Your Body Keeps Producing Cannabis-Like Chemicals Throughout a Marathon

09 Sept. 2026, By E. Öz

https://www.sciencealert.com/your-body-keeps-producing-cannabis-like-chemicals-throughout-a-marathon

(RUN 4 FFWPU/Pexels/Canva)

Running a marathon is hard. Luckily, your body has its own chemical support system to help it cope.

As the kilometers pass, the body produces more natural messengers called endocannabinoids. These help regulate pain, stress, mood, energy use, and recovery.

Endocannabinoids are a normal and useful part of the body. Their rise may help it adapt to physical strain, but more is not automatically better.

Despite their name, endocannabinoids are not cannabis, and the body is not producing a drug.

The brain is packed with cannabinoid receptors – and if you think of them as locks, endocannabinoids are the body's keys.

Cannabis compounds, including THC, can fit some of the same locks, which is why these natural chemicals are sometimes described as "cannabis-like."

Endocannabinoids may contribute to the famous "runner's high": the happiness, calm, reduced anxiety, and dulled pain some people experience during long runs.

This feeling was once credited to endorphins. But they do not readily cross the barrier between the blood and brain, leading researchers to rethink the familiar explanation.

Most human studies have tracked exercise-related endocannabinoids for less than an hour. In a new BMC Medicine study, researchers investigated what happens when people run for several hours or longer.

Researchers collected blood samples from ultramarathon runners completing distances of up to 230 kilometers. (Courtesy of Katrin Ringe and Michael Siebers (Marathonstudie and TTdR3))



First author and psychiatrist Michael Siebers of the University of Duisburg-Essen in Germany and colleagues conducted two field studies with experienced endurance runners.

In the first, 19 participants completed a marathon around Lake Baldeney in Essen, Germany. On another day, the same people walked for exactly as long as they had run.

Blood was collected before the marathon, during two brief stops mid-marathon, again at the finish, and finally after 45 minutes of rest. Participants rated their happiness, anxiety, and pain.

The researchers tracked a number of different endocannabinoids in the runners' bodies, including two well-known ones that seem to be related to the runner's high: anandamide and 2-AG.

Anandamide takes its name from ananda, the Sanskrit word for bliss – and it lived up to that name. As the participants ran, the amount in their blood steadily increased. From 14 kilometers (8.7 miles) onward, levels were significantly higher than during the matched walk and remained elevated 45 minutes after the finish.

The second messenger, 2-AG, is thought to have broader roles in immune regulation, inflammation, energy use, and tissue recovery. It behaved differently, rising near the end of the marathon and remaining elevated during recovery.

"Anandamide and 2-AG are produced and degraded through different biochemical pathways, so it is not surprising that they followed different time courses," Siebers told ScienceAlert.

Previous research has linked anandamide more consistently with mood and features of the runner's high. The later rise in 2-AG may instead reflect the body's efforts to manage inflammation, energy demands, and recovery.

However, Siebers cautioned that this remains a hypothesis. The two messengers have overlapping functions, and scientists cannot yet give each one a separate job.

The runners' feelings changed too. Compared with walking, marathon running was associated with greater happiness and lower anxiety. Pain, however, increased significantly after 28 kilometers of running.

Participants provided repeated blood samples during the endurance-running study. (Courtesy of Katrin Ringe and Michael Siebers (Marathonstudie and TTdR3))



The second field study involved 36 experienced athletes running 100, 160, or an astonishing 230 kilometers in the TorTour de Ruhr ultramarathon. Blood samples were taken before and after.

Levels of both anandamide and 2-AG increased after all three distances. Surprisingly, longer did not necessarily mean more: levels of some endocannabinoids were higher after the standard marathon than after the ultramarathons.

Exercise intensity may matter more than duration alone. Ultramarathon runners usually move more slowly to conserve energy, while extreme fatigue, pain, and depleted energy stores may change the body's chemical response.

There was another puzzle. Although the ultramarathoners' endocannabinoid levels rose and their anxiety fell, their happiness did not increase significantly. Only 12 of the 36 reported a runner's high during the race.

"The runner's high is a difficult phenomenon to capture scientifically," Siebers said. "It is transient and highly individual – rather like trying to capture fog in a jar."

Because happiness was measured only before and after the ultramarathons, brief periods of runner's high may have been missed. Extreme fatigue and pain may also have drowned out any feeling of bliss.

"Elevated endocannabinoid levels alone are not sufficient to produce a runner's high," Siebers explained.

The study cannot prove that these chemicals caused the psychological changes, because they were measured in the blood rather than directly in the brain. A previous study in mice offered stronger evidence that cannabinoid receptors help reduce anxiety and pain after running, but the same causal link has not been demonstrated in humans.

The groups were also small, and factors such as sleep, food, and stress were not fully controlled.

Still, the findings provide an unusually detailed look at the chemical journey inside the body during real-world endurance running.

These natural messengers may provide happiness, calm, pain relief, or simply help the body endure the next kilometer. But their effects appear far more complicated than a simple runner's high.

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Belly Fat, Not Age, May Be The Bigger Driver of Low Testosterone

10 Sept. 2026, By C. Cassella

https://www.sciencealert.com/belly-fat-not-age-may-be-the-bigger-driver-of-low-testosterone

(kali9/E+/Getty Images)

Aging may not impact your testosterone levels as much as you might think.

From the age of about 35, studies suggest that circulating levels of this sex hormone in men usually begin to decline.

But it's only very gradual.

There's another overlooked factor that could have a bigger impact: where fat is stored in the body.

According to a new analysis, published in the Journal of the Endocrine Society, visceral fat, or deep fat in the abdomen, may be the more precise metabolic determinant of testosterone suppression.

This specific type of fatty tissue can wrap around vital organs like the liver, stomach, and intestines, and it has many receptors for testosterone, making it especially sensitive to this circulating hormone.

In a review of health data from nearly 5,000 men in the US, aged 20 to 59, the presence of visceral fat was strongly associated with testosterone suppression.

In fact, in this age bracket, it seemed to influence testosterone concentrations significantly more than chronological aging.

After accounting for fat distribution, age showed only modest associations within the study's age range.

The two review authors, research physiologists Karl Friedl and Adam Potter, of the US Army Research Institute of Environmental Medicine, conclude that deep belly fat should be the "primary adiposity correlate of low testosterone in US men".

Visceral adipose tissue area and total testosterone in US men aged 20–59 years, adjusted for age and body mass index (BMI). (Friedl & Potter, Journal of the Endocrine Society, 2026)



Previous research has similarly found that among middle-aged men, fat-related measures exert a greater influence on testosterone levels than age.

For instance, a 2007 study of 1,667 men found that gaining 4 to 5 body mass index (BMI) points was linked to a decline in testosterone, and this was comparable to roughly 10 years of aging.

Such results also broadly align with research from 2013, which tracked 1,382 men over the course of five years.

The study authors concluded that age-related declines in T levels are "not inevitable", but instead are explained by smoking behavior and health status, particularly obesity and depression.

But using BMI to measure obesity also has its flaws.

Today, BMI and waist circumference remain the most common measures of excess body weight, but they aren't necessarily the best measures of cardiometabolic health.

While obesity is largely consistent with lower testosterone levels, men with similar BMIs and waist circumferences can still demonstrate substantially different levels of this hormone.

It's possible, for instance, that a young man with a BMI in a healthy weight range has a high percentage of hidden visceral fat, and this may be impacting his testosterone levels.

By contrast, an older, muscular man with lower visceral fat could be deemed to have a higher risk of testosterone issues just because of his age and BMI score.

In cases like these, visceral fat levels may be the more important consideration.

It's unclear why testosterone production is so closely linked to visceral fat, but researchers have a few ideas.

Deep fat in the abdomen can promote insulin resistance, and this, in turn, may cause a downstream impact on how certain cells in the testes convert cholesterol to testosterone.

Visceral fat can also stimulate inflammatory pathways that could disrupt the body's hormone signaling pathway, increasing the conversion of testosterone to estradiol.

"Current guidelines appropriately recognize obesity as a risk factor for low testosterone, but our findings suggest that adipose distribution, particularly visceral adiposity, may provide additional information beyond total body mass alone," explain Friedl and Potter.

This means that interventions that reduce visceral fat, including drugs like Ozempic or Wegovy, may address the issues of low testosterone more directly than testosterone replacement therapy alone.

"These observations underscore the importance of characterizing the underlying adiposity phenotype and considering reversible metabolic contributors before initiating testosterone therapy," the study authors conclude.

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Scientists Are Making Concrete With Human Poop – And It Gets 42% Stronger

09 Sept. 2026, By M, Starr
https://www.sciencealert.com/scientists-are-making-concrete-with-human-poop-and-it-gets-42-stronger

Could the concrete of the future contain a little bit of poop?

 (Lighthouse Films/Getty Images)

Concrete is, quite literally, the foundation of the modern world.

Almost every construction project in the world uses the material in some form. There's just one problem, and that's a big one: Making one of its central ingredients – cement – is horrendously bad for the environment.

The act of heating and processing limestone to make cement is one of the world's foremost sources of carbon dioxide emissions – so, understandably, scientists have been looking for ways to mitigate this problem.

And researchers led by civil engineer Raghuvesh Tiwari of Manipal University Jaipur in India may have just hit upon an ingenious solution that takes care of two environmental birds with one stone.

By mixing in biochar made from the human poop slurry processed at fecal sludge treatment plants, their concrete "yields significant improvements in concrete properties," they write in a paper accepted for publication in Scientific Reports.

Fecal-sludge biochar before (left) and after grinding and sieving for use in concrete. 

(Tiwari et al., Sci. Rep., 2026)



Concrete owes its extraordinary usefulness to a combination of properties. It's malleable when wet, and can be poured into almost any shape, yet cures into a material strong enough to support enormous loads and durable enough to last for decades (or millennia).

It's usually made from a few things in specific quantities: sand, gravel, water, and the cement itself – which is primarily made using limestone.

Unfortunately, that ingredient mix is finicky – altering the balance, or substituting some of the cement for something else, can produce concrete that is not as strong or durable as the real McCoy. It's not going to be very useful as a building material if it literally cracks under pressure.

One increasingly promising cement substitute is biochar, a carbon-rich material made by heating organic matter in an oxygen-poor environment.

The beauty of biochar is that it can be made from many kinds of organic matter.

And humans produce quite a large amount of organic matter – up to around 400 grams of poop per person per day, which isn't much on an individual level, but when you get several million people doing it, it's kind of astonishing that our sewers are as effective as they are.

Anyway, all those daily tons of poop have to go somewhere, which is where the dots start to connect.

In India, fecal sludge treatment plants have been established to safely manage human waste, which can be processed into biochar through pyrolysis – so the researchers figured, if sawdust, wood, rice husk, and other biochars are effective at making concrete, ¿por qué no los poop?

To put it to the test, Tiwari and his colleagues obtained fecal-sludge biochar from a treatment plant in Warangal, India.

To make the biochar, fecal sludge is dried, then heated in a low-oxygen environment at temperatures between 350 and 450 degrees Celsius (662 to 842 Fahrenheit) to produce biochar. The biochar is then ground and sieved into a fine powder.

The researchers used this powder to replace varying amounts of cement – 5, 10, and 15 percent – in conventional concrete, then subjected the resulting poopcrete to a battery of tests to see how well it held up.

The biochar concrete specimens being prepared and tested for compressive strength.

 (Tiwari et al., Sci. Rep., 2026)

And, incredibly, a little bit of poop made the concrete better.

The researchers measured the shrinkage, compressive strength, flexural strength, water absorption, and porosity of their different mixes, and this is where it got really interesting.

Overall, the strongest concrete was generally produced when 5 percent of the cement was replaced with poop biochar.

But the poopcrete had another interesting trick: It continued to gain substantial strength as it cured. The researchers report that after 91 days, the 5 percent mix had recorded average increases of 20 percent in compressive strength and 36 percent in flexural strength.

At 10 percent cement replacement, those increases were even larger: 21 percent for compressive strength and a whopping 42 percent for flexural strength.

Compressive strength of concrete containing different proportions of fecal-sludge biochar after 28, 56, and 91 days of curing.

 (Tiwari et al., Sci. Rep., 2026)

The poopcrete didn't appear to pay for its strength in some of the other properties the team tested.

At 5 percent, it generally absorbed less water and had lower porosity than conventional concrete, while its drying shrinkage was also lower. At 10 percent, its performance remained broadly comparable to ordinary concrete.

But there is – isn't there always? – such a thing as too much poop.

At 15 percent cement replacement, the concrete still grew stronger as it cured, but its overall strength lagged behind the 5- and 10-percent versions.

So why does adding a little poop make concrete stronger?

The researchers think several effects work together. For one, poop biochar is highly porous, riddled with tiny cavities that can soak up water and gradually release it as the concrete cures.

This effectively turns the biochar particles into tiny internal reservoirs, keeping water available for the chemical reactions that harden and strengthen the cement.

Under the microscope, the structure of concrete changes as increasing amounts of cement are replaced with biochar. From top left: 0, 5, 10, and 15 percent biochar. (Tiwari et al., Sci. Rep., 2026)

But the poop isn't just sitting there holding water.

The biochar is rich in silica, which can react with compounds produced as cement cures to form more of the calcium silicates that help give concrete its strength.

In other words, it's pozzolanic – the same broad class of chemical reactions famously exploited in ancient Roman concrete, just with, well, human feces instead of the volcanic material the Romans used.

Finally, the fine biochar particles can fill gaps in the concrete and improve the way its ingredients pack and bond together.

The researchers could actually see the result under a microscope. Concrete containing 5 percent biochar had a denser, more tightly bonded structure than conventional concrete.

But at 15 percent, that structure began to deteriorate, with more pores, cracks, and poorly bonded regions appearing.

Now, we're not going to run out and start building skyscrapers out of poopcrete tomorrow. The researchers note that more work is needed to assess how it performs under real-world conditions, such as freeze-thaw cycles, salinity, and extreme temperatures.

There's also the matter of heavy metal accumulation, which is a known problem with sewage sludge. Locking potentially harmful heavy metals up in concrete could be a bonus, but it's not known how well they will stay locked up, or whether they will leach out over time.

The study also did not assess the impact of this method on carbon emissions.

However, replacing even a fraction of concrete's cement with a material made from a waste stream humans produce in inexhaustible quantities could potentially tackle two problems at once.

And if there's one thing we can rely on humans to produce in consistently large quantities, it's definitely poop.

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MIT Engineers Create a Living Circuit Board From Bacteria

By A. Trafton, Massachusetts Inst. of Tech., Sept. 8, 2026

https://scitechdaily.com/mit-engineers-create-a-living-circuit-board-from-bacteria/

MIT researchers have engineered bacteria that can function as transistors, allowing them to create “living circuit boards” like those shown. 

Credit: Courtesy of the researchers, edited by MIT News

MIT researchers have engineered bacteria to behave like transistors, making it possible to build living “circuit boards” that can be printed onto growth material in a Petri dish.

In conventional electronics, transistors act as switches that control whether electrical current flows. In the biological system developed at MIT, engineered bacteria perform a similar role by regulating the movement of small signaling molecules that carry information to other parts of the circuit.

The team created two types of bacterial transistors and three additional bacterial strains that act as relays between them. Together, those five strains provide a flexible toolkit that can be arranged into many different circuit designs. In their new study, the researchers used the system to build circuits capable of combining two or three inputs, as well as directing an incoming signal to a selected destination within the circuit.

“We’ve built some initial computer architecture components that are commonly used, but any operation can be built with these five strains,” says Hamid Doosthosseini PhD ’25, an MIT postdoc and the lead author of the new study.

Living Circuits Could Be Added to Plants

The researchers ultimately hope to create biological circuits that could be placed on plant leaves or roots. Those circuits could process information about changing environmental conditions, including drought or attacks by pests, and then help trigger an appropriate response.

Christopher Voigt, head of MIT’s Department of Biological Engineering, is the senior author of the paper, which was recently published in Nature Chemical Biology. Former MIT postdoc Haorong Chen is also an author of the paper.

Turning Cells Into Biological Transistors

Synthetic biology circuits are usually built by engineering cells to produce proteins and transcription factors that interact in specific ways. A circuit might, for example, detect a target molecule and then activate the production of a particular output.

These systems can perform several kinds of logic operations, but they face important limitations. To prevent unwanted interactions within a circuit, researchers generally need different transcription factors for different functions. Because only a limited number of suitable transcription factors are available, there is a ceiling on how complicated a circuit can become inside one cell. Packing too many circuits into a single cell can also strain the machinery the cell uses to make proteins.

The researchers created their circuits by printing colonies of bacteria onto plates containing agar, a growth medium. This GIF shows a time-lapse of the bacteria growing over 7 days. 

Credit: Courtesy of the researchers



The MIT team approached the problem differently. Rather than placing an entire circuit inside one cell, they engineered individual cells to work as transistor-like components. Those cells can then be arranged in different combinations to build a wider range of circuits.

For the transistors, the researchers used a bacterium called Pantoea agglomerans, which commonly grows on surfaces, including plants. They engineered two forms of the bacterial transistor, both controlled by a molecule called OC-6. One is switched on by OC-6, while the other is switched off.

Each transistor can also detect another molecule, OC-12. Depending on whether OC-12 is present and whether the transistor is active, the cell produces a signaling molecule known as OHC-14.

Wiring Bacterial Colonies Together

The team also engineered three strains of Pantoea agglomerans to act as biological relays. These strains convert the OHC-14 signal into a new output that can then be passed to another transistor. In this way, the researchers can “wire” bacterial components together in a manner similar to the layout of an electronic circuit board.

One possible arrangement is a bidirectional switch. Two transistors can detect OC-12 and then route that information toward different relay strains depending on a separate switch input. The signal can then move into additional transistors that continue processing the information.

To build the circuits physically, the researchers printed bacterial colonies onto plates containing agar, a growth medium. Neighboring colonies were placed about 5 millimeters apart.

That spacing is important because it limits how far each chemical signal can travel. A signal reaches only the nearest colony, which can then pass information to the next component. This creates a controlled path that allows information to move through the circuit in one direction.

Bacterial Circuits Perform Logic Operations

The researchers showed that a single transistor could carry out several kinds of logic operations depending on where it was positioned in the circuit, including “multi-input,” “or,” and “imply” gates.

They also combined transistors into more advanced systems. These circuits were able to add two signals, process larger numbers of signals at the same time, and function as a demultiplexer. A demultiplexer takes one incoming signal and directs it toward one of several possible outputs depending on a control signal.

The largest circuit demonstrated in the study contained 24 connected bacterial colonies and was designed to add two inputs together.

“This work shows that we can get toward more complicated functions by linking up simpler functions in individual cells,” Voigt says. “Computationally, there’s nothing that your iPhone can do that these circuits couldn’t do.”

Slow Computing With a Biological Purpose

These living circuits are dramatically slower than electronic computers. Each calculation takes about eight hours to complete.

For the kinds of biological applications the team has in mind, however, that speed may be more than adequate.

“We’re not trying to replace computers, but rather put computational control into biology. If you have bacteria on the root of a plant, or the plant itself is doing the computing, running a simple calculation overnight is fast enough relative to a growth season,” Voigt says.

In agriculture, such circuits might eventually be placed on plant roots to detect different forms of stress. When a particular signal is detected, the circuit could trigger a biological response, such as producing a fungicide.

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A Low-Plastic Diet Has Detectable Impacts on Urine Levels Within a Week, New Experiment Shows

09 Sept. 2026, By C. Cassella

https://www.sciencealert.com/a-new-study-put-people-on-a-low-plastic-diet-it-changed-the-chemicals-in-their-urine

(Kinga Krzeminska/Moment/Getty Images)

Plastic is virtually unavoidable in 2026, but there may be ways to reduce your exposure to some of its associated chemicals.

Two of the best places to start may be in the grocery store and the kitchen.

A randomized controlled trial involving 60 participants in Australia has found that using plastic-free kitchenware and buying food with minimal plastic contact may change what chemicals the body is exposed to.

After seven days of this particular, low-plastic intervention, the urine levels of three plastic-associated chemicals were up to 60 percent lower than in the control group.

The findings are published in Nature Medicine.

"Our results showed strictly adhering to a diet of food which has not touched plastic, whether that is during production or packaging, can reduce plastic chemicals in our body in as little as a week," says principal investigator and senior author Michaela Lucas, a clinical immunologist at the University of Western Australia.

"If this also carries major health benefits is something that's currently under further investigation."

(Theerawit Jirattawevut/iStock/Getty Images Plus)



Today, more than 16,000 chemicals are used to manufacture plastics, and some are known to be hormone disruptors in the human body with potentially hazardous effects.

In their study, Lucas and her colleagues examined two major types in particular: phthalates and bisphenols (BPA and BPS).

Phthalates are plasticizers that can migrate into our food from plastic packaging, plates, or utensils.

Bisphenols migrate into our food from the coating inside cans, as well as from food containers, cooking utensils, drink bottles, water pipes, and cling film.

"To date, little is known about the causal health effects of BPS; however, its use in certain food-contact materials has been regulated in the European Union," explain Lucas and her colleagues in the paper.

First, the research team considered the plastic exposure of 211 participants, and they found ubiquitous exposure to plastic-associated chemicals.

A hundred percent of participants excreted at least six plastic chemical metabolites on any given day.

Processed and packaged foods seemed to be important contributors.

Participants who had the lowest relative levels of plastic-associated chemicals rarely consumed fast food, highly processed foods, foods in plastic packaging, or microwaved foods in plastic.

To find out more, the research team ran a randomized trial involving 60 of the participants.

They wanted to determine if eating only foods that had been processed, stored, prepared, and consumed in glass, steel, or wood could reduce phthalate and bisphenol levels in the urine.

And in some cases, the trick worked. Not every chemical responded in the trial as scientists had hoped, but a few key ones did.

The five different groups in the experiment. 

(Harray et al., Nat. Med., 2026)

In the seven-day experiment, participants were either randomized to the control group or to one of four intervention groups.

These interventions included eating food produced, processed, packaged, and delivered with as little plastic contact as possible; eating low-plastic food without using plastic cooking equipment or utensils; using only low-plastic personal care products, such as shampoo; and a final combo of all three interventions.

Co-first author Amelia Harray says the team went to great lengths to minimize plastic exposure.

"Our dietitians worked with over 100 farmers and food producers to educate and transform their food handling processes and packaging to reduce plastic exposure from paddock to plate," Harray explains.

"Participants had access to any type of food they would usually consume – pasta, salads, meats, butter, chocolate, fruit, and snacks – which allowed energy intake to remain the same."

In the end, their rigor paid off.

While changes to personal care products had the least impact on plastic-associated chemicals in urine, a strict adherence to low-plastic foods had the best outcomes.

In the group given low-plastic food and kitchenware, mono-n-butyl phthalate levels were 38 percent lower, monobenzyl phthalate levels were 54 percent lower, and bisphenol A levels were 60 percent lower than the control group.

"By delivering participants low-plastic food and providing them with plastic-free kitchenware, such as stainless-steel pots, pans, kettles, toasters and wooden chopping boards, we showed that changing what you eat and how you prepare food could reduce plastic chemicals in the body," says Harray.

Both phthalates and bisphenols have short half-lives and are expected to be rapidly cleared from the body.

No one yet knows exactly what these chemicals may be doing to our long-term health.

But numerous epidemiological studies have found associations between these pollutants and health issues like cardiovascular disease, metabolic syndrome, and infertility.

Unfortunately, at this point we don't yet know what a 'safe' level of plastic in the body is.

If a health burden exists, however, it will likely increase over time unless we intervene. Plastic from the past is not going anywhere anytime soon, and plastic production is still on the rise to this day.

"This trial has delivered a message of hope that we can actively reduce plastic chemical levels in our bodies but is linked to significant changes in the way we produce and package our food," says Lucas.

It will take an effort, but the payoff may be worth it.

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Pomegranates Could Unlock a New Treatment for Heart Failure

By King's College London, Sept. 7, 2026

https://scitechdaily.com/pomegranates-could-unlock-a-new-treatment-for-heart-failure/

Researchers found that urolithin A improved relaxation in engineered human heart tissue and reduced several hallmarks of heart failure in laboratory models. 

Credit: Shutterstock

A compound produced in the body after eating pomegranates improved heart function by up to 80% in experimental models of a type of heart failure with limited treatment options.

For people with heart failure with preserved ejection fraction, the heart can still pump blood but struggles to relax and refill properly between beats. In experimental models of this difficult-to-treat condition, a naturally produced compound called urolithin A improved measures of heart function by as much as 80%.

Scientists at King’s College London found that urolithin A, which the body produces after people consume foods such as pomegranates, walnuts, and some berries, improved the heart’s ability to relax, reduced scarring, and limited harmful enlargement in experimental models.

The findings could ultimately be relevant to nearly half a million people in the UK who have heart failure with preserved ejection fraction. The condition accounts for about half of all heart failure cases and occurs when the heart retains its pumping ability but becomes too stiff to relax properly between beats, reducing how effectively it fills with blood. Symptoms can include breathlessness, fatigue, difficulty exercising, and poor quality of life.

A single engineered heart tissue attached to two posts. When the tissue contracts, the posts move back and forth. 

Credit: King’s College London



Treatment options remain relatively limited because the condition can arise from several different factors, including aging, high blood pressure, and diabetes. Since the heart can continue pumping normally while struggling to relax and fill, conventional heart failure treatments are less effective. Clinicians instead concentrate on managing underlying conditions and recommending lifestyle changes such as weight loss and blood sugar control.

Dr Joseph Burgoyne, senior author of the study, King’s College London, said: “This type of heart failure is becoming increasingly common as populations age and rates of obesity and diabetes rise. Despite its growing burden, treatment options remain limited because the disease is complex and varies considerably between patients.”

Engineered heart tissues each grown between fixed posts. 

Credit: King’s College London



Urolithin A activates a relaxation pathway

Interest in urolithin A has grown because the compound has been linked to healthy aging and mitochondrial function, the process through which cells generate energy.

Dr. Joseph Burgoyne. 

Credit: King’s College London

The researchers found for the first time that urolithin A activates a protein called PKGlα, which contributes to both blood vessel function and relaxation of heart muscle. The compound acts on a specific amino acid within the protein, triggering a pathway associated with cardiovascular benefits.

Heart function improved in experimental models

Animal models given urolithin A showed improvements of up to 80% in measures of heart function compared with untreated models. Laboratory testing also found that the compound helped heart tissue relax more effectively and reduced fibrosis, the harmful buildup of scar tissue. It also limited enlargement of heart muscle cells compared with controls, helping preserve normal cellular function.

The researchers then tested urolithin A in engineered human heart tissue made from human stem cells, a laboratory model designed to closely reproduce the structure and function of human heart muscle. Treatment significantly improved relaxation in this tissue, providing additional evidence that the effects could be relevant to human heart function.

Human trials are still needed

Urolithin A has already been evaluated in human studies and has shown a favorable safety profile, unlike many compounds that remain at an earlier experimental stage.

However, more research is required before these findings can be translated into treatment for patients. The results identify both a potential therapeutic target and a naturally derived compound that researchers can investigate further for this challenging form of heart failure.

Engineered heart tissues in a petri dish after being removed from the posts. 

Credit: King’s College London



Dr Joseph Burgoyne, senior author of the study, said: “This type of heart failure remains one of the most challenging forms of heart disease to treat. Our findings identify a completely new therapeutic target and show that urolithin A can activate this pathway to improve heart relaxation and reduce disease severity. This raises the exciting possibility of developing new treatments that improve clinical outcomes and quality of life for people living with the condition.

“While there isn’t enough evidence to suggest that people should eat pomegranates to treat heart failure, these findings raise the possibility that dietary approaches that enhance urolithin A production may help alleviate this condition.”

Dr Joseph Burgoyne is a cardiovascular scientist at King’s College London who studies the molecular processes that regulate heart and blood vessel health. His research examines how cells respond to oxidative stress and how those responses affect blood pressure, heart function, and vascular health, with the aim of identifying new treatments for conditions including hypertension and heart failure.

Engineered heart tissues with solution. 

Credit: King’s College London



Professor James Leiper, Director of Research at the British Heart Foundation, said: “Heart failure with preserved ejection fraction (HFpEF) makes up roughly half of all heart failure cases in the UK, and can be debilitating. This early-stage study in experimental models suggests that urolithin A may help to improve the heart tissue’s ability to relax and fill with blood between beats, reducing the harmful changes to the heart muscle seen in HFpEF.

“While these findings are promising, the benefits have so far been seen in animals and engineered human tissue, so clinical trials involving people are needed to test if this approach is effective for patients. In the meantime, a healthy, balanced diet remains one of the best ways to look after your heart. Eating plenty of fruit and vegetables is linked to better heart health, but it’s important to remember that no single food can prevent or treat heart disease on its own.”

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Scientists Find a Fungus That Could Protect The Body From Radiation

07 Sept. 2026, By P. Dockrill

https://www.sciencealert.com/scientists-find-a-fungus-that-could-protect-the-body-from-radiation

Mucor racemosus.

 (Oggogg/Wikimedia Commons/CC0 1.0)

Mold isn't typically something you want growing inside your body.

But in the case of Mucor racemosus, there may be compelling reasons to make an exception.

That's because this symbiotic fungus that lives inside the human gut appears capable of protecting us from radiation, according to a new study in PNAS.

It might sound a bit hard to believe, but this isn't the first time we've seen fungi doing weird things with radiation.

We know that there are different kinds of radiation-resistant fungi, including species that survive being blasted with up to 200 times the fatal human dose of X-rays.

There's also the funky world of radiotrophic fungi, which use radiation as an energy source – like the bizarre fungus living its best life in the radioactive remains of the Chernobyl Nuclear Power Plant.

M. racemosus has a different kind of parlor trick for radiation, but it's no less impressive.

In their research, a team of scientists from China found the fungus can confer protection from radiation to its host through a couple of different mechanisms, suggesting M. racemosus may be a beneficial presence in the gut.

In experiments with mice exposed to radiation, the researchers found that animals administered M. racemosus experienced less weight loss, inflammation, and oxidative stress than control mice that weren't given a fungal dose, suggesting M. racemosus provided the treated animals with a radioprotective effect.

This radioprotective effect was boosted when the researchers preadapted the fungus to the oxygen-poor conditions of the gut.

When germ-free mice (raised to be free of microorganisms) were administered the fungus, they too showed reduced markers of radiation damage compared to control animals, suggesting M. racemosus helps to protect against the harms of radiation independent of host microbiota.

"These results demonstrate that M. racemosus directly alleviates radiation-induced intestinal injury in mice," the researchers explain.

As for how M. racemosus achieves this, subsequent testing on irradiated intestinal cells and mice revealed three amino acids produced by the fungus that might explain its radioprotective effects – L-glutamic acid, L-aspartic acid, and DL-lysine.

According to the researchers, these three amino acids directly facilitate DNA repair and intestinal tissue recovery after radiation exposure.

But that's not the only way the fungus does its thing.

Another chemical produced by the fungus, called methylthioadenosine (MTA), plays an important radioprotective role too, even if it doesn't work directly to heal radiation damage like the three amino acids.

Instead, it seems that M. racemosus's MTA production modulates the growth of a bacterium called Limosilactobacillus reuteri and also reprograms it to increase production of a chemical called methionine, higher levels of which seem to boost radiation protection.

In a final experiment to gauge the therapeutic potential of M. racemosus, the researchers gave irradiated mice a cheese fermented with the fungus, and found it reduced intestinal inflammation, enhanced intestinal barrier integrity, and lowered systemic markers of inflammation, compared to mice fed cheese without the fungus.

A lot more research will need to be done before we can conclude that everybody should be eating M. racemosus as part of a balanced diet, but the researchers note that the fungus already occurs naturally in or is added to some fermented foods, and is FDA-approved for dietary use.

However, because M. racemosus may present a health threat to immunocompromised individuals, we should tread carefully in terms of figuring out how the fungus might best find a home in the food pyramid or your medicine cabinet – and maybe some of its pals too.

"More broadly, these findings establish filamentous fungi as underappreciated yet influential agents in the microbiota–host axis," the researchers write, "with potential applications for mitigating radiation-induced damage and other health conditions."

The Life of Earth

https://chuckincardinal.blogspot.com/

Scientists Accidentally Caused a Methane Leak Beneath The South China Sea. Ocean Life Sealed It Almost Instantly.

08 Sept. 2026, By C. Cassella

https://www.sciencealert.com/drilling-accidentally-created-a-methane-leak-beneath-the-south-china-sea-within-a-year-animals-helped-plug-it

A natural cold methane seep. 

(Schmidt Ocean Institute/ROV SuBastian)

In 2018, Chinese geologists created a methane leak in the South China Sea.

They were trying to figure out how much natural gas might exist in marine sediments, so they drilled a hole in the seafloor, as part of their work for the government-owned China Geological Survey.

Afterward, they tried to seal the hole with heavy mud. It measured just 22 centimeters (9 inches) wide. But their attempt failed.

A year later, a plume of methane gas had shot up from the deep, rising more than a kilometer high into the water column.

It was a mistake that scientists thought would take decades, if not a century, to naturally resolve.

Then, something incredible happened.

Using echosounders, underwater cameras, and chemical sensors, researchers watched in awe as a swarm of ocean life flocked to the hole and contained the leaking gas with "remarkable speed".

"Within just one to two years, an effective methane-consuming ecosystem had already formed," says microbial ecologist Emil Ruff of the University of Bremen in Germany.

According to past models, a fully functioning methane-munching community on the ocean floor can take between 60 and 100 years to develop.

This one was chewing through nearly as much methane in a fraction of the time.

The human-made methane leak in 2023 compared to a mature and naturally occurring cold seep for comparison. 

(Liang et al., National Science Review, 2026)



The first lifeforms to arrive on the scene were methane-munching bacteria and archaea. Overall, the diversity of microbes in the sediments took a hit, but species that consume methane thrived.

These single-celled organisms were then followed by an influx of burrowing invertebrates, which created an extensive 'worm bed' over the hole.

Crustaceans crawled to the scene as well.

"The worms, in turn, benefited from the newly established microorganisms, which likely served as a food source," explains Ruff.

"Animals and microorganisms thus contributed jointly to methane breakdown."

As tube worms burrowed into the seafloor, they helped mix the sediment, and this probably transported oxygen, nitrate, and sulfate into deeper layers, says Ruff.

Before the hole was drilled, there was no detection of gas flow and only scarce seafloor colonization in this particular spot.

With just one poke, however, everything changed. Scientists accidentally let trapped methane loose, restructuring the local ecosystem as a result.

The expansion and thickening of the worm bed from 2021 to 2023. 

(Liang et al., National Science Review, 2026)



Bubbles of methane were still leaking from the hole in 2023, but as the living filter developed, the plume's height fell from 1,200 meters (0.74 miles) above the seafloor to roughly 800 meters.

That might sound like a promising turn of events, but this research points to a larger problem.

Seafloor sediments are home to Earth's largest reservoir of methane, and natural cracks in the ocean floor allow some of that gas to seep out. This can support thriving ecosystems in the deep, dark ocean where sunlight and nutrients are scarce.

But methane is also a major greenhouse gas, accounting for about 11 percent of global emissions and trapping vastly more heat than carbon dioxide.

Acoustic imaging of the methane plume, which was still leaking as of 2023. 

(Liang et al., National Science Review, 2026)



Today, we know that abandoned oil and gas wells on the ocean floor can be a large source of methane (not to mention the massive leaks seen rising from terrestrial infrastructure and subsea pipelines).

In 2012 and 2013, for instance, scientists in Germany observed methane bubbles leaking from seabed areas around abandoned wells in the North Sea.

Later, a follow-up study found leaks at 28 out of 43 wells examined (63 percent).

"The results clearly show that thousands of tons of methane are leaking from old drill holes on the North Sea floor every year," marine geoscientist Christoph Böttner, the study's main author, said in 2020.

What isn't clear just yet is how much of that methane makes it out of the ocean and into the atmosphere.

In 2025, simluations found that methane leaks in the ocean that were deeper than 300 meters (985 feet) may not contribute much to atmospheric greenhouse gases, after all.

Most of the methane from these deeper sources dissolves in the water column, according to models.

But even if methane stays in the ocean, a surge can still lead to local troubles, including oxygen depletion, acidification, and a major restructuring of the ecosystem.

That doesn't bode well for the South China Sea, where scientists are investigating a future commercial methane-hydrate industry.

From 2010 to 2020, Chinese programs completed more than 80 drilling evaluation wells in the South China Sea.

It's unknown how many of these were successfully sealed or how they impacted the local environment.

This new study is one of the first to track a leak over several years.

It found that the wider seabed ecosystem was impacted within just a few years of human disturbance.

"Extensive sampling at more than 40 sites surrounding the discharge center revealed the occurrence of elevated methane concentrations in surface sediments even at a 500-meter distance from the discharge center," the study authors write.

"This was accompanied by a more than 30 percent reduction in microbial richness."

More research is needed, but the study authors suspect that even micromolar increases in sediment methane are linked to significantly lower microbial diversity and lower oxygen.

If methane's impact as a greenhouse gas in the atmosphere is becoming increasingly clear through super-charged weather events, its impact on deep-sea ecosystems is only just coming to light.

The Life of Earth

https://chuckincardinal.blogspot.com/

Arctic Rivers Are Defying What Scientists Thought They Knew About Erosion

07 Sept. 2026, By D. Nield

https://www.sciencealert.com/arctic-rivers-are-defying-what-scientists-thought-they-knew-about-erosion

The researchers combined lab experiments with Arctic field work. 

(Simon Fraser University)

Scientists have to follow the data, even if it doesn't make sense.

This is the situation that researchers recently found themselves in when analyzing the flow of rivers in the Canadian High Arctic.

Scientists from Simon Fraser University and the University of British Columbia in Canada were investigating river erosion.

Their starting point was the idea that frozen ground slows erosion, as the ice packed inside it was thought to act like glue, keeping the surrounding sediment locked in place.

However, field recordings have suggested something else is going on: That new river channels in the Arctic can form surprisingly quickly, suggesting erosion may actually outpace that in temperate landscapes.

A glass flume was used in the lab to stand in for Arctic rivers.

 (Simon Fraser University)



In controlled lab experiments, the researchers found that, to their surprise, this was the case.

Sediment erosion was around 10 times faster than what would be expected with unfrozen ground – findings that defied what they thought they knew about river erosion.

"We literally expected to see the opposite of what we ended up seeing," says environmental scientist Jonas Eschenfelder from Simon Fraser University.

"We re-ran the experiments a whole bunch of times until my supervisor actually believed the results."

In the lab, the team built a glass-sided 'flume' tilted at an angle, measuring 120 centimeters (47.2 inches) in length and 2 centimeters (0.8 inches) in width. Inside the channel, glass beads stood in for river gravel.

When testing frozen water over both frozen and unfrozen sediment beds, the surprising erosion results appeared. What had previously been strange anomalies in the field were being replicated over and over again.

https://www.youtube.com/watch?v=3EEM6Slr_hY

"We saw the results, we looked at ourselves, we said, 'this can't be correct'," says environmental scientist Shawn Chartrand, from Simon Fraser University.

"I emailed some colleagues. They didn't believe me. We ran a second experiment. Same outcome."

The researchers developed mathematical models to help explain what they were seeing, based on the movement of beads and water in their simulation. They also traveled to the Arctic island of Tallurutit (Devon Island) to put their models to the test.

Here's what seems to be happening: During times when the ground is fully frozen, the erosion is limited, as expected. Nothing can move.

However, as seasonal thawing begins, a shallow layer of sediment melts while frozen ground remains beneath it.

Running water can't go down through the remaining permafrost, so instead it splits off in different directions, taking more sand and soil particles with it. That explains the accelerated erosion recorded in this study.

"You think you understand the basics of how things work, but it doesn't work that way sometimes," says Chartrand.

This is vital knowledge to have as researchers try to understand and predict what's going to happen to the Arctic region as climate change continues, and as more ice disappears from a landscape that's been frozen for thousands of years.

In the researchers' words, the Arctic is "waking up" as temperatures rise, and that awakening includes the appearance of more river systems.

Potential next steps include more detailed field recordings in the Arctic, spread across the entirety of the year and under different temperature conditions, to confirm the accelerated erosion process that's happening.

"The Arctic is becoming an increasingly important place, in terms of geopolitics, environmental concerns and infrastructure projects," says Eschenfelder. "But we clearly don't really know how it is behaving with climate change.

"Our science tries to bridge that gap so we can project future conditions and answer questions about how the landscape is evolving."

The Life of Earth

https://chuckincardinal.blogspot.com/

Ancient Human Teeth Uncover a Genetic Connection Hidden for 400,000 Years

By Chinese Academy of Sci. Sept. 6, 2026

https://scitechdaily.com/ancient-human-teeth-uncover-a-genetic-connection-hidden-for-400000-years/

A cartoon illustration of the AMBN enamel protein. 

Credit: IVPP

Enamel proteins from Homo erectus teeth suggest genetic links to Denisovans while offering a less destructive way to study ancient human fossils.

A handful of ancient teeth may preserve clues to a relationship that has remained difficult to trace through fossils alone.

Researchers from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences have recovered molecular evidence suggesting a possible connection between Homo erectus and modern humans, while developing less invasive paleoproteomics methods for studying rare fossils.

Homo erectus, or H. erectus, was the first species in the genus Homo known to have migrated out of Africa and occupies an important place in human evolutionary history. Yet the scarcity of molecular evidence has left major questions unresolved, including the species’ genetic characteristics, population diversity, and possible relationships with modern humans. Its role in human evolution therefore remains a major subject of debate.

One reason for this uncertainty is that ancient hominin fossils are both irreplaceable scientific specimens and valuable cultural heritage. Molecular techniques that require destructive sampling are often unacceptable, severely limiting what researchers can learn from H. erectus remains.

Proteins bypass a major fossil barrier

To work around that problem, a multi-institutional team led by Qiaomei Fu of IVPP used a micro-destructive acid etching technique to recover molecular information from six Homo erectus teeth while preserving their overall morphology.

The findings were published in Nature.

A commentary published alongside the research in Nature emphasized how enamel proteins recovered from the six Chinese H. erectus teeth provided “new insights into how ancient genetic material was eventually introduced into modern human populations.”

Two mutations connect ancient human lineages

The researchers detected two mutations in teeth from fossils at least 400,000 years old, recovered from three sites: Zhoukoudian (Peking Man), Hexian, and Sunjiadong. The variants point to possible genetic connections between East Asian H. erectus and Denisovans, an archaic human group that also contributed genetic material to modern populations.

One mutation, AMBN-A253G, had not previously been identified. The researchers propose it as a potential molecular marker for these H. erectus populations, providing the first evidence that specimens from all three sites belonged to the same evolutionary population.

The second variant, AMBN-M273V, had previously been considered specific to Denisovans. The new results indicate that it was not unique to Denisovans and was also present in these H. erectus populations.

According to the researchers, AMBN-M273V may have entered the Denisovan lineage through admixture and later reached some modern human populations (in Southeast Asia and Oceania) through Denisovan introgression. The finding offers the first molecular clues to a possible relationship between East Asian H. erectus (such as those from Zhoukoudian) and Denisovans, as well as potentially deeper genetic connections with some present-day humans.

New methods could preserve more fossils

The work also introduces a set of experimental and computational methods for future paleoproteomics research.

These include a technique for determining the sex of ancient hominins using the male-specific enamel protein AMELY, a cross-validation strategy combining tandem mass spectrometry with multiple data analysis pipelines, and DNA analysis approaches tied to specific amino acid variants. Together, the methods provide a framework for extracting molecular information from ancient fossils while reducing damage to valuable specimens.

The birth of modern Man

https://chuckincardinal.blogspot.com/