
- Psychogenic shivers: why we get the chills when we aren't cold ... ›
- It's cold! A physiologist explains how to keep your body feeling warm ›
The COVID-19 pandemic is making health disparities in the United States crystal clear. It is a clarion call for health care systems to double their efforts in vulnerable communities.
- The COVID-19 pandemic has exacerbated America's health disparities, widening the divide between the haves and have nots.
- Studies show disparities in wealth, race, and online access have disproportionately harmed underserved U.S. communities during the pandemic.
- To begin curing this social aliment, health systems like Northwell Health are establishing relationships of trust in these communities so that the post-COVID world looks different than the pre-COVID one.
COVID-19 deepens U.S. health disparities<p>Communities on the pernicious side of America's health disparities have their unique histories, environments, and social structures. They are spread across the United States, but they all have one thing in common.</p><p>"There is one common divide in American communities, and that is poverty," said <a href="https://www.northwell.edu/about/leadership/debbie-salas-lopez" target="_blank">Debbie Salas-Lopez, MD, MPH</a>, senior vice president of community and population health at Northwell Health. "That is the undercurrent that manifests poor health, poor health outcomes, or poor health prognoses for future wellbeing."</p><p>Social determinants have far-reaching effects on health, and poor communities have unfavorable social determinants. To pick one of many examples, <a href="https://www.npr.org/2020/09/27/913612554/a-crisis-within-a-crisis-food-insecurity-and-covid-19" target="_blank" rel="noopener noreferrer">food insecurity</a> reduces access to quality food, leading to poor health and communal endemics of chronic medical conditions. The U.S. Centers for Disease Control and Prevention has identified some of these conditions, such as obesity and Type 2 diabetes, as increasing the risk of developing a severe case of coronavirus.</p><p>The pandemic didn't create poverty or food insecurity, but it exacerbated both, and the results have been catastrophic. A study published this summer in the <em><a href="https://link.springer.com/article/10.1007/s11606-020-05971-3" target="_blank">Journal of General Internal Medicine</a></em> suggested that "social factors such as income inequality may explain why some parts of the USA are hit harder by the COVID-19 pandemic than others."</p><p>That's not to say better-off families in the U.S. weren't harmed. A <a href="https://voxeu.org/article/poverty-inequality-and-covid-19-us" target="_blank" rel="noopener noreferrer">paper from the Centre for Economic Policy Research</a> noted that families in counties with a higher median income experienced adjustment costs associated with the pandemic—for example, lowering income-earning interactions to align with social distancing policies. However, the paper found that the costs of social distancing were much greater for poorer families, who cannot easily alter their living circumstances, which often include more individuals living in one home and a reliance on mass transit to reach work and grocery stores. They are also disproportionately represented in essential jobs, such as retail, transportation, and health care, where maintaining physical distance can be all but impossible.</p><p>The paper also cited a positive correlation between higher income inequality and higher rates of coronavirus infection. "Our interpretation is that poorer people are less able to protect themselves, which leads them to different choices—they face a steeper trade-off between their health and their economic welfare in the context of the threats posed by COVID-19," the authors wrote.</p><p>"There are so many pandemics that this pandemic has exacerbated," Dr. Salas-Lopez noted.</p><p>One example is the health-wealth gap. The mental stressors of maintaining a low socioeconomic status, especially in the face of extreme affluence, can have a physically degrading impact on health. <a href="https://www.scientificamerican.com/index.cfm/_api/render/file/?method=inline&fileID=123ECD96-EF81-46F6-983D2AE9A45FA354" target="_blank" rel="noopener noreferrer">Writing on this gap</a>, Robert Sapolsky, professor of biology and neurology at Stanford University, notes that socioeconomic stressors can increase blood pressure, reduce insulin response, increase chronic inflammation, and impair the prefrontal cortex and other brain functions through anxiety, depression, and cognitive load. </p><p>"Thus, from the macro level of entire body systems to the micro level of individual chromosomes, poverty finds a way to produce wear and tear," Sapolsky writes. "It is outrageous that if children are born into the wrong family, they will be predisposed toward poor health by the time they start to learn the alphabet."</p>Research on the economic and mental health fallout of COVID-19 is showing two things: That unemployment is hitting <a href="https://www.pewsocialtrends.org/2020/09/24/economic-fallout-from-covid-19-continues-to-hit-lower-income-americans-the-hardest/" target="_blank" rel="noopener noreferrer">low-income and young Americans</a> most during the pandemic, potentially widening the health-wealth gap further; and that the pandemic not only exacerbates mental health stressors, but is doing so at clinically relevant levels. As <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7413844/" target="_blank" rel="noopener noreferrer">the authors of one review</a> wrote, the pandemic's effects on mental health is itself an international public health priority.
Working to close the health gap<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDc5MDk1MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxNTYyMzQzMn0.KSFpXH7yHYrfVPtfgcxZqAHHYzCnC2bFxwSrJqBbH4I/img.jpg?width=980" id="b40e2" class="rm-shortcode" data-rm-shortcode-id="1b9035370ab7b02a0dc00758e494412b" data-rm-shortcode-name="rebelmouse-image" />
Northwell Health coronavirus testing center at Greater Springfield Community Church.
Credit: Northwell Health<p>Novel coronavirus may spread and infect indiscriminately, but pre-existing conditions, environmental stressors, and a lack of access to care and resources increase the risk of infection. These social determinants make the pandemic more dangerous, and erode communities' and families' abilities to heal from health crises that pre-date the pandemic.</p><p>How do we eliminate these divides? Dr. Salas-Lopez says the first step is recognition. "We have to open our eyes to see the suffering around us," she said. "Northwell has not shied away from that."</p><p>"We are steadfast in improving health outcomes for our vulnerable and underrepresented communities that have suffered because of the prevalence of chronic disease, a problem that led to the disproportionately higher death rate among African-Americans and Latinos during the COVID-19 pandemic," said Michael Dowling, Northwell's president and CEO. "We are committed to using every tool at our disposal—as a provider of health care, employer, purchaser and investor—to combat disparities and ensure the <a href="https://www.northwell.edu/education-and-resources/community-engagement/center-for-equity-of-care" target="_blank" rel="noopener noreferrer">equity of care</a> that everyone deserves." </p><p>With the need recognized, Dr. Salas-Lopez calls for health care systems to travel upstream and be proactive in those hard-hit communities. This requires health care systems to play a strong role, but not a unilateral one. They must build <a href="https://www.northwell.edu/news/insights/faith-based-leaders-are-the-key-to-improving-community-health" target="_blank" rel="noopener noreferrer">partnerships with leaders in those communities</a> and utilize those to ensure relationships last beyond the current crisis. </p><p>"We must meet with community leaders and talk to them to get their perspective on what they believe the community needs are and should be for the future. Together, we can co-create a plan to measurably improve [community] health and also to be ready for whatever comes next," she said.</p><p>Northwell has built relationships with local faith-based and community organizations in underserved communities of color. Those partnerships enabled Northwell to test more than 65,000 people across the metro New York region. The health system also offered education on coronavirus and precautions to curb its spread.</p><p>These initiatives began the process of building trust—trust that Northwell has counted on to return to these communities to administer flu vaccines to prepare for what experts fear may be a difficult flu season.</p><p>While Northwell has begun building bridges across the divides of the New York area, much will still need to be done to cure U.S. health care overall. There is hope that the COVID pandemic will awaken us to the deep disparities in the US.</p><p>"COVID has changed our world. We have to seize this opportunity, this pandemic, this crisis to do better," Dr. Salas-Lopez said. "Provide better care. Provide better health. Be better partners. Be better community citizens. And treat each other with respect and dignity.</p><p>"We need to find ways to unify this country because we're all human beings. We're all created equal, and we believe that health is one of those important rights."</p>
A study by UK archaeologists finds that longbows caused horrific injuries similar to modern gunshot wounds.
- UK archaeologists discover medieval longbows caused injuries similar to modern gunshot wounds.
- The damage was caused by the arrows spinning clockwise.
- No longbows from medieval times survived until our times.
Battle of Agincourt.
The angle of entry into a cranium found during the excavation at a medieval Dominican friary in Exeter, England.
Credit: Oliver Creighton/University of Exeter
Never made a turkey before? Don't worry, science can help.
- This year, many people will be making a Thanksgiving dinner for the first time. It's often harder than it looks.
- Luckily, an online calculator website has one just for thawing turkey, and can explain why you need to wait so long.
- The website has other calculators as well, for needs you didn't know you had.
How to thaw a turkey using science!<p> The Omni Calculator <a href="https://www.omnicalculator.com/" target="_blank" rel="noopener noreferrer">website</a> is home to calculators that can determine many things, including how <a href="https://www.omnicalculator.com/other/sunscreen" target="_blank" rel="noopener noreferrer">long you can be in the sun safely</a>,<a href="https://www.omnicalculator.com/other/sunscreen" target="_blank" rel="noopener noreferrer"> </a>to the odds of your town having a <a href="https://www.omnicalculator.com/other/white-christmas" target="_blank" rel="noopener noreferrer">white Christmas</a>. It now has a dedicated tool for finding how long it will take you to prep your <a href="https://www.omnicalculator.com/food/turkey-thawing" target="_blank" rel="noopener noreferrer">turkey</a> in time for a socially distanced holiday. The <a href="https://www.omnicalculator.com/food/turkey-thawing" target="_blank">Turkey Thawing Calculator </a>was created by Jagiellonian University cognitive science graduate Maria Kluziak with the help of Wojciech Sas, a Ph.D. candidate in molecular magnetism and nanostructures at the Institute of Nuclear Physics in Poland. </p><p>The fundamental problem is that you need to add heat to the frozen bird to unfreeze it without also encouraging the growth of bacteria. To do this, you have to put the turkey somewhere where it will heat up slowly and evenly. There is a trick, though; this can take a long time because of the amount of energy involved. Exactly how long you need to spend on it can be hard to determine if you've never done it before. </p><p>This is where practical, day-to-day science comes in. The processes of heating something are well-studied areas of thermodynamics which we use every day. <br> <br> As Kluziak tells Big Think: </p><p>"If you look closely, you'll notice how we're all surrounded by numbers. Yet most of the time people choose to go with their intuition while making day-to-day decisions. We, as scientists and experts in our own fields, are trying to build a world where people make better, more informed decisions backed by concrete science - Using physics to chill drinks, math to find out how much pizza to get, and even calculating how much groceries are enough to survive a quarantine. It works."</p>
So, how do I thaw a turkey?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDgwNjA0Ny9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY0NzI3NTQzN30.hr2xv0tzFU_12bA-wwKwBPv0Tou_ZcdMoF1VDlov-0k/img.png?width=980" id="07afc" class="rm-shortcode" data-rm-shortcode-id="522a8b8370fecb9dcb3bf483adea6fa5" data-rm-shortcode-name="rebelmouse-image" />
Credit: Omni Calculator<p> By slowly exposing the turkey to cool air or water, it heats up to a point where the bird is above freezing but not so warm that bacteria will start multiplying. Two of the safe ways to do this stand above all others; you can thaw it in the refrigerator or the sink.<br> <br> Using a refrigerator can take days; the calculator creators suggest a day for every four pounds of bird. Doing it with cold water in the sink is faster, needing only two hours per pound, but requires that you drain and refill the sink with new, cold water every thirty minutes. The ideal temperature during thawing shouldn't exceed 39°F/4°C.</p><p>"In our thawing model, we use a scientific approach, which is based on the use of heat transfer equations," the scientists write. "Since these types of problems are, in general, very complicated, we use some approximations, which allow us to estimate the thawing time with reasonable accuracy. As a result, you can see how the average temperature of the turkey changes in time." </p><p>You can learn more about the equations and get tips on using the calculator <a href="https://www.omnicalculator.com/food/turkey-thawing" target="_blank" rel="noopener noreferrer">here</a>. You can also learn why you shouldn't use a hairdryer or a tub full of hot water to do the job. <br> <br> One of the best parts of science is that its findings are often universally applicable. If you understand why something works in one case, you can use it everywhere else. Kluziak reminds us why this might be great for cooking:<br> <br> "The rules that govern the process of thawing are roughly the same for every kind of food, what's different are the numbers that determine the more specific things like thawing time. The general ideas remain the same regardless of the food, and I would say they are pure common sense. For example, if you're defrosting food, don't do it at room temperature to avoid bacteria - this is true every time!"<strong></strong></p><p><strong> </strong>Whoever said you'd never use the science you learned in high school at home didn't understand how often we use physics—this calculator remind us that it is everywhere. So fear not, ye first-time turkey chefs! Science can help you have your main course and eat it too. </p>
These tiny fish are helping scientists understand how the human brain processes sound.
- Fragile X syndrome is a genetic disorder caused by changes in a gene that scientists call the "fragile X mental retardation 1 (FMR1)" gene. People who have FXS or autism often struggle with sensitivity to sound.
- According to the research team, FXS is caused by the disruption of a gene. By disrupting that same gene in zebrafish larvae, they can examine the effects and begin to understand more about this disrupted gene in the human brain.
- Using the zebrafish, Dr. Constantin and the team were able to gather insights into which parts of the brain are used to process sensory information.
By disrupting a specific gene in Zebrafish, we're able to better understand the same disruption of that gene in humans with FXS or autism.
Credit: slowmotiongli on Adobe Stock<p>"Loud noises often cause sensory overload and anxiety in people with autism and Fragile X syndrome -- sensitivity to sound is common to both conditions," <a href="https://www.sciencedaily.com/releases/2020/11/201110102527.htm" target="_blank">Dr. Constantin explained to Science Daily</a>.</p><p><strong>How do zebrafish relate to humans with autism? </strong></p><p>According to the research team, FXS is caused by the disruption of a gene. By disrupting that same gene in zebrafish larvae, they can examine the effects and begin to understand more about this disrupted gene in the human brain. </p><p>The thalamus, according to Dr. Constantin, works as a control center, relaying sensory information from around the body to different parts of the brain. The hindbrain then coordinates different behavioral responses. Using the different sound tests, the team was able to study the whole brain of the zebrafish larvae under microscopes and see the activity of each brain cell individually. </p><p>According to Dr. Constantin, the research team recorded the brain activity of zebrafish larvae while showing them movies or exposing them to bursts of sound. The movies stimulated movement, a reaction to the visual stimuli that was the same for fish with the Fragile X mutation and those without. However, when the fish were given a burst of white noise, there was a dramatic difference in the brain activity of the fish with the Fragile X mutation.<br></p><p>After seeing how the noise radically affected the fish brain, the team designed a range of 12 different volumes of sound and found the Fragile X model fish could hear much quieter volumes than the control fish. </p><p>"The fish with Fragile X mutations had more connections between different regions of their brain and their responses to the sounds were more plentiful in the hindbrain and thalamus," <a href="https://www.sciencedaily.com/releases/2020/11/201110102527.htm" target="_blank">said Dr. Constantin</a>.</p><p>Essentially, the fish with Fragile X mutation had more connections between the regions of their brain and so their responses to the sounds were more notable. </p><p><strong>Understanding how this gene disruption works in zebrafish will give us a better understanding of sound hypersensitivity in humans with FXS or autism.</strong> </p><p>"How our neural pathways develop and respond to the stimulation of our senses gives us insights into which parts of the brain are used and how sensory information is processed," Dr. Constantin said.</p><p>Using the zebrafish, Dr. Constantin and the team were able to gather insights into which parts of the brain are used to process sensory information. </p><p>"We hope that by discovering fundamental information about how the brain processes sound, we will gain further insights into the sensory challenges faced by people with Fragile X syndrome and autism."</p>