Life's Greatest Miracle Hero

(This program is no longer available for online streaming.) A sequel to one of the most popular NOVAs of all time, &quot;Miracle of Life,&quot; this Emmy Award-winning program tracks human development from embryo to newborn using the extraordinary microimagery of Swedish photographer Lennart Nilsson.

Trace human development from embryo to newborn through the stunning microimagery of photographer Lennart Nilsson.

Life's Greatest Miracle

Poisoned Water Hero

Water. Turn on the faucet and it’s always there. Without it we perish. But how safe is our tap water? In this special report narrated by Joe Morton, NOVA investigates what happened in Flint, Michigan, when local officials changed the city’s water source to save money, but overlooked a critical treatment process. As the water pipes corroded, lead leached into the system, exposing the community—including thousands of children—to dangerous levels of poison. NOVA uncovers the science behind this manmade disaster— from the intricacies of water chemistry to the biology of lead poisoning to the misuse of science itself. NOVA follows ordinary citizens and independent scientists who exposed the danger lurking in Flint’s water and confronted those who turned a blind eye. And discover the disturbing truth that reaches far beyond Flint—water systems across the country are similarly vulnerable. How can we protect ourselves from poisoned water? (Premiered May 31, 2017)

What exactly went wrong in Flint—and what does it mean for the rest of the country?

Poisoned Water

NOVA Wonders What's Living in You? Hero

Whether they make you fat, fart, or freak out, microbes play a central role in your life. Right beneath your nose—on your face, in your gut, and everywhere in between—trillions of bacteria, viruses, and fungi are so abundant in your body, they outnumber your human cells. But these aren’t just nasty hitch-hikers. Many are crucial to your survival. Evidence suggests that a diverse microbiome can keep you healthy and, conversely, a damaged one could kill you. NOVA Wonders peers into this microscopic world to discover the fascinating, bizarre, and downright surprising secrets of the human microbiome, including the world’s largest stool bank, which transforms raw stool into life-saving poop pills.

Discover how a world of microbes living in and on you can make you sick-and keep you healthy.

What's Living in You?

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Body & Brain

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Draper

The coronavirus has unleashed global havoc. Learn how scientists are hitting back.
Scientists are trying new, revolutionary techniques to make a SARS-CoV-2 vaccine, but face challenges along the way.
Can Scientists Use RNA to Create a Coronavirus Vaccine?Published: April 16, 2020Jennifer Haller: I’m the first person in the United States to receive the experimental coronavirus vaccine.Neal Browning: I was the second person to enter into COVID-19 trial vaccination.Haller: I was just looking for something to do to help.Browning: I said, “If this can bring closure to this pandemic and save lives in the process, I absolutely need to do this.”Narrator: The coronavirus has unleashed global havoc. A tiny virus with a vicious punch.How can we hit back?Akiko Iwasaki: Vaccines will be the savior in this entire pandemic.Rhiju Das: The idea is to teach our immune systems to take out the coronavirus before the virus takes over our body.Narrator: There are dozens of efforts underway to make a vaccine against SARS-CoV-2, the virus that causes COVID-19. A handful are using traditional methods, which use killed or weakened versions of all or part of the virus to get our immune system ready to fight. But some are trying a radically new approach.Das: There’s a new game in town that allows for even faster turnaround in developing and testing and then deploying vaccines. And it’s called an RNA vaccine. RNA, which is a kind of ancient cousin of DNA. RNA molecules are the scripts that viruses use and that our human bodies also use to make proteins.Narrator: The coronavirus’ RNA codes for at least 24 proteins, including its spike protein, which covers the exterior.Angela Rasmussen: It’s the protein that makes the coronaviruses have the crown appearance that they’re named after.Narrator: SARS-CoV-2 uses this protein to bind to and enter our cells, where it then injects its RNA, hijacking those cells to make lots more virus.Das: It’s almost like a skeleton key for a lock, opening a portal within human cells that the virus can slip in.Iwasaki: So if we can block that process, if you can neutralize the virus before even it enters the cell, that will be probably the Achilles heel that we need to target.Das: We can tell our body, “Hey, if you see anything with that kind of skeleton key shape, then just destroy it.”Narrator: This is where an RNA vaccine comes in, which becomes possible when you have a genetic sequence of the virus, and you know which genes code for which proteins.Das: So the concept of an RNA vaccine is: Let’s inject the RNA molecule that encodes for the spike protein.Rasmussen: It’s making your cell effectively do the work of creating this viral protein that is going to be recognized by your immune system and trigger the development of these antibodies.Das: Our bodies won’t make a full-fledged infectious virus. They’ll just make a little piece and then learn to recognize it and then get ready to destroy the virus if it then later comes and invades us.Iwasaki: The advantage of the RNA vaccine is that it can be produced within a matter of days. So these types of vaccines are much faster to generate.Das: Much faster than it takes, for example, to even prepare a flu shot for this seasonal flu strain. But on the other hand, it’s a relatively new, unproven technology. And there’s still no example of an RNA vaccine that’s been deployed worldwide in the way that we need for the coronavirus.Rasmussen: There is the possibility for unforeseen, adverse effects.Iwasaki: So this is all new territory. Whether it would elicit protective, robust immune response against this virus is just unknown right now.Narrator: In addition, RNA molecules have a weakness.Das: Here’s the dirty secret. They are ephemeral. They’re like the Snapchat of molecules. Like literally our bodies make an RNA script and destroy it a few minutes later once they use it as a little temporary instruction manual to make proteins.And so here’s the issue: If we make a bunch of these RNA vaccines and keep them in the fridge, if you wait a couple of days, they’re no longer good vaccines. Their expiration date is like a couple of days after you make them. And they have to be kept at a temperature of -80°C, which is super cold.This is a big deal breaker. We’ll have to find a way to stabilize the RNA so they’re refrigerator safe. And no one has quite figured out how to do that. And that is actually the problem that I’m involved in.Narrator: Das is optimistic.Das: I think we’re going to have a vaccine.Narrator: But it’s too soon to tell which approach will get us the vaccine we need. Traditional techniques may yet win the race.Iwasaki: Right now, I wouldn’t rule anything out because we just need a really good vaccine against this virus. I think the best approach is a multi-pronged approach where multiple vaccines are tried for efficacy and safety.Rasmussen: And I’m hopeful that there will be a lot of public support and really public will to continue working on some of these things so that we’re more protected and more prepared for the next pathogen that might emerge.Narrator: And in the midst of the current pandemic, it takes all kinds of people pitching in to get us to the other side.Haller: The piece that I played here really does pale in comparison to the sacrifices that others are making right now.Browning: It’s not heroic to sit down and get an injection in your arm. What’s heroic are the people who are on the front lines exposing themselves to try and save lives every day. That’s what heroism is.

The coronavirus has unleashed global havoc. Learn how scientists are hitting back.

Can Scientists Use RNA to Create a Coronavirus Vaccine?

What is COVID-19 and should you be worried?
Here’s what you need to know about the SARS-CoV-2 virus and the disease it causes, called COVID-19.UPDATE:At <a href="https://www.youtube.com/watch?v=Bvv33CGFJKM&amp;t=144s">2:24</a> the video states, “So far, evidence suggests that this coronavirus is spreading mostly from people who do feel sick, traveling from person to person in tiny droplets.” However, multiple preliminary studies have since suggested that the virus can spread from infected people who have not developed symptoms: <a href="https://www.youtube.com/redirect?v=Bvv33CGFJKM&amp;event=video_description&amp;q=https%3A%2F%2Fbit.ly%2F2w4R7iI&amp;redir_token=B0dEEiIOj4GXZvrIVOlROMqQ2AJ8MTU4NTg1ODExOUAxNTg1NzcxNzE5">https://bit.ly/2w4R7iI</a>, <a href="https://www.youtube.com/redirect?v=Bvv33CGFJKM&amp;event=video_description&amp;q=https%3A%2F%2Fbit.ly%2F2R6eakG&amp;redir_token=B0dEEiIOj4GXZvrIVOlROMqQ2AJ8MTU4NTg1ODExOUAxNTg1NzcxNzE5">https://bit.ly/2R6eakG</a>, <a href="https://www.youtube.com/redirect?v=Bvv33CGFJKM&amp;event=video_description&amp;q=https%3A%2F%2Fbit.ly%2F2UAqtru&amp;redir_token=B0dEEiIOj4GXZvrIVOlROMqQ2AJ8MTU4NTg1ODExOUAxNTg1NzcxNzE5">https://bit.ly/2UAqtru</a>.At <a href="https://www.youtube.com/watch?v=Bvv33CGFJKM&amp;t=162s">2:42</a> William Hanage says, “It’s not yet clear how long these droplets can survive on surfaces.” A study published in the New England Journal of Medicine on March 17, 2020, showed that SARS-CoV-2, the virus that causes COVID-19, can remain viable in aerosols for three hours, on copper for up to four hours, on cardboard for up to 24 hours, and on plastic and stainless steel for up to two to three days: <a href="https://www.youtube.com/redirect?v=Bvv33CGFJKM&amp;event=video_description&amp;q=https%3A%2F%2Fbit.ly%2F2R3jhSK&amp;redir_token=B0dEEiIOj4GXZvrIVOlROMqQ2AJ8MTU4NTg1ODExOUAxNTg1NzcxNzE5">https://bit.ly/2R3jhSK</a>.
What We Know and Don’t Know about the CoronavirusPublished: March 10, 2020Onscreen: There are hundreds of known coronaviruses that can infect birds and mammals. We know of 7 that have infected humans.Amira Roess: Coronaviruses all belong to the same family, and we call them coronaviruses because if you look at the outside structure of the virus, they look like crowns. And in Latin, “corona” means crown.Alok Patel: This is why it got its name. It&#x27;s not named after the beer.Onscreen: The official name for the coronavirus causing the epidemic today is SARS CoV-2—a coronavirus that&#x27;s never been seen in humans before. It can cause a respiratory illness called Coronavirus 2019, or COVID-19, with flu-like symptoms.William Hanage: The first two major symptoms observed in the majority of cases are a dry cough and fever.Onscreen: Another potential symptom is shortness of breath. Sometimes the infection becomes severe and can even be fatal.Roess: Individuals with underlying respiratory conditions, like asthma or tuberculosis or some other respiratory illness, are more prone to getting a severe infection from COVID-19.Patel: The data’s showing that the elderly or people with other medical conditions are at most risk of getting severe illness or dying.Onscreen: It&#x27;s not clear yet why some people get sicker than others. Not everyone who gets severely ill has an underlying condition.Roess: We&#x27;re constantly analyzing the data to understand who is most at risk for dying from COVID-19. Onscreen: One group of people has not gotten very sick.Patel: Children are not getting as severe of infections with this coronavirus.Onscreen: And the reasons for that are not clear. Among the adults known to be infected, the majority of cases so far have been mild. But we don&#x27;t yet know the exact percentage.Hanage: At present there is still a lot of uncertainty as to how much of the disease is comparatively mild. So, if it is mostly comparatively mild, that sounds like it&#x27;s good—but actually it comes with a kicker, which is it&#x27;s much more difficult to control.Onscreen: That&#x27;s because if infected people don&#x27;t feel very sick, they&#x27;re more likely to go to school, to work, to the store, to a theater, where they can spread the virus.So far, evidence suggests that this coronavirus is spreading mostly from people who feel sick, traveling from person to person in tiny droplets.Hanage: Droplets are the small little sort of blobs of fluids that we emit when we cough or sneeze or even talk.Onscreen: Droplets can also be passed from hands to surfaces.Hanage: It&#x27;s not clear how long this virus can survive on surfaces, but it could survive for quite a long time.Onscreen: Other coronaviruses have survived up to nine days.If you touch that surface and then touch your nose, mouth, or eyes, the virus can get into your body and cause infection.Will the virus spread less when the weather turns warmer?Hanage: There is virtually no evidence that the coming change in the seasons will help at all. China has really quite varied climatic conditions—from very humid places like Hong Kong in the South to parts of the North, which are much colder and less humid—and they found virtually no difference. I also note that it&#x27;s been transmitting quite well in Singapore and Singapore is on the equator. So, this suggests that different climatic conditions are not going to have a major impact.Onscreen: There&#x27;s still a lot researchers don&#x27;t know about COVID-19, including how many people have been exposed or infected.Epidemiologists like William Hanage would like to see a serological survey that examines blood samples to assess whether a person has been exposed.Hanage: If you have those data then you have be going to be able to be much, much more precise about how many people were exposed, how many people got infected, how many had mild disease, how many of the children became infected, whether or not there is actually a different attack rate across the different age cohorts.All of that at the moment is mostly speculation. But with this, we&#x27;d be able to actually say something sensible about how lethal it is.Onscreen: In the meantime, people can take steps to reduce their risk of getting COVID-19.Hanage: People should be aware that this is an extremely serious situation. They should also not feel helpless. It&#x27;s not a time to panic, but it is a time to prepare and there&#x27;s a bunch of stuff that we can all do which will make us much less likely to get infected—and if we&#x27;re less likely to get infected, we&#x27;re less likely to transmit it to our communities and other people, including our loved ones.Onscreen: Protect yourself from those droplets that could carry the coronavirus. Stay away from people who are sick, if you can.Patel: A lot of people out there clamoring to go and buy masks. If you&#x27;re healthy and you have no symptoms, and you are not around other people who may be sick, you don&#x27;t need to go out and buy a mask. Now, if you are sick, wearing the correct type of mask may prevent you from spreading the disease to other people.Onscreen: Keep your hands clean.Patel: What people need to do is follow really strict hygiene precautions and that includes washing your hands either 20 seconds with soap and water or with hand sanitizer, making sure that you are not touching your eyes and your nose.Roess: We recommend eating a healthy diet, lots of fresh fruits and vegetables, stay hydrated, get plenty of rest and sleep. That is really important for boosting your immune system and helping your body fight pathogens before they make you sick.Hanage: Even if we cannot keep the virus out forever, we can still slow it down. And every moment we can slow it down buys us time, makes less stress on health care, and enables us to hopefully get to the point when we&#x27;re going to be able to move past this.

What is COVID-19 and should you be worried?

What We Know and Don’t Know about the Coronavirus

Learn the science behind the tests.
What goes on inside those test tubes to detect whether a person is positive for SARS-CoV-2, the virus that causes COVID-19?
How Coronavirus Tests WorkPublished: March 27, 2020Nurse: All right, all done.Yeah, it’s awful. I’m sorry. I wish there was a better way to do it.  Are you OK?Shelby Anderson: Yeah.It was quite painful, not gonna lie. You know like when you get a shot and it kinda like, pinches a little bit? It was like that in your nose.Sarah Epps: The doctor comes to your car and asks you a bunch of questions, does a physical exam with a stethoscope and everything, and then does the swab and sends you on your way and that’s it.It felt like you were snorting really spicy mustard up one nostril, it was quite a shock.Narrator: This is how most coronavirus tests are done in the U.S.John Connor: So you stick a swab into somebody’s nose and you pull it out. And what&#x27;s on it? You have some of your cells. You have potentially, virus.Narrator: To find out if the virus is on that swab, scientists use a process known as polymerase chain reaction, PCR.David Price: It’s basically just a way of taking a small amount of nucleic acids, RNA specifically for this virus and turning it into a lot of nucleic acid so that you can detect it Narrator: The new coronavirus contains RNA—a single strand of genetic information that sits inside a spherical casing.Connor: So the first thing you have to do is to get into that genome. So after this swab, what you will then do is take what was on that swab and blow everything apart. Narrator: Chemicals are added to isolate any genetic material.Pride: And then you take that tube and you subject it to a PCR.Narrator: Pieces of genetic material—called primers—are added to the tube. Connor: So, the primers are those small pieces of DNA that are going and looking for the genomic RNA. And if the genomic RNA is there, those primers will bind and that binding makes a landing site for the enzyme to make that new copy. Narrator: This happens over and over again—creating millions of copies.Connor: As that new copy is made, now you get fluorescent molecules coming in and binding to that new copy.  Narrator: So if that snippet of coronavirus genetic material is present, PCR will make lots of copies, and fluorescent molecules will make them glow. That glow means patient is infected.In February, the CDC sent out test kits for this PCR process, but some of the chemicals didn’t work properly.Pride: What happens is that for every test you run a negative control, which is a sample that&#x27;s supposed to be negative that also tells you if the test is working. If your negative control is positive, the whole thing you&#x27;ve got to throw in the trash, basically.  So, what was happening with the CDC tests is that there was a lot of false positives particularly in the negative control and that was due to the impurities in the kits.Narrator: In March, the FDA loosened regulations, allowing labs and commercial testing facilities to use their own tests.Pride: So that&#x27;s that&#x27;s really sort of a significant step and that&#x27;s what allowed us to go live with the test.Narrator: Now there are more challenges.Pride: Even just getting materials to extract the RNA from the virus is a problem right now. Every step of the way, we are experiencing bottlenecks.Narrator: Shortages of protective gear limit health care workers’ ability to safely take samples. And shortages of test kits and crucial chemicals limit labs’ ability to test the samples for the virus. Pride: So every day when I come into work, the first thing I do is start getting on the phone, getting on my emails, trying to secure additional supplies the kits themselves, all of the testing materials. We&#x27;re basically using all our materials much, much faster than we would like to. Narrator: Most PCR tests are run on machines at specialized labs that process many samples at once. Some labs are able to share results quickly.Anderson: I had mine in 18 hours.Narrator: Shelby says her test came back negative.Anderson: No, I don’t have it.Narrator: Some results have taken several days.Epps: I’m still waiting for my test results. Narrator: Sarah reports her results came back an entire week after her test, and were also negative.Some new tests can be done much faster—in less than an hour—but these will likely be used primarily for patients in hospitals and some health care workers.The FDA is warning against new at-home coronavirus tests, calling them “fraudulent.” A completely different kind of test is being developed to detect the virus by looking for antibodies.Connor: Our immune system goes into a very nice adaptive response where it will identify the infecting virus and make antibodies that have very high affinity against it. And those are effective at blocking further infection.Narrator: An antibody test could not only identify who’s been infected, but also identify who may have immunity.Connor: Those could be people that are very important in our response to the disease. If they already have an immune system that has seen the virus and has developed an effective response against it, they might be people that can help individuals that do need assistance when they are sick. Narrator: Scientists are optimistic about improving capacity to test for the virus using methods currently in use. Connor: I am optimistic about the coming weeks. I think we will get to the point where we understand this virus. We have the diagnostic capacity.Pride: As multiple different companies are approved and they ramp up their production, we should eventually be able to meet the need. The question is, is that two weeks from now or is that six weeks from now? That&#x27;s the harder part to answer.

Learn the science behind the tests.

How Coronavirus Tests Work

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 <div class="rich-text">Hello, NOVA fans! We understand that many of you may be spending more quality time at home than usual. And, as schools across the country remain closed, fostering student learning at home is a top priority.In the upcoming weeks, we’ll be sharing collections of some of our favorite NOVA films—all organized by subject to make bingeing, learning, and entertainment as easy as possible for science lovers of all ages.Whether you&#x27;ve ever been curious about the microscopic world of organisms living inside you or wanted a deeper understanding of the science of addiction, get ready: The subject of this collection is “Health and Medicine.”<h3><a href="https://www.pbs.org/wgbh/nova/video/decoding-covid-19/">Decoding COVID-19 (2020)</a></h3></div>
 

 
 

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 <div class="rich-text">The coronavirus SARS-CoV-2 has upended life as we know it in a matter of mere months. But at the same time, an unprecedented global effort to understand and contain the virus—and find a treatment for the disease it causes—is underway. Join the doctors on the front lines of the fight against COVID-19 as they strategize to stop the spread, and meet the researchers racing to develop treatments and vaccines. Along the way, discover how this devastating disease emerged, what it does to the human body, and why it exploded into a pandemic.<h3><a href="https://www.pbs.org/wgbh/nova/video/addiction/">Addiction (2018)</a></h3></div>
 

 
 

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 <div class="rich-text">Hear firsthand from individuals struggling with addiction and follow the cutting-edge work of doctors and scientists as they investigate why addiction is not a moral failing, but a chronic, treatable medical condition. Easy access to drugs like heroin, fentanyl, and even prescription medications like OxyContin has fueled an epidemic of addiction—the deadliest in U.S. history. Now, science is revealing how addiction affects the brain, and top experts are gathering evidence about how we should address our drug problem, from embracing evidence-based treatments, to rethinking public policies.<h3><a href="https://www.pbs.org/wgbh/nova/video/poisoned-water/">Poisoned Water (2017)</a></h3></div>
 

 
 

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 <div class="rich-text">Water. Turn on the faucet and it’s always there. Without it we perish. But how safe is our tap water?In this special report narrated by Joe Morton, NOVA investigates what happened in Flint, Michigan, when local officials changed the city’s water source to save money, but overlooked a critical treatment process. As the water pipes corroded, lead leached into the system, exposing the community—including thousands of children—to dangerous levels of poison. NOVA uncovers the science behind this manmade disaster— from the intricacies of water chemistry to the biology of lead poisoning to the misuse of science itself. NOVA follows ordinary citizens and independent scientists who exposed the danger lurking in Flint’s water and confronted those who turned a blind eye. And discover the disturbing truth that reaches far beyond Flint—water systems across the country are similarly vulnerable. How can we protect ourselves from poisoned water?<h3><a href="https://www.pbs.org/wgbh/nova/video/vaccinescalling-the-shots/">Vaccines—Calling the Shots (2014)</a></h3></div>
 

 
 

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 <div class="rich-text">Whether they make you fat, fart, or freak out, microbes play a central role in your life.Right beneath your nose—on your face, in your gut, and everywhere in between—trillions of bacteria, viruses, and fungi are so abundant in your body, they outnumber your human cells. But these aren’t just nasty hitch-hikers. Many are crucial to your survival. Evidence suggests that a diverse microbiome can keep you healthy and, conversely, a damaged one could kill you. NOVA Wonders peers into this microscopic world to discover the fascinating, bizarre, and downright surprising secrets of the human microbiome, including the world’s largest stool bank, which transforms raw stool into life-saving poop pills.<h3><a href="https://www.pbs.org/wgbh/nova/video/lifes-greatest-miracle/">Life&#x27;s Greatest Miracle (2001)</a></h3></div>
 

 
 

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 <div class="rich-text">A sequel to one of the most popular NOVAs of all time, &quot;Miracle of Life,&quot; this Emmy Award-winning program tracks human development from embryo to newborn using the extraordinary microimagery of Swedish photographer Lennart Nilsson.</div>
 

 
 <div class="newsletter"></div>

Six episodes exploring the fascinating science and innovations in health and medicine.

NOVA Marathons: Health & Medicine

The discovery of leptin transformed our view of fat.
A young man with lipodystrophy receives treatment after researchers find a hormone in mice that helps regulate appetite in humans.
How the Hormone Leptin Helps Regulate AppetitePublished: April 23, 2020Narrator: Troy Fryer has less than two percent body fat. Although he looks extremely fit, it’s the of lack fat that makes his muscles stand out. With no padding on his face, his cheeks look sunken and his eyes are deeply set.Jason Simon-Fryer: How far are you off that way?Troy Fryer: The little bit of fat on my body is behind my eyeballs and on my liver, so walking around not having fat, it feels like constant needles are poking through the bottom of your shoe.Jason Simon-Fryer: You know, some stand up all day and are okay with it; Troy is not. Because he has no padding on his feet, nothing in between his knees, there’s no comfort at all. It’s just unbelievable to watch him struggle.Narrator: Troy was born with a normal amount of fat. But by age six, he began rapidly losing weight, despite having a voracious appetite.Troy Fryer: I would go through two or three loaves of bread in one day, making 10 sandwiches at a time. So, I would keep eating and eating and eating, until it would hurt. And if I didn’t get that food, I would get really upset and really angry. I would rip doors off their hinges.Jason Simon-Fryer: I actually sent him in for a psych evaluation, thinking that there was something wrong, because he couldn’t take the answer “No.” It’s like he was starving.Narrator: By age nine, Troy was clearly ill. Doctors were shocked to find that his blood was full of fat and cholesterol, symptoms typical of obesity. It made no sense, until Troy was diagnosed with a genetic disease called lipodystrophy.Elif A. Oral: We always think about thinness as something good, but, in generalized lipodystrophy, it’s beyond thinness. It’s actually, absolute lack of fat under the skin, so, the excess energy doesn’t have a place to go.Narrator: And that’s why Troy was sick. With no fat tissue, excess calories collected in his liver, enlarging and inflaming it.Jason Simon-Fryer: And when it got to that point of the doctor saying there’s nothing else we could do for you, Troy turned to the doctor and said, “So how and when am I going to die?”Narrator: Salvation would come from the discovery of a mouse that also couldn’t stop eating. But unlike Troy, this mouse was fat, not thin. A genetic mutant from a breeding experiment, it was nicknamed O.B. for obese.Jeffery Friedman: This mouse had a defect in a single gene. And the impact of that gene was a mouse that weighed three times normal and had five times as much fat and that overate voraciously. And genetics is very powerful, because what it tells you is that obesity has a biological basis. What that basis is required identifying the gene.Narrator: Scientists began to hunt for the mutation that made the mouse obese, combing through the 2.5-billion letters of its genome.Friedman: Think of it as an alphabet. You spell out letters of the genome. There are four letters, A, G, T and C. These spell out, indirectly, proteins, and a single spelling error can lead to a defective gene.Narrator: In 1994, after a decade of work, Friedman and his collaborators homed in on a gene only found in fat cells.Friedman: That was really the moment of a lifetime. I pulled out the film with some vague hope that maybe this would reveal something about the nature of the O.B. gene. And I looked at it. And in that instant, I knew that we had identified the gene that makes a hormone and that plays a very active role in regulating appetite, metabolism and probably other biological systems.Rudolph Leibel: So, if you injected that hormone into the blood of an O.B. mouse, the mouse lost weight. It would completely cure the mutation of a O.B. mouse.Friedman: And over the course of a few weeks, depending on the dose you give, they’ll look indistinguishable from a normal mouse.Narrator: The hormone was named “leptin,” from the Greek word leptos, meaning thin. Its discovery transformed our view of fat and the biological forces controlling appetite.Friedman: The O.B. mouse cannot see itself in a mirror and realize that it’s hugely obese. It thinks it’s starving to death, because this very critical hormone is not being made by the body. And the idea that a hormone produced by fat can control what you think about food in a very important way, this is a very radical notion.Narrator: A normal fat cell produces leptin, which travels to the brain and signals the hypothalamus, a region that determines when and how much we eat. High levels of leptin tell your brain you have plenty of fat stored, but low levels tigger an alarm to eat.And for those like Troy, who can’t make leptin because they lack fat, getting the hormone would be lifesaving.Jason Simon-Fryer: The starvation was gone within three days of him taking leptin. We saved a lot of money. Troy went from eating what three people would eat, to eating what a normal person would eat in a day.Troy Fryer: Knowing that I was full, I’m like, “Wow, this is amazing.”Narrator: Leptin can’t cure Troy’s disease, but by curbing his hunger, it protects his liver.Oral: Leptin does not bring the fat back. It just helps to deal with fat’s absence. Patients finally can take a deep breath that they’re full and they don’t have to worry about eating.

The discovery of leptin transformed our view of fat.

How the Hormone Leptin Helps Regulate Appetite

&quot;Blood Sugar Rising&quot; follows the diabetes epidemic in the U.S. Diabetes and pre-diabetes affect over 100 million people in the country, costing more than $325 billion each year. The documentary puts human faces to these statistics, exploring the history and science of the illness through portraits of Americans whose stories shape the film.

Blood Sugar Rising: America's Hidden Diabetes Epidemic

It has to do with where the fat is distributed in their bodies.
Experts weigh in on the relationship between food and exercise—turns out it&#x27;s much more complex than it seems.Remembering sumo champion Byambajav Ulambayar, who died in February 2020.
How Do Sumo Wrestlers Avoid Obesity-Related Diseases?Published: April 9, 2020Onscreen: The heavier you are in sumo, the harder it is to take you down. But how do sumo wrestlers avoid diseases normally associated with obesity? Narrator: The answer lies in where they store their fat: safely underneath their skin, instead of in the abdomen or chest, packed around internal organs.Stephen O&#x27;Rahilly: And so, if you do a scan of an active sumo wrestler or a C.T. scan or an M.R.I. scan, you’ll see all that fat. But it’s on the outside, it’s on the buttocks and thighs, it’s on the outside of the abdomen.Carolyn Apovian: So even though they have body fat, they don’t contain a lot of fat in those deleterious places such as the liver, around the heart, around the pancreas and even around the kidneys. So, they’re metabolically healthy.Narrator: And the key reason is that sumo wrestlers exercise rigorously, up to seven hours a day.Sylvia Tara: When we exercise, our fat releases a hormone called adiponectin, and adiponectin actually helps guide fats in the blood into safe deposits of fat, so they’ll guide it into subcutaneous fat, right under the skin.Interestingly, when sumo wrestlers come off of their exercise regime, they get metabolically unhealthy very quickly.Narrator: To maintain a stable weight, the number of calories you eat needs to match the number you burn. So, many assume that losing weight is simply a matter of eating less and exercising more. But scientists are discovering that it’s not so simple.O&#x27;Rahilly: So, what is astonishing is the fact that we ingest more than a million calories a year. And yet we don’t oscillate between supermodel and an opera diva over the whole period of a year. We stay pretty stable.Randy Seeley: So, I think the best way to think about how weight is regulated is to think of it as a set point, right? That is, that our body is defending a very particular weight under a certain set of circumstances.Rudolph Leibel: And it’s obviously not set, because the body weight can change. What is set is what is the minimum body weight for that individual. If you drop your body weight below this threshold, the body will begin to do whatever it has to do, to prevent your dying of starvation.

It has to do with where the fat is distributed in their bodies.

Topic: Body & Brain

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