Health

Months after Marshall Fire, returning residents reported symptoms, poor indoor air quality

Lisa Marshall — Mon, 23 Dec 2024 21:57:13 +0000

Months after Marshall Fire, returning residents reported symptoms, poor indoor air quality Lisa Marshall Mon, 12/23/2024 - 14:57

Lisa Marshall , Nicholas Goda

Six months after the Marshall Fire destroyed more than 1,000 houses in Boulder County, babyֱ��app, more than half of residents of surviving homes in the area reported physical symptoms—including headaches, sore throats or a strange taste in their mouth—that they attributed to poor air quality, a new CU Boulder study has found.

A companion study showed that the air quality inside one home post-fire equaled that of downtown Los Angeles in the 1990s on a high pollution day, with hazardous gases lingering for weeks.

“Our research suggests that there could be important health impacts for people returning to smoke- or ash-damaged homes after a fire and that we need to have systems in place to protect them,” said Colleen Reid, associate professor of geography and co-author of the studies.

Researchers test air quality inside a surviving home.

The papers, published this week in ACS Environmental Science & Technology Air, are the first to explore air quality inside smoke- and ash-damaged homes and to assess the health impacts on people who live in them. They come as fires in the Wildland-Urban Interface, like in Paradise, California, in 2018 and Lahaina, Hawaii, in 2023 grow more common.

“A lot of time has been spent studying wildfire smoke—what you get when you burn vegetation. But what do you get when you burn a home, with all its furniture and electronics and cars? Until now, there has been very little known,” said co-author Joost de Gouw, a professor of chemistry and fellow with the Cooperative Institute for Research in Environmental Sciences (CIRES).

A record winter blaze

Fueled by 100-mile-per-hour winds and record dry conditions, the Dec. 30, 2021, Marshall Fire burned 1,084 buildings in densely populated areas, took two lives and forced 37,000 people to evacuate.

Once residents returned home, scientists at CU Boulder, just 4 miles from the fire’s ignition, started getting calls.

“At first, they felt really lucky, but when they went into their homes they saw ash everywhere and it smelled differently—like a campfire or chemicals,” said Reid. “They asked: What should we do? We don’t know if it’s safe to go back in.”

With little research offering answers, the scientists began to investigate.

Ten days after the fire, de Gouw’s team erected field instruments in an intact home bordering a block where houses burned down. Over five weeks, they continually measured the presence of 50 gases. (Read more about the study here.)

Meanwhile, Reid and colleagues developed a survey to send to residents within the burn perimeter, as well as a random sample of those within 2 miles.

At six months, 642 people had responded; 413 had responded at the one-year mark.

Some 55% of respondents reported symptoms that they attributed to the fire at the six-month mark, and survey answers depended largely on the condition of their home when they returned home.

For instance, those who found ash inside were three times as likely to report headaches compared to those who didn’t find ash; those who reported an odd odor were four times as likely to report headaches compared to those who did not pick up an unusual scent.

People with the same symptoms tended to cluster together, according to computer mapping analyses. For example, those living near destroyed homes, especially in the direction the wind was blowing the day of the fire, were far more likely to report a strange taste in their mouth.

“These findings are consistent with chemical exposures and suggest that residents of smoke- and ash-damaged homes may have experienced lingering air quality and physical health challenges months after the fire,” said Reid.

Long-term impacts uncertain

The authors cannot say which chemicals caused the health impacts that survey respondents reported. But measurements in one home found high levels of volatile organic compounds (VOCs) like benzene, a carcinogen found in gasoline and diesel exhaust.

Dust samples also showed high levels of copper, zinc, arsenic and industrial pollutants called polycyclic aromatic hydrocarbons (PAHs), which are known to cause eye irritation.

“If your home survives, and the neighbor two doors down burns, all those melted things can get into the air and find their way into your home” settling into furnishings, carpets and drywall, said Reid.

The authors stress that VOCs are only considered carcinogenic at levels much higher than what they found, and people are regularly exposed to low levels daily through pollution.

Their research found that simple measures, like opening windows and using low-cost, carbon-activated air filters, can substantially improve air quality.

One year after the fire, the number of residents reporting symptoms had declined to just 33% and most said confidence in their home’s air quality had improved.

Until more studies are done, the researchers cannot say whether such exposures can lead to long-term health problems.

Nonetheless, Reid urges anyone going inside a smoke- or ash-damaged home just after a wildland urban interface (WUI) fire to use caution, wearing KN95 masks and gloves.

They hope their ongoing research can lead to clearer guidelines for policymakers and insurance companies about when it is safe for people to return to smoke-damaged homes.

“This wasn’t just any fire. It felt personal,” said de Gouw. “Knowing that we could at least begin to provide some answers to our community has made the work extra meaningful.”

Three years after the freak Dec. 30 blaze destroyed more than 1,000 homes in Boulder County, two new studies offer insight into what happens to air quality and health in the aftermath of urban wildfires.

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More than 1,000 homes burned in Boulder County during the Dec. 30, 2021, Marshall Fire. Credit: Joost de Gouw

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More than 1,000 homes burned during the Dec. 30, 2021 Marshall Fire. On the eve of the third anniversary, new research explores the health and air quality of those whose homes survived. Credit: Joost de Gouw

Could there be serious health risks with night-shift work?

Megan Maneval — Fri, 20 Dec 2024 19:50:36 +0000

Could there be serious health risks with night-shift work? Megan Maneval Fri, 12/20/2024 - 12:50

babyֱ��app Arts and Sciences Magazine

In a study she conducted while a CU Boulder postdoctoral researcher, Elizabeth Holzhausen and colleagues found a link between night-shift work and prostate-cancer risk.

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A THC breathalyzer? CU research could lead to reliable cannabis breath test

Lisa Marshall — Wed, 18 Dec 2024 15:03:33 +0000

A THC breathalyzer? CU research could lead to reliable cannabis breath test Lisa Marshall Wed, 12/18/2024 - 08:03

Lisa Marshall , Nicholas Goda

Law enforcement will be out in force this holiday season, with saturation patrols and sobriety checkpoints on the lookout for impaired drivers.

Professional research assistants Paige Xiaoying Phillips (left) and Gray MacDonald pose for a photo inside the mobile pharmacology lab, a.k.a. the Cannavan, at CU Boulder.

Yet 12 years after babyֱ��app and Washington became the first U.S. states to legalize recreational cannabis, police still lack a reliable method for detecting whether someone smoked a joint or ate a gummy recently and whether they are too impaired to drive.

Researchers at CU Boulder and the National Institutes of Standards and Technology (NIST) hope to help solve that problem, using a laboratory on wheels and state-of-the-art chemistry to map the peaks and declines of a cannabis high in real time.

Their new study of 45 regular cannabis users could help lead to standardized protocols for measuring impairment at the roadside and inform development of a new generation of cannabis breathalyzers.

“The ultimate goal is to develop a reliable tool that supports fair law enforcement and helps keep our roads safe,” said Cinnamon Bidwell, associate professor of psychology and neuroscience and co-director of CUChange, a lab that studies health risks and benefits of cannabis.

Needle in a haystack

Since the 1950s, police have measured ethanol in breath as an indicator of alcohol impairment. With cannabis, it’s more complicated.

Unlike ethanol, which is exhaled in copious amounts in a gaseous vapor, the main psychoactive ingredient in cannabis (tetrahydrocannabinol or

THC) is exhaled in trace amounts via tiny aerosol particles.

After consuming alcohol, a person exhales 1 million times more ethanol with a single breath than they would in 12 breaths after consuming cannabis, according to one NIST study.

“With THC, it’s like looking for a needle in a haystack,” said Tara Lovestead, a NIST chemical engineer who spearheaded that study.

THC also lingers in tissues, making it hard to discern with blood or breath whether someone used an hour ago or last week.

With alcohol, there is a clearly established BAC (blood alcohol concentration) above which someone is considered impaired (.08% in most states). Because there is no clear correlation between more THC in blood and breath and greater intoxication, there is no BAC equivalent for cannabis testing—yet.

Several cannabis breathalyzers exist on the market, some being tested by law enforcement. But it’s unclear whether they can be trusted, said Bidwell.

“Scientifically, we just aren’t there yet,” she said. “There are too many questions that need to be answered first in an unbiased setting. That’s what we’re trying to do.”

A two-breath test?

In a previous pilot study, the team concluded that while it’s possible to detect trace levels of cannabis in breath, a single breath measurement cannot reliably indicate when cannabis was used or whether that person is impaired.

That could leave the door open for someone to be wrongfully accused of driving under the influence.

“It’s a huge problem and a matter of social justice,” Bidwell said.

But what if you took multiple breath samples?

To test that approach, the research team will recruit regular cannabis users between age 25 and 50. Half will use a THC-based flower strain; the other half will use a THC-based concentrate. To ensure that participants use the same product, all will get their cannabis from the same dispensary, Native Roots Dispensary in Boulder, which has worked with CU Boulder on several research projects.

Because cannabis is federally illegal, researchers are not allowed to handle or administer it. So, Bidwell’s team uses a mobile pharmacology laboratory—a white Sprinter van equipped with specialized equipment—to bring the lab to the people.

“The van enables us to measure in real time the impact of legal market forms of cannabis that people actually use,” she said.

After undergoing a baseline test in the van, participants go inside their residence and use as much cannabis as they wish. Then they return to the van for 13 breath tests over two hours and a series of tests to gauge how high they feel.

Cinnamon Bidwell and her research team stand outside one of their "mobile pharmacology laboratories" - a.k.a. the Cannavan.

Lovestead and chemical engineer Kavita Jeerage, who leads the NIST team, will analyze the more than 1,200 unique samples to provide a clearer picture of what a baseline level of cannabis looks like in the breath of a regular user and how that number rises and falls as their level of intoxication changes.

While they don’t intend to develop their own cannabis breathalyzer, the research could be used to help others accurately interpret breath samples.

A BAC for THC

Previous research in blood suggests that levels of THC peak within about 15 minutes of use, before dropping precipitously for the next three hours.

In theory, if a driver were to take two breathalyzer tests 10 to 20 minutes apart after using cannabis, their second reading would be lower. If they hadn’t used recently, the two numbers would be the same.

The new study will determine whether that theory could be put into practice with a multi-breath test to determine recent use.

Subsequent studies could also help establish a BAC for THC, that could determine if someone is safe to drive when combined with other field tests.

The new test could be useful not only for police, but also for cannabis users themselves.

“Most people who use cannabis, whether for recreational or medical reasons, want to do so responsibly,” Bidwell said. “If there is a tool they can use to assure they aren’t putting anyone at risk, that would be hugely beneficial.”

Scientists at CU Boulder are using a mobile laboratory to collect 1,200 breath samples from cannabis users. The collaboration with the National Institutes of Technology could help lead to a reliable cannabis breathalyzer.

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Professional research assistant Gray MacDonald, left, works with a volunteer to demonstrate how breath collection works in the mobile pharmacology lab, also known as the Cannavan. The research team will collect 1,200 breath samples from cannabis users. Photo by Patrick Campbell/University of babyֱ��app

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Professional research assistant Gray MacDonald, left, works with a volunteer to demonstrate how breath collection works in the mobile pharmacology lab, a.k.a. the Cannavan. Photos by Patrick Campbell/CU Boulder

Why does the COVID-19 virus sicken some more than others? Discovery sheds light

Lisa Marshall — Thu, 12 Dec 2024 15:48:02 +0000

Why does the COVID-19 virus sicken some more than others? Discovery sheds light Lisa Marshall Thu, 12/12/2024 - 08:48

Lisa Marshall

Why does the COVID-19 virus make some people sicker than others?

For years, scientists have looked to a critical piece of immune system machinery—known as the interferon pathway—for answers. There, when our cells sense an infection, they release a protein known as interferon, which warns other cells to fight the virus.

Studies show that when this signaling goes awry and leads the body to under or overreact, people are more likely to develop severe or Long COVID. Glitches in this pathway have also been implicated in autoimmune diseases and cancer.

But little is known about what, precisely, drives these immunological misfires.

Assistant Professor Ed Chuong

A new CU Boulder study, published today in the journal Cell, sheds light on the subject by identifying what the authors describe as an “immune system tuning dial,” which originated as a bug in the genetic code tens of millions of years ago.

“We’ve discovered that there is an entire class of under-appreciated protein variants that can have an immense impact on our immune function,” said senior author Ed Chuong, an assistant professor in the Department of Molecular, Cellular and Developmental Biology and the BioFrontiers Institute.

His lab demonstrated that one particular variant of a protein called IFNAR2 acts like a tuning dial to regulate interferon signaling.

“If we can manipulate this dial to turn the immune system up or down it could have broad therapeutic applications, from infection to autoimmune disorders to cancer.”

How evolution turned a bug into a feature

Chuong studies transposons, bits of DNA that infiltrated primate cells as many as 70 million years ago and now make up more than half of the human genome.

Some transposons, known as endogenous retroviruses, got there via ancient viruses. When reawakened, these genetic parasites can help cancer survive and thrive. Others, like the ones explored in the new paper, emerged from the genome itself, like random bugs popping up in a computer program’s source code.

“If you think of a gene as a sentence, a transposon is like a word that jumps into the sentence, making the instructions for the cell slightly different,” explained first author Giulia Pasquesi, a postdoctoral researcher in Chuong’s lab.

Cells normally suppress these bugs, ensuring only the correct version of the gene is spurred into action. So scientists have long viewed them as inert ‘junk DNA’.

Pasquesi set out to challenge this assumption, looking for gene variants formed by transposons that were actually important for human immune function.

When she analyzed state-of-the-art genetic sequencing data from human tissues and cells, she found 125 instances across 99 genes.

A break in the antenna

Pasquesi and Chuong focused on a variant of interferon receptor 2 (IFNAR2)—a critical protein which acts like a cellular antenna for interferon, turning on other genes that fight off infection and cancer. They found that the new “short” variant could sense interferon, but it was missing parts required to transmit the signal. Surprisingly, it was present in all cells, and often more abundant than the normal protein suggesting it played an important role in immunity.

They followed up with experiments using cells with different combinations of the two IFNAR2 varieties. When they exposed them to immune challenges, including viral infections, they found that the short variant acted as a “decoy” that interferes with normal IFNAR2 signaling. When they removed the short variant from the genome, cells became much more sensitive to interferon, with stronger immune responses against viruses including SARS-CoV-2 and dengue virus.

The findings suggest that the balance between IFNAR2 variants acts as a “tuning dial” for controlling the strength of immune signaling, and this can vary from person to person. Individuals who express abnormally high levels of the variant might be more susceptible to severe infections, while people expressing low levels may have chronic inflammation, autoimmune issues like psoriasis or irritable bowel syndrome, or Long COVID.

“Different individuals are well known to exhibit differences in their immune responses, but the reasons why are still poorly understood. We’ve uncovered a new control dial that could be behind some of this variation,” said Chuong.

The team has filed for a provisional patent and begun developing and testing compounds to therapeutically target the dial.

Bigger picture, they believe that the story of IFNAR2 is the tip of the iceberg, and many other immune functions may be regulated by these long-ignored genomic hitchhikers.

“Our findings suggest that looking into the dark corners of the genome is key to making new discoveries to improve human health,” said Chuong.

Researchers have discovered a protein variant that serves as a knob for regulating the body’s innate immune response. The findings could lead to new therapies for Long COVID, autoimmune disorders and more.

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Giulia Pasquesi, right, a postdoctoral researcher at the BioFronties Institute, works in the lab with staff scientist David Simpson.

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Giulia Pasquesi, right, a postdoctoral researcher at the BioFrontiers Institute, works in the lab.

CUriosity: What does an all-nighter do to your body?

Daniel William Strain — Wed, 04 Dec 2024 22:01:00 +0000

CUriosity: What does an all-nighter do to your body? Daniel William… Wed, 12/04/2024 - 15:01

Lisa Marshall

In CUriosity, experts across the CU Boulder campus answer pressing questions about humans, our planet and the universe beyond.

This week, Integrative Physiology Professor Ken Wright, answers: “What does an all-nighter do to your body?”

Credit: Adobe Stock

Previously in CUriosity

Should you trust 5-star reviews?

Whether we’re cramming for finals, catching a red-eye flight, binge-watching rom-coms, or indulging in a bit too much cheer, the holiday season can wreak havoc on sleep.

Surveys suggest that more than half of U.S. adults stay up all night at least once during the year, and one in five college students report pulling an all-nighter monthly. But can just one night of missed sleep really hurt us?

“Absolutely,” said Integrative Physiology Professor Ken Wright, director of the Sleep and Chronobiology Laboratory at CU Boulder. “Pulling an all-nighter is a significant stressor, both physiologically and cognitively, to the body.”

Over the past two decades, Wright has invited countless paid volunteers into his lab for days-long, tightly controlled experiments. In one six-day study of healthy males in their 20s, he found that staying up all night and sleeping all day just once disrupted the levels and timing of 129 key proteins circulating in the blood, including those that regulate appetite and energy, keep blood sugar in check and fend off illness.

Exposure to light when the body is accustomed to darkness can also throw off the timing of hormones, including melatonin (which, among other things, signals our body that it’s time to rest) and cortisol (the “stress hormone”). These shifts can disrupt our body clock, or circadian rhythm, making it harder to sleep when we want to.

Eating at a time when our body is not ready to process food can promote weight gain and boost Type-II diabetes risk—as studies show we store more calories as fat and are less efficient at turning sugar into energy at night.

Ken Wright

“A calorie is not just a calorie. If you eat junk food in the middle of the night, it can be even worse for you than eating that same junk food during the day,” said Wright.

The immune system also stands down, even when we are awake, during our “biological night” (a time when our body is conditioned to rest and recover and is not typically exposed to pathogens.) This makes us more vulnerable to injury and illness if they hit us in the wee hours of morning.

For instance, one study by another research team found that humans heal 60% faster when they sustain wounds during the day than at night. Another study found that when scientists exposed mice to viruses when they were supposed to be resting, those pathogens replicated 10 times faster than in mice infected during waking hours.

“Timing matters,” said Wright. “If you are awake in the middle of the night and you’re exposed to someone who is sick, you have an increased risk of getting sick.”

Lack of sleep can also do a number on our thinking the next day, with research showing that skipping a night’s sleep is about the same as having a 0.08 blood alcohol level.

“If you drive after staying up all night, it is the equivalent of driving drunk,” Wright warned.

The sleep scientist has some advice for students cramming for finals: Don’t wait until the night before your test and stay up studying until dawn. Instead, study days prior to a test and review your notes right before bed because sleep can help consolidate your memories. If you do have to stay up late, make sure your midnight snack is as healthy as possible and avoid driving the next day.

Your body will thank you, and your grades might, too.

Being awake when your body thinks you should be sleeping can make you more susceptible to viruses, make your wounds heal more slowly and promote weight gain. And don't even think about driving the day after an all-nighter.

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Females sleep less, awaken more frequently than males

Lisa Marshall — Wed, 20 Nov 2024 15:10:34 +0000

Females sleep less, awaken more frequently than males Lisa Marshall Wed, 11/20/2024 - 08:10

Lisa Marshall

Females sleep less, wake up more often and get less restorative sleep than males, according to a new animal study by CU Boulder researchers.

The findings, published in the journal Scientific Reports, shed new light on what may underlie sleep differences in men and women and could have broad implications for biomedical research, which for decades has focused primarily on males.

“In humans, men and women exhibit distinct sleep patterns, often attributed to lifestyle factors and caregiving roles,” said senior author Rachel Rowe, assistant professor of integrative physiology. “Our results suggest that biological factors may play a more substantial role in driving these sleep differences than previously recognized.”

Sleep research has exploded in recent years, with thousands of animal studies exploring how insufficient sleep impacts risk of diseases like diabetes, obesity, Alzheimer’s and immune disorders—and how such diseases impact sleep. Meanwhile, mice have often been the first to be tested to see whether new drugs, including medications for sleep, work and what the side effects are.

But many of those results may have been skewed due to a lack of female representation, the study suggests.

“Essentially, we found that the most commonly used mouse strain in biomedical research has sex-specific sleep behavior and that a failure to properly account for these sex differences can easily lead to flawed interpretations of data,” said first author Grant Mannino, who graduated with degrees in psychology and neuroscience and was named outstanding undergraduate of the College of Arts and Sciences in May.

How mice sleep

For the non-invasive study, the authors used specialized cages lined with ultrasensitive movement sensors to assess the sleep patterns of 267 “C57BL/6J” mice.

Males slept about 670 minutes total per 24-hour period, about an hour more than female mice. That extra sleep was non-Rapid Eye Movement (NREM) sleep—the restorative sleep when the body works to repair itself.

Mice are nocturnal and are “polyphasic sleepers”—napping for a few minutes before arousing briefly to survey their environment and then resuming their slumber. Females, the study found, have even shorter bouts of sleep—essentially, their sleep is more fragmented.

Similar sex differences have been seen in other animals, including fruit flies, rats, zebrafish and birds. Evolutionarily, it makes sense.

“From a biological standpoint, it could be that females are designed to be more sensitive to their environment and be aroused when they need to be because they are typically the one who is caring for the young,” Rowe said. “If we slept as hard as males sleep, we would not move forward as a species, right?”

Rachel Rowe

Stress hormones like cortisol (which promotes wakefulness) and sex hormones likely play a role. For instance, women tend to report worse sleep during the time in their menstrual cycle when estrogen and progesterone are at their lowest.

Some have hypothesized that females inherently require less sleep.

“For me, the question is: Are we creating too much stress for ourselves because we don’t sleep as much as our husband or partner and think our sleep is poor when actually that is a normal sleep profile for ourselves?” said Rowe.

The authors hope their findings inspire more research into underlying biological differences. More importantly, they hope the study prompts scientists to re-evaluate how they do research.

Progress made but more work to be done

In 2016, the National Institutes of Health began requiring scientists applying for funding for animal studies to consider “sex as a biological variable.” Progress has been made, but research has shown that sex bias still exists. And it can have real consequences, the authors found.

When they simulated a sleep treatment that worked best in females, they found that it was accurately reflected only if the sample size was made up evenly of males and females.

Bottom line: If females are underrepresented, drugs that work best for them may seem ineffective, or side effects that hit hardest may go unnoticed.

“The pipeline from bench to bedside is decades-long and often things that work in animals fail when they get to clinical trials. Is it taking so long because sex isn’t being considered enough?” said Rowe.

The authors encourage researchers to include both sexes equally when possible, analyze data for males and females separately, and re-evaluate past studies that underrepresented females.

“The most surprising finding here isn’t that male and female mice sleep differently. It’s that no one has thoroughly shown this until now,” said Rowe. “We should have known this long before 2024.”

Females sleep less, wake up more often and get less restorative sleep than males, according to a new study. The findings could have broad implications for biomedical sleep research, which for decades has focused primarily on males.

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Detecting cognitive decline before its symptoms start

Megan Maneval — Mon, 18 Nov 2024 13:56:32 +0000

Detecting cognitive decline before its symptoms start Megan Maneval Mon, 11/18/2024 - 06:56

babyֱ��app Arts and Sciences Magazine

In his research on the brain, Daniel Gustavson looks for clues about when cognitive decline begins. Gustavson is an assistant research professor in the Institute for Behavioral Genetics.

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Social media posts reveal regional patterns in seasonal allergies

Megan Maneval — Fri, 15 Nov 2024 15:52:54 +0000

Social media posts reveal regional patterns in seasonal allergies Megan Maneval Fri, 11/15/2024 - 08:52

CIRES

Scientists from CIRES and CU Boulder harnessed social media data to track patterns in allergy intensity across the United States, finding an allergy hotspot in the Southeastern U.S., a winter allergy season in babyֱ��app and more.

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Prolonged sitting can sabotage health, even if you’re young and active

Daniel William Strain — Thu, 31 Oct 2024 21:38:57 +0000

Prolonged sitting can sabotage health, even if you’re young and active Daniel William… Thu, 10/31/2024 - 15:38

Lisa Marshall

Between long commutes, Zoom-packed workdays and evenings of streaming and scrolling, millennials now spend more than 60 hours per week sitting, potentially boosting their heart disease risk and accelerating other signs of aging, according to new CU Boulder and University of California Riverside research.

The study of more than 1,000 former or current babyֱ��app residents, including 730 twins, is among the first to explore how prolonged sitting impacts health measures such as cholesterol and body mass index (BMI) in young adults.

It found that meeting the minimum recommended physical activity guidelines—about 20 minutes per day of moderate exercise—isn’t enough to counter the hazards of spending most waking hours in a seat.

“Our research suggests that sitting less throughout the day, getting more vigorous exercise, or a combination of both may be necessary to reduce the risk of premature aging in early adulthood,” said the study’s senior author Chandra Reynolds, a professor in the Department of Psychology and Neuroscience and the Institute for Behavioral Genetics.

Chandra Reynolds

For the study, published in the journal PLOS ONE, Reynolds teamed up with first author Ryan Bruellman, a doctoral candidate in the Department of Genetics, Genomics and Bioinformatics at UC Riverside.

After the COVID pandemic, Bruellman noticed that he and other people his age were sitting more. He set out to learn more about the consequences.

“Young adults tend to think they are impervious to the impacts of aging. They figure, ‘My metabolism is great, I don’t have to worry until I’m in my 50s or 60s,’” said Bruellman. “But what you do during this critical time of life matters.”

A walk after work isn’t enough

The authors analyzed data from participants ranging in age from 28 to 49, average age 33, from CU’s babyֱ��app Adoption/Twin Study of Lifespan behavioral development and cognitive aging (CATSLife), which has followed twins and adopted individuals since childhood.

On average, participants reported sitting almost 9 hours daily, with some sitting as much as 16 hours. They reported between 80 and 160 minutes of moderate physical activity on average weekly and less than 135 minutes of vigorous exercise weekly. The authors note that these results are likely better than national averages due to babyֱ��app’s active lifestyle.

The researchers looked at two key measures of heart and metabolic aging: total cholesterol/high-density lipoprotein and body mass index (BMI). The study found that, essentially, the more one sat, the older one looked. And adding a little moderate activity on top of a long day of sitting did little to buffer these impacts.

In fact, young adults who sat 8.5 hours per day and performed at or below current exercise recommendations could enter a “moderate to high risk” category for cardiovascular and metabolic disease, the authors said.

“Taking a quick walk after work may not be enough,” said Reynolds. “While this is increasingly apparent with age, we show that associations are already emerging in early adulthood.”

Adding vigorous activity did have a buffering effect.

For instance, those who exercised vigorously (think running or cycling) for 30 minutes daily had cholesterol and BMI measures that looked like those of individuals five to 10 years younger who sat as much as they did but didn’t exercise.

But even vigorous activity could not fully buffer the negative impacts of prolonged sitting, the study concluded.

Same genes, different lifestyles

Identical twins are particularly useful to study because they share 100% of their genes, making it easier to rule out genetic factors that might contribute to different health outcomes and zero in on lifestyle differences.

When looking at a subset of twins with different sitting and physical activity habits, the researchers found that replacing sitting with exercise seemed to work better to improve cholesterol than simply adding exercise to a full day of sitting.

Bottom line, the researchers said: Try to do both.

Use a standing desk, take breaks and organize walking meetings to reduce sitting time at work. If possible, do something that gets you out of breath for at least 30 minutes per day, or be a “weekend warrior” getting in a longer, vigorous workouts when you can, said Bruellman.

He hopes the study will serve as a call to action for policymakers to revisit physical activity guidelines and specify how much sitting is too much.

Meanwhile, Reynolds encourages young adults to take steps now that could shape their future:

“This is the time to build habits that will benefit health over the long term.”

Young adults sit 60-plus hours per week, boosting their heart disease risk and accelerating signs of aging, according to new research. Vigorous exercise works best to counteract it, but sitting less is ideal.

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CUriosity: What causes the runner’s high?

Anonymous — Wed, 23 Oct 2024 19:33:54 +0000

CUriosity: What causes the runner’s high? Anonymous (not verified) Wed, 10/23/2024 - 13:33

Lisa Marshall , Nicholas Goda

In our new, bi-weekly series CUriosity, experts across the CU Boulder campus answer pressing questions about humans, our planet and the universe beyond.

This week, Psychology and Neuroscience Professor Angela Bryan, answers: “What causes the runner’s high?” (Hint: It may not be what you think.)

Runners cross the Verrazano Narrows Bridge in New York City. More than 51,000 runners will line up for this year's New York Marathon November 3. (Credit: CC photo via Wikimedia Commons)

It can set in after just a few miles: Nagging aches grow numb, sense of time slips away, colors brighten and thoughts grow crisp. Afterward, runners say they feel less anxious, stronger and more confident—even euphoric.

Previously in CUriosity

Why does playing in the dirt feel so good?

But what causes this legendary “runner’s high?”

For decades, scientists have suspected that endorphins and other “endogenous opioids”—pain killers made by our own bodies—are at play, coursing through our blood stream when we work out and attaching to the same receptors in the brain that drugs like morphine or oxycodone do.

But, Bryan says, running may actually be more like smoking a joint than taking a pain pill.

“For a long time, everybody thought that the runner’s high was caused by the activation of the endogenous opiate system, but we are now beginning to think it is actually the endogenous cannabinoid system instead,” she explains.

She would know: The psychologist often starts the morning with a run, then heads into her lab where she studies how cannabis, a.k.a. weed, affects the human body.

Cannabinoids are essentially the active ingredients in cannabis. Some “exogenous” (from outside the body) cannabinoids, like THC (tetrahydrocannabinol), promote intoxication. Others, like CBD (cannabidiol) quell inflammation and anxiety. The human spinal column and brain are rich in cannabinoid receptors that these compounds attach to when someone eats a gummy or smokes cannabis flower.

But we also make our own.

Standing on the Boulder Creek path, her face glowing after a morning jog, Bryan explains:

“I feel amazing. It’s just this feeling of freedom and strength and confidence,” she says as a pack of runners shuffles by. “Everyone we are seeing out here today is having that same experience, and I would be willing to bet that none of them used cannabis before their run today.”

When we exert ourselves, our tissues release cannabinoids which slip perfectly into those same receptors, reducing pain and sparking euphoria.

As Bryan notes in one review paper, long-distance runners often describe running as a “drug like” experience (complete with difficulty assessing the passage of time). They also experience something akin to withdrawal when they can’t run.

Numerous studies have shown that high-intensity exercise (running more so than walking) leads to higher circulating levels of endocannabinoids in the blood.

Meanwhile, studies have begun to debunk the endorphin-runner’s high connection.

One found that when opioid receptors were chemically blocked with a drug called naltrexone, athletes still experienced the runner’s high. Another found that when cyclists had higher circulating levels of endorphins, they actually felt more, not less, stressed out.

While it’s not necessary to use cannabis to get the runner’s high, many athletes, particularly ultra long-distance runners, do mix weed and workouts. They report that supplementing the cannabinoids their bodies make with ones from a dispensary can enhance the high or bring it on sooner.

But there are downsides to that.

In one study of 42 runners published in the journal Sports Medicine, Bryan found that using THC or CBD during exercise did indeed boost motivation and make exercise more fun. But it also slowed folks down.

Her advice for those gunning for a fast 5k or a marathon PR: Stick with the high your own body gives you.

Psychologist Angela Bryan, like many other avid runners, is no stranger to what many call the “runner’s high.” The scientist breaks down what happens in the body to make you feel so good during a long jog.

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