Health

Youth violence prevention program shown to reduce arrests by up to 75%

Lisa Marshall — Tue, 12 Aug 2025 16:10:25 +0000

Youth violence prevention program shown to reduce arrests by up to 75% Lisa Marshall Tue, 08/12/2025 - 10:10

Lisa Marshall

A ̽��Ƶ-led initiative to reduce youth violence in hard-hit Denver neighborhoods was associated with a 75% decline in arrests for murder, assault, robbery and other youth crimes in recent years, new research shows.

“We now have concrete data to show that when communities come together and mobilize, we can prevent youth violence, even in urban settings with a very high burden,” said senior author Beverly Kingston, director of CU’s Center for the Study and Prevention of Violence (CSPV).

The study, published in the American Journal of Criminal Justice, assesses the efficacy of the Youth Violence Prevention Center - Denver (YVPC-Denver), one of five university-community partnerships established by the Centers for Disease Control after the 1999 Columbine High School shooting.

Documentary filmmaker Antoinette "Ajay" June films Game Changer Janaya Frilot in Denver.

The centers have remained one of the only long-term federally funded efforts to address what the agency has termed the “serious public health issue” of youth violence.

Homicide is the third leading cause of death for youth ages 10 to 24 and the leading cause of death among Black youth, according to the CDC.

Now, proposed cuts to the CDC budget threaten to shutter the Denver center, housed at the CSPV, as early as next month.

“Thanks to this funding, we have been able to bring violence down in Denver while a lot of communities around the country have not,” said Dave Bechhoefer, project director for the YVPC-Denver. “To have it go away just when it is starting to get traction could have a huge impact.”

A ‘violence prevention infrastructure’

In 2011, YVPC-Denver began working with community organizations in Montbello and Park Hill to get at the root cause of youth violence plaguing the neighborhoods and come up with and implement solutions. They used a framework called Communities That Care, which hinges on two things: science-backed interventions and community involvement.

“It’s all about building a violence prevention infrastructure,” said Kingston. “Just like we have roads and bridges that we put money toward, we need to build an infrastructure that supports violence prevention throughout the life-course.”

Partner coordinator Troy Grimes, left, helps Game Changer Quavon Mosley with his new, donated tuxedo before a documentary screening.

In partnership with elementary schools, after-school programs, and faith and sports organizations, the program provided more than 3,000 youth ages 6 to 18 with training on how to handle anger and peacefully resolve conflict.

The initiative also worked with pediatricians to develop screenings for kids and get them help if they seemed at high risk of committing violence and provided mini grants to local groups matching positive adult role models with teens.

Perhaps the most visible outgrowth of the program has been the Power of One campaign, a sweeping youth-led effort in which dozens of youth, known as the Game Changers, use social media, podcasts, neighborhood block parties and more to send a message that violence is not normal.

One group of Game Changers, known as VIBEE (Violence Intervention Building Education and Empowerment) produced a film “Breaking the Cycle: Stories of Strength and Survival of Gun Violence,” which will screen in Denver this week and at ̽��Ƶ this fall.

Others recently rolled out an app that connects youth with peers for help handling food insecurity, mental health issues or gang violence.

“Sometimes the people who are causing the violence are just youth having trouble at home and having a hard time getting the help they need,” said Game Changer Annecya Lawson, who joined the program after a friend was fatally shot her sophomore year in high school. “When these kids see somebody their age, who looks like them, doing stuff for the community, it can have a big impact. They’re more likely to think before they act.”

Crunching the numbers

For the study, ̽��Ƶ researchers analyzed arrest data from the Denver Police Department for the five years prior (2012–16) and five years after (2017–21) Communities that Care was implemented in Park Hill.

They found that arrests fell 75%—from 1,086 per 100,000 people in 2016 to 276 per 100,000 in 2021.

The Game Changers stand with community members at the Expressions of Hope Art Therapy event in Denver in April.

The authors acknowledge that other pandemic-related factors, gentrification or violence prevention efforts could have contributed some to the declines. But rigorous statistical analysis suggests that program is "the most plausible explanation for the sharp decrease."

On average, across 74 Denver neighborhoods, youth arrests fell 18% between 2016 and 2021.

Montbello, which had implemented Communities that Care several years before Park Hill, had already established lower violence rates and maintained them throughout the study period even as they climbed sharply elsewhere amid the COVID-19 pandemic.

This suggests the violence prevention infrastructure had lasting impacts.

“In the 15 years we have been working in these communities we have seen many times, anecdotally, what can happen when communities come together to prevent violence. But to be able to have the data behind it now is incredibly exciting,” said Kingston.

Kingston recently got word that the final year of funding for the center's current five-year grant cycle is at significant risk of being revoked. Loss of the $1.2 million would jeopardize the existence of the Game Changers and make it impossible for the YVPC – Denver to continue.

“Losing this funding would be devastating,” said Kingston. “Not just for Denver but for communities nationwide looking to replicate this success.”

A ̽��Ƶ-led effort to help high-risk communities build a “violence prevention infrastructure” contributed to sharp declines in arrests for murder, assault and other youth crimes in Denver, new research shows. The program is now poised to lose its federal funding.

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The Game Changers, a group of young people working to curb youth violence in Denver, pose for a photo. Credit: Miss Money Shot Productions

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The Game Changers, a group of young people working to curb youth violence in Denver, pose for a photo. Credits: Miss Money Shot Productions

Study: Using cannabis and psilocybin together may increase dependence

Megan Maneval — Mon, 11 Aug 2025 19:00:07 +0000

Study: Using cannabis and psilocybin together may increase dependence Megan Maneval Mon, 08/11/2025 - 13:00

Colorado Arts and Sciences Magazine

̽��Ƶ researchers studied cannabis-psilocybin users and cannabis-only users to look for similarities and differences between the two groups, including drug use motivations.

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Medical issues and neighborhood opportunity can affect infant development

Megan Maneval — Thu, 07 Aug 2025 14:57:23 +0000

Medical issues and neighborhood opportunity can affect infant development Megan Maneval Thu, 08/07/2025 - 08:57

Colorado Arts and Sciences Magazine

̽��Ƶ researcher Emily Yeo finds that some babies may benefit from more support and resources so they can grow up to lead long, happy and healthy lives.

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Black Death offers clues into how childhood malnutrition shapes adult health

Daniel William Strain — Wed, 30 Jul 2025 17:33:52 +0000

Black Death offers clues into how childhood malnutrition shapes adult health Daniel William… Wed, 07/30/2025 - 11:33

Daniel Strain

The Black Death arrived on the shores of England in May 1348 and, in less than two years, spread throughout the country, killing an estimated 2 million people. The death toll from the disease, which was caused by the bacterium Yersinia pestis, got so high that officials in London and other cities opened new cemeteries where hundreds of bodies were interred every day.

According to a new study, those who died around the time of the Black Death may help scientists answer a decidedly modern question: How can malnutrition early in life shape the health of humans far into adulthood?

Illustration in the medieval manuscript Tractatus quartus bu Gilles li Muisit depicting people burying victims of the Black Death. (Credit: Public domain image via Wikimedia Commons)

The answer may be more complicated than scientists once suspected, said Sharon DeWitte, lead author of the study and a professor in the Institute of Behavioral Science and Department of Anthropology at the University of Colorado Boulder.

In the new research, DeWitte and her colleagues examined chemical clues hidden in the teeth of nearly 275 people buried in English cemeteries before, during and after the Black Death. The team discovered something surprising: People who experienced malnutrition early in their lives may have survived threats to their health, like plague, at greater rates than their peers up until young adulthood, or roughly before the age of 30.

Those survival advantages, however, could have dropped significantly when the same individuals entered their middle and late adult years.

“What this might indicate is that if people experienced a period of starvation early in their childhoods or adolescence but survived, that could have shaped their development in ways that were beneficial in the short term but led to poor outcomes once they got older,” DeWitte said.

She and her colleagues published their findings July 30 in the journal Science Advances.

The research is part of DeWitte’s ongoing effort to understand the past to help humans living today.

“Mortality varied during a catastrophe 700 years ago in ways that might have been preventable,” she said. “My hope is that we can absorb that lesson and think about how human health can vary across different social categories today, and figure out the points of intervention where we can do something to reduce that burden.”

Childhood health

How experiences early in life shape our health long into the future is far from clear cut.

Some studies of modern humans, for example, have linked low birth weights in infants to health problems later in life. Babies born small, a possible sign of nutritional stress, seem to be more prone to illnesses like cardiovascular disease and diabetes in adulthood than the population at large.

The remnants of Thornton Abbey in Lincolnshire, United Kingdom, the site of a cemetery where victims of the Black Death were buried en masse. (Credit: CC photo by David Wright via Wikimedia Commons)

Sharon DeWitte

The Black Death, sometimes known as the second pandemic of plague, might be an ideal laboratory for studying these questions, DeWitte noted. In part, that’s because the death toll around Europe varied drastically—in some parts of England, for example, about 30% of the population died, while mortality rates reached 75% in Florence, Italy.

“It raises questions about why mortality was higher in some populations than others,” she said.

To pursue those questions, DeWitte and her colleagues turned to teeth.

Environment matters

She explained that what humans eat as infants and children leaves a mark in the development of our adult teeth—subtly shifting the types, or “isotopes,” of carbon and nitrogen atoms present in the dentine. In particular, when people experience extreme nutritional stress, their bodies will begin to break down their own fat stores and muscle, which have a different signature of isotopes than food that is eaten.

In the current study, DeWitte’s team examined the isotopes present in the teeth of hundreds of people buried in English cemeteries between 1100 to 1540 AD. They included the East Smithfield Black Death Cemetery, which opened in London in 1348 and where the bodies of hundreds of plague victims were stacked in a mass burial trenches.

DeWitte emphasizes that the team’s results are far from definitive—in many cases, the researchers don’t have any records about the humans they studied, so it’s hard to know for sure how they died or how healthy they were in life.

But the findings carry hints that malnutrition early in life may shape the health of adults in ways that aren’t necessarily good or bad—it all depends on context.

When infants or children don’t have enough to eat, DeWitte said, their bodies may develop in ways that prime them for hardship later in life. They may have altered metabolism, for example, so that they use calories, which may be scarce, more efficiently.

Those changes can be beneficial—that is, until the environment changes and food becomes more plentiful. Some evidence, for example, suggests that in the wake of the Black Death, conditions for survivors in England improved as laborers demanded higher wages.

“People who experienced nutritional stress as children may have had a mismatch with their environments later in life,” DeWitte said. “If there’s now a resource abundance, but their bodies were shaped for an environment of scarcity, they may have poor health outcomes, like packing too many fat stores, which can lead to cardiovascular disease.”

For DeWitte, the study is another example of what humans living today can learn from people who died hundreds of years ago:

“For a very long time, I've been interested in this question of why some people experience good health and others living in the exact same society don’t.”

Co-authors of the new research include Julia Beaumont and Jacqueline Towers at the University of Bradford in the United Kingdom; Brittany Walter of the Defense POW/MIA Accounting Agency; and Emily Brennan at the University of South Carolina.

Experiencing malnutrition in childhood or adolescence may not necessarily harm the health of humans into adulthood—although the relationship is complicated, a new study finds.

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Yersinia pestis bacteria seen through fluorescent imagine. (Credit: CDC)

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The Black Death was caused by Yersinia pestis bacteria, seen here through fluorescent imaging, and largely spread through fleas. (Credit: CDC)

In microbial wars, bacteria suit up with a protein linked to Alzheimer’s

Yvaine Ye — Tue, 29 Jul 2025 16:30:39 +0000

In microbial wars, bacteria suit up with a protein linked to Alzheimer’s Yvaine Ye Tue, 07/29/2025 - 10:30

Lisa Marshall

Amyloids are perhaps best known as a key driver of Alzheimer’s disease.

The amorphous proteins, found throughout the human body, stick to nerve cells like plaque, choking off their function and contributing to a host of neurodegenerative diseases.

According to new University of Colorado Boulder research published this month in the journal Nature, these oft-maligned proteins also serve a critical role for bacteria in our environment, enabling them to fight off other “predatory bacteria.”

“We discovered that bacteria all around us are using amyloids as a molecular suit of armor,” said senior author Aaron Whiteley, assistant professor in the Department of Biochemistry.

By better understanding how bacteria defend themselves against threats, scientists could ultimately develop new tools to kill microbes growing out of control in places like hospitals and food processing facilities, he said. Such research can also offer new insight into how the human immune system works.

“A lot of the cellular machinery that makes up our own immune system actually originated in bacteria a billion-plus years ago,” said Whiteley. “If we can understand how bacteria are using those genes, we can better understand how humans use them too and possibly turn that knowledge into new therapies.”

E. Coli bacteria in green and their molecular suit of armor made of amyloid in purple. (Credit: Aaron Whiteley)

War between bugs

In recent years, the scientific community has grown increasingly interested in how bacteria fight off viruses, or phages. Such research led to the Nobel Prize -winning gene splicer, CRISPR.

Less attention has been paid to how bacteria fight off their own “predatory bacteria.”

For the new study, Whiteley and postdoctoral fellow Hannah Ledvina zeroed in on one particularly ruthless predatory bacterium called Bdellovibrio bacteriovorus. Beter known as “Bdello” (pronounced Dell-O), the microbial cannibal worms its way inside of other bacterial species, leaching out their nutrients until they starve to death— and then swims off to destroy again.

Bdello are everywhere from your shower to your neighborhood creek to your mouth.

“They are generally harmless to humans, but they are deadly to the bacteria that make us sick,” said Whiteley. “Even E. coli has to worry about catching one of these predatory bacteria.”

Conventional wisdom has held that Bdello are, essentially, invincible, with other bacteria fairly powerless to fight them off. (This has made Bdello a favorite candidate for emerging efforts to fight problem bacteria with bacteria.)

But Whiteley wondered: Do some bacteria put up a fight against such predatory bacteria and win?

And if so, how?

Armor made of amyloid

To find out, the research team started by amassing a vast collection of exotic E. coli strains from various sources around the globe, including the guts of a lizard, the urinary tract of a patient in Sweden and scat samples from leopards and kangaroos.

Then they set Bdello loose on these bacteria.

“We were blown away,” said Whiteley. “We found that about one-third of the strains were actually resistant to Bdello.”

In subsequent tests using a high-tech microscope, the team could see just how those resistant strains fought back.

The images showed clearly that the resistant strains completely coated themselves in a type of amyloid protein called curli, which is similar but not identical to the amyloids that cause Alzheimer’s disease.

In follow-up studies using genetic sequencing, the team found that bacteria used curli to fight back against other predatory bacteria, too.

“We contend that the same characteristics that make amyloids a problem for humans — the fact that they are durable and hard to break down—make them an ideal suit of armor for bacteria, which they use to defend against a wide range of threats,” said Whiteley.

Know thy enemy

The study also suggests that bacteria enlist amyloids to develop biofilms—the thin layers of resistant bacteria that persist on hospital instruments, medical implants, industrial machines and other surfaces, breeding infection and corroding parts.

Today, a common way to get rid of a biofilm is to scrape it off.

But Whiteley suspects that Bdello and other strains of predatory bacteria may have developed genetic tools or unique enzymes able to disintegrate that rigid shield and break down biofilm.

“Wherever organisms are fighting, there is biochemical innovation happening,” he said.

He and his colleagues are now working to determine what those shield-busting tools may be, in hopes that they bould be co-opted to develop new ways of fighting antibiotic resistance or amyloid-fueled diseases like Alzheimer’s.

As the bacteria in our environment duel it out, he’ll be watching.

“If we can understand what makes this armor so durable and what some predatory bacteria are doing to circumvent it, it could have all sorts of implications for human health,” he said.

New research shows that bacteria in the environment use amyloids— proteins best known for contributing to neurodegenerative disease— to shield themselves from predators. The findings could inform new weapons against microbial resistance and human disease.

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Escherichia Coli (E. Coli) bacteria under the microscope. (Credit: Adobe Stock)

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Escherichia Coli (E. Coli) bacteria under the microscope. (Credit: Adobe Stock)

What rats can tell us about the opioid crisis

Megan Maneval — Wed, 23 Jul 2025 18:48:47 +0000

What rats can tell us about the opioid crisis Megan Maneval Wed, 07/23/2025 - 12:48

Colorado Arts and Sciences Magazine

In a recent study, ̽��Ƶ scientists have estimated the heritability of opioid use disorder—an ongoing global health crisis.

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New cancer therapy clings to tumors, with inspiration from gecko toes

Lisa Marshall — Mon, 21 Jul 2025 19:59:44 +0000

New cancer therapy clings to tumors, with inspiration from gecko toes Lisa Marshall Mon, 07/21/2025 - 13:59

Lisa Marshall

For millennia, the gecko has offered inspiration to humans.

As far back as the 4th Century B.C., Aristotle marveled at the nimble reptile’s ability to “run up and down a tree in any way, even with the head downwards.”

Its grippy toes, able to latch on to even the slipperiest surface with extraordinary force, have inspired everything from super glues to “Superman” climbing suits to sponges for soaking up environmental toxins.

Now ̽��Ƶ scientists have taken a cue from the remarkable reptile to develop a material able to stick to tumors inside the body, pumping out chemotherapy drugs for days.

The technology, developed with doctors at the University of Colorado Anschutz Medical Campus, is described in the journal Advanced Materials.

“Nature has been at this for millions of years and offers clues for developing better biomaterials,” said senior author Wyatt Shields, Thomas F. Austin assistant professor of Chemical and Biological Engineering at ̽��Ƶ.

First-author Jin Gyun Lee, a postdoctoral researcher in the Shields Lab, said early results show great promise.

“We envision that this gecko-inspired technology could ultimately reduce the frequency of clinical treatments, potentially allowing patients to receive fewer but longer-lasting therapies,” Lee said.

Millions of hair-like fibers, called setae, on the bottom of gecko toes enable them to stick to slippery surfaces. Credit: Adobe Stock Photo

The power of sticky toes

How does a gecko manage to effortlessly ascend a glass wall or glide across a slippery ceiling?

The secret lies in the millions of microscopic, hair-like fibers, called setae, that line their toes.

With each step, these hair-like structures — and thousands of even tinier split ends called spatulae — flatten out across a broad surface area, conforming into nooks and crannies.

When molecules on the spatulae and surfaces interact— through a phenomenon known as Van der Waals forces— their feet stick, and stick hard.

Yet just a slight movement can break the bond, enabling them to scurry on.

Scientists have tried for decades to replicate the miracle that is the gecko toe, for use in stronger adhesives, medical and personal care products, and more.

But those tiny hairs have proven complicated and expensive to fabricate and almost impossible to make at scale.

Shields, whose lab develops materials for medical applications, faced an additional challenge: He and Lee sought to invent a material that could linger safely in the body, delivering a sustained dose of medicine, before disintegrating.

They developed a way to turn an already FDA-approved biodegradable polymer, poly lactic-co-glycolic acid (PLGA), into small particles displaying branched hair-like nanostructures similar to those on the gecko’s feet.

They loaded these “soft dendritic particles” with chemotherapy drugs and attached them to cancer cells in a petri dish and bladder tumors in mice.

The study showed that the particles clung tightly to the cancer for days, even in a slippery environment like the surface of a bladder. The animals tolerated them well and the treatment elicited a favorable immune response. And the particles were also cheap and easy to make, said Lee:

“We’ve developed a practical, flexible platform for localized cancer therapy that could be easily scaled and translated.”

The challenge with bladder cancer

The authors stress that more research is necessary, and it could be years before the technology is ready for clinical trials in people.

Ultimately, they say, it could be a game changer for treating localized tumors (those still confined to one spot), with minimal damage to healthy surrounding tissue.

The team started with bladder cancer, which is diagnosed in about 85,000 people and kills 18,000 people annually, because it can be uniquely challenging to treat.

New gecko-inspired 'soft dendritic particles' (SDPs) could be loaded with chemotherapy drugs and stuck to the surface of bladder tumors for sustained, targeted treatment.

“Bladder cancer is common, with most patients presenting with localized disease,” said co-author Thomas Flaig, MD, an oncologist and professor of medicine at CU Anschutz who specializes in bladder cancer. “There is a real need for new and effective therapies to prevent progression to more advanced disease for these patients.”

To treat localized bladder tumors, doctors typically insert a catheter into the bladder and bathe the whole organ in chemotherapy drugs. Because people urinate about six times a day, the medication washes out fast, necessitating frequent repeat treatments that can be painful. Side effects are common, since the drugs hit the healthy tissue, too. Often, the cancer comes back.

The researchers envision a day when a gel containing their gecko-inspired particles could be applied directly to the tumor, selectively delivering a sustained, high concentration of cancer-killing medicine until it breaks down and is excreted.

The technology could also work for other cancers, such as oral, head or neck tumors.

The team of biomedical and materials engineers, medical oncologists and cancer biologists plan to continue their cross-campus collaboration — and look to nature for inspiration.

“These are early days in this work, but this is a really promising start,” said Flaig, also vice chancellor for research for the Anschutz Medical Campus. “Often the scientific projects that bring together those with distinct areas of expertise have the best chance to have the biggest impact.”

The tiny lizards can climb glass and cling to ceilings thanks to their sticky toes. Now those toes have inspired a new material that could deliver targeted chemotherapy with minimal side effects.

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The nimble gecko, able to cling to glass and other slippery surfaces, has inspired scientists for centuries.

Common sugar substitute shown to impair brain cells, boost stroke risk

Lisa Marshall — Mon, 14 Jul 2025 16:45:17 +0000

Common sugar substitute shown to impair brain cells, boost stroke risk Lisa Marshall Mon, 07/14/2025 - 10:45

Lisa Marshall

From low-carb ice cream to keto protein bars to “sugar-free” soda, the decades-old sweetener erythritol is everywhere.

But new ̽��Ƶ research shows the popular sugar substitute and specialty food additive comes with serious downsides, impacting brain cells in numerous ways that can boost risk of stroke.

The study was published in the Journal of Applied Physiology.

“Our study adds to the evidence suggesting that non-nutritive sweeteners that have generally been purported to be safe, may not come without negative health consequences,” said senior author Christopher DeSouza, professor of integrative physiology and director of the Integrative Vascular Biology Lab.

First approved by the Food and Drug Administration in 2001, erythritol is a sugar alcohol, often produced by fermenting corn, and found in hundreds of products made by various brands. It has almost no calories, is about 80% as sweet as table sugar, and has negligible impact on insulin levels, making it a favorite for people trying to lose weight, keep their blood sugar in check or avoid carbohydrates.

But recent research has begun to shed light on its risks.

One recent Cleveland Clinc study involving 4,000 people in the U.S. and Europe found that men and women with higher circulating levels of erythritol were significantly more likely to have a heart attack or stroke within the next three years.

DeSouza and first author Auburn Berry, a graduate student in his lab, set out to understand what might be driving that increased risk.

To test impacts of erythritol on cells, researchers in the lab treated human cells that line blood vessels in the brain for three hours with about the same amount of erythritol contained in a typical sugar-free beverage.

They observed that the treated cells were altered in numerous ways:

They expressed significantly less nitric oxide, a molecule that relaxes and widens blood vessels, and more endothelin-1, a protein that constricts blood vessels. Meanwhile, when challenged with a clot-forming compound called thrombin, cellular production of the natural clot-busting compound t-PA was “markedly blunted.” The erythritol-treated cells also produced more reactive oxygen species (ROS), a.k.a. “free radicals,” metabolic byproducts which can age and damage cells and inflame tissue.

Previous research has shown that as little as 30g of erythritol—about as much as you’d find in a pint of sugar-free ice cream—can also cause platelets, a component of blood, to clump together, potentially forming clots.

“Big picture, if your vessels are more constricted and your ability to break down blood clots is lowered, your risk of stroke goes up,” said Berry. “Our research demonstrates not only that, but how erythritol has the potential to increase stroke risk.”

DeSouza notes that their study used only a serving-size worth of the sugar substitute. For those who consume multiple servings per day, the impact, presumably, could be worse.

The authors caution that their study was a laboratory study, conducted on cells, and larger studies in people are now needed.

That said, De Souza encourages consumers to read labels, looking for erythritol or “sugar alcohol” on the label.

“Given the epidemiological study that inspired our work, and now our cellular findings, we believe it would be prudent for people to monitor their consumption of non-nutrient-sweeteners such as this one,” he said.

New research shows that the popular sweetener erythritol, often recommended for people with obesity and diabetes, comes with health risks of its own.

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Can weed labels be trusted? Study shows it depends on what you're buying

Lisa Marshall — Thu, 03 Jul 2025 14:24:08 +0000

Can weed labels be trusted? Study shows it depends on what you're buying Lisa Marshall Thu, 07/03/2025 - 08:24

Lisa Marshall

Nearly half of cannabis flower products are inaccurately labeled when it comes to potency, with most showing they contain more THC than they really do. Meanwhile, labels on cannabis concentrates like oils and waxes tend to be accurate, with 96% shown to match what’s inside.

That’s the takeaway from a sweeping new analysis of products sold at dispensaries across Colorado—the first state to legalize recreational marijuana.

The study, published this month in the journal Scientific Reports, is the first comprehensive label audit of legal market cannabis to date, providing insight into just how strong cannabis has become, what the burgeoning industry is getting right in terms of testing and labeling and where it can improve.

“Cannabis use has complex and wide-ranging effects, and we are working hard to better understand them,” said senior author Cinnamon Bidwell, associate professor of psychology and neuroscience and co-director of the Center for Health and Neuroscience, Genes and Environment (CU Change). “While that research plays out, we should, at the very least, be providing accurate information about the amount of THC in these products.”

The study was funded by the Institute of Cannabis Research, the state’s official cannabis research institute, and conducted in collaboration with MedPharm Research, LLC, a cannabis manufacturer and cultivator that holds state and federal licenses to conduct cannabis research.

“We want to instill and foster trust in products, and the only way to do that is to continually evaluate and correct any issues that might be discovered,” said Duncan Mackie, director of pharmacology at MedPharm and a co-author on the paper.

Stronger cannabis, problematic labels

Under federal law, university scientists are not allowed to purchase or handle legal market cannabis for research, so collaborating with industry is critical, said first author Gregory Giordano, professional research assistant in the Department of Psychology and Neuroscience.

For the study, a secret shopper from MedPharm traveled the state to obtain 277 products from 52 dispensaries across 19 counties.

A sampling of cannabis products purchased at Colorado dispensaries, including: three kinds of loose flower (a, b, c); a pre-rolled joint (d); shatter (e); Moroccan Hash (f); sugar (g); distillate concentrate (h).

The sampling included 178 flower products (loose flower and pre-rolled joints) and 99 smokable concentrates—everything from vials of distilled liquids to balls of Moroccan hash and gobs of waxy “sugar.” No edibles were included in this phase of the study.

The shopper shared label photos with Bidwell’s team. Then the samples, marked only with a number, were tested by MedPharm chemists who hadn’t seen the labels.

Data analysis showed that flower products contained on average about 21% THC, or tetrahydrocannabinol—the main psychoactive ingredient in cannabis. Concentrates contained 71% THC on average, with some containing as much as 84%.

In the 1980s, the typical THC content in marijuana was around 8%.

“THC content has increased significantly, and we know that greater THC exposure is likely associated with greater risks, including risk of cannabis use disorder and some mental health issues,” notes Bidwell.

Products were considered “accurately labeled” if they contained within 15% of the THC amount shown on the label—the same threshold the state uses. ̽��Ƶ 44% percent of flower products failed to meet that standard, with 54 of those products inflating their THC content on the label and 23 containing more THC than the label indicated.

Either is concerning, the researchers say.

For those using cannabis medically, adequate dosing can be critical. For those using cannabis recreationally, taking more than expected can be dangerous.

Some discrepancies were large — one flower product was labeled as having 24% THC but had only 16%. But on average, the difference between labeled and observed THC was about 2%.

Only four concentrate products were labeled inaccurately.

“When it comes to concentrates, I would say Colorado gets a good grade for labeling accuracy, but there are some real issues with flower,” said Bidwell.

Previous research in other states has shown that third-party testing labs often inflate THC potency, possibly to gain the business of marketers wanting to attract consumers seeking stronger products.

However, there are other potential explanations for the discrepancy: Concentrates are often made from homogenous oils that are easier to analyze, whereas plants are inherently heterogenous and harder to test.

Small changes in testing protocols could reduce mislabeling, the researchers said.

Beyond THC and CBD

The study also looked at several other cannabinoids (active compounds found in the Cannabis sativa plant), including cannabidiol (CBD), cannabigerol (CBG), and cannabigerolic acid (CBGA). Colorado law requires that companies put CBD levels on the label, a standard that 80% to 85% of products met.

But only 16% of products featured any information at all about other lesser-known cannabinoids.

Notably, CBG and CBGA, which have been associated with anti-inflammatory and anti-anxiety properties, was more abundant than CBD in products across categories.

“Focusing on THC on the label can actually do a disservice for consumers, because it creates an environment in which people buy based solely on THC content,” said Bidwell. “Our data suggests that multiple other cannabinoids should also be reported on there.”

What’s next? With support from the Institute of Cannabis Research, Bidwell and Mackie plan to look at, among other things, labels for cannabis edibles.

As more states legalize the plant for medicinal and recreational uses, they hope their research can inform how states regulate it.

“We all want the same thing,” said Mackie, “a strong, successful industry that regulators can feel good about, businesses can thrive in, and customers can trust.”

A sweeping new analysis of cannabis products shows that while high-potency concentrates like oils and waxes tend to be labeled accurately, flower products often overstate their THC content. The study also found that cannabis potency has increased exponentially.

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Loose flower cannabis in jars at a retail store. Credit: Adobe Stock

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Loose flower cannabis in jars at a retail store. A new study shows that when it comes to potency, labels are often inaccurate. Credit: Adobe Stock Photos

Faith Kipyegon could become the first woman to run a sub-4-minute mile this week. Here’s how, and why it matters

Lisa Marshall — Wed, 25 Jun 2025 05:50:07 +0000

Faith Kipyegon could become the first woman to run a sub-4-minute mile this week. Here’s how, and why it matters Lisa Marshall Tue, 06/24/2025 - 23:50

Lisa Marshall

Clad in featherlight spikes, a custom 3D-printed sports bra and an aerodynamic speed suit, Kenyan Olympian Faith Kipyegon will step onto a Paris track this week and try to become the first woman to run a sub-4-minute mile.

The attempt comes four months after ̽��Ƶ researchers published a paper suggesting she could do it, particularly if Kipyegon used strategically timed and placed pacers to block the wind coming at her.

They ended their paper with the words: “Hopefully Ms. Kipyegon can test our prediction on the track.”

This Thursday, they’ll be watching intently.

“I've been making hypotheses since about 1984, and none of them have been anywhere near this publicly tested,” said study author Rodger Kram, an associate professor emeritus in the Department of Integrative Physiology and an expert in running physiology and biomechanics. “It's a little bit scary, but it's also super exciting.”

The “Breaking4” event, hosted by Nike, resembles the 2017 Breaking2 Project, in which Nike set out to create the perfect conditions for Kenyan Eliud Kipchoge to break the two-hour marathon barrier. (He missed it but nailed it in a similar event in 2019).

Reportedly, Nike first started planning Breaking4 some 18 months ago.

Like Breaking2, Breaking4 has been informed by ̽��Ƶ research.

“Our study found that if everything went right, under a couple of different drafting scenarios, Faith Kipyegon could break the 4-minute barrier,” said co-author Shalaya Kipp, an Olympic middle-distance runner who earned her master’s degree in Kram’s lab. “It’s extremely exciting that we are now talking about, and studying, the limits of female human performance, too.”

The Mount Everest of running

When Roger Bannister ran the first sub-4-minute-mile on May 6, 1954, it made international news and inspired a new generation of male runners.

“It was the running equivalent to summiting Mount Everest for the first time,” said Kram. “Before that, it was considered beyond the limits of human physiology.”

But progress in women’s running was slower to come.

When Diane Leather became the first woman to run a sub-5-minute-mile just 23 days after Bannister’s race, it received little attention.

From 1928 to 1960, women were prohibited from running anything longer than 200 meters in the Olympics, due to unfounded concerns that it could harm their reproductive health. And women weren’t permitted to run the Boston Marathon until 1972.

We’ve come a long way, the researchers say, with women now outnumbering men in U.S. running races as a whole. But women still participate less in middle- and long-distance running than men do globally.

“The 4-minute-mile was an elusive barrier for humankind, and now if we actually had a woman do it, it would give a whole new generation of track athletes something to go after,” said Kipp.

The power of drafting

Not all are convinced Kipyegon will succeed.

Some have publicly expressed their doubts that the 31-year-old mother can carve 7.64 seconds off her already lightning-fast mile record set in Monaco in 2023.

“She’s not going to break four and it’s not going to be particularly close,” wrote one skeptic.

But Kram contends that while others focus on how much energy she must expend, his team’s research emphasizes how much energy she can save by drafting—or using other runners to push the air molecules out of the way, reducing resistance.

First author Edson Soares da Silva, who traveled from the Universidade Federal do Rio Grande do Sul in Brazil to work in Kram’s lab, notes that migratory birds often fly in formation, using drafting for energy-efficient locomotion. Humans can learn something from them.

“Anyone from top elite to lower-level runners can benefit from drafting,” he said. “But, the faster the speed, the more air resistance a runner faces, and the more drafting matters.”

In the case of Kipyegon running a 4-minute-mile pace alone, just pushing against the air eats up 13% of her energy, according to the team’s calculations.

The study forecasts that if she used just two female pacers, which switch out at the half-mile point, Kipyegon could reduce that drag by about 76%, enabling her to run a 3:59:37.

A promotional video from Nike suggests that a pack of both male and female elite runners will pace Kipyegon Thursday, with some of the male runners sticking with her the entire mile—which could reduce air resistance even more, Kram said. (He notes that Bannister also used pacers for his historic run).

“On Thursday, she will have better than 70% drafting and all of these other contributing factors like the shoes and the clothing,” he said. “I think there is a really good chance that she will break four minutes.”

Watching history in the making

He’ll spend Thursday on Zoom with Kipp and co-author Wouter Hoogkamer, watching the attempt together.

Meanwhile, da Silva, now a doctoral student in France, will be in the stadium in Paris cheering her on.

“Since I live just three hours away, I feel like I am in the right place at the right time to witness the testing of our hypothesis and to see history in the making,” he said.

What if she doesn’t make it?

“As we have seen over the years in running and in other fields, one sure-fire way to motivate a woman to do something is for people to tell her she cannot do it,” said Kram. “It’s only a matter of time.”

The Breaking2 Event will be streamed live on Prime Video and Nike’s YouTube channel beginning at 1:15 PM ET Thursday, subject to weather conditions.

̽��Ƶ research suggests its possible for the Kenyan Olympian to shave about 8 seconds off her time with the help of pacers.

Traditional

Faith Kipyegon during the 2017 World Championships in Athletics in London. (Credit: Erik van Leeuwen/Wikimedia)

White

Faith Kipyegon during the 2017 World Championships in Athletics in London. (Credit: Erik van Leeuwen/Wikimedia)

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