The Brief

Phoenix heat is notorious for the harm it causes in the short-term, like heat stroke and heart problems. Just last year, temperatures there topped 90 degrees Fahrenheit for a record-breaking 188 days. More than 140 of those days surpassed 100 degrees.

A new study published in Science Advances shows that prolonged heat exposure of that magnitude can even modify how people's genes behave, speeding up aging at the molecular level and potentially impacting people's long-term health.

The impact is "similar to the effect of smoking and drinking," says Eunyoung Choi, a gerontologist at the University of Southern California's Leonard Davis School of Gerontology and the study's lead researcher.

The study looked at people over 56 living across the country with very different heat experiences. People from extremely hot parts of the country like Phoenix — where the heat index, a combination of temperature and humidity — topped 90 degrees for more than half the year, looked biologically about 14 months older, epigenetically, than similar people living in cooler places like Seattle, where fewer than 10 days of each year exceed that threshold.

That may not sound like an enormous difference, says Boston University gerontologist Deborah Carr, who wasn't involved in the study, but for the person affected, "it's just a tremendous strain not only on their own lives and the lives of their families and caregivers, but also has a larger societal impact."

Research links premature aging with an earlier onset of health issues like dementia, diabetes and cardiovascular disease. The sooner those symptoms begin, the more of a toll they take on people's well-being and productivity, Carr says.

"If that's something that takes you out of the workforce for a year, that makes you go to the doctors every day for a year, that increases your medication budget — it really can have tremendous impacts," she explains.

Epigenetic aging

The researchers tracked the biological age of people in their study by looking for subtle changes in their DNA after different periods of exposure to heat, from a few days of extreme temperatures to several years.

"We know that some people seem to age faster than others, and that's because biological aging doesn't always match chronological aging," Choi says.

Biological age is often correlated with chemical tags that accumulate and are shed from people's DNA over time, a process called methylation; it is often referred to as "epigenetic aging." "DNA methylation acts like a light switch for genes — so it can turn them on and off," Choi says.

Methylation doesn't change the genes themselves, but modifies the way those genes work — sometimes for the better, but oftentimes not. Many studies in both animals and humans have shown that DNA methylation patterns change over time and can be used as a sort of molecular clock, ticking along as people age.

Epigenetic aging can accelerate because people don't eat well or don't get enough exercise. But it is also associated with emotional or physical stress, as well as exposure to environmental harms like air pollution "and, in this case, heat," Choi says.

The researchers looked at blood samples from more than 3,600 older adults across the U.S. and assessed people's epigenetic age. They could figure out how much heat those people experienced over a few days, a few months, one year and six years prior to that sample collection using climate and weather models looking into the past, taking into account both temperature and humidity — factors that influence the danger of different heat conditions.

The outcomes were clear. People who experienced more heat over the long-term aged faster, biologically, than those living in cooler places. That's even after taking into account people's financial status, education, physical activity and whether they smoked.

Researchers have known for years that heat exposure correlates with long-term issues like worsened risk of cardiac problems. But "the mechanisms for how that happens haven't been clear," says Tom Clanton, a physiologist and heat expert at the University of Florida's College of Health and Human Performance, who wasn't involved in the research. This work, he says, begins to explain how those delayed effects might happen. At the genome level, heat exposure makes "you sort of accelerate your way towards an old heart, and an old vulnerable heart," he says.

Climate pressures

Heat causes plenty of shorter-term health problems for people of all ages. The number of emergency department visits rises during heat waves, as does the number of cardiovascular issues, kidney problems and even deaths not directly linked to the heat.

The risks rise as human-driven climate change accelerates, says Choi. The number of extreme heat days in the U.S. could rise by 20 to 30 days across much of the country by the middle of the century, according to the country's National Climate Assessment, a comprehensive accounting of past and potential future changes to the country because of climate change.

At the same time, as heat risks grow because of climate change, Carr says, the U.S. population is aging. Older people's bodies generally deal with heat less adeptly than younger people. Sweating capacity decreases. Less blood flows to the skin where it can be cooled. Some medications interfere with people's ability to manage heat.

But heat makes life harder for everybody, not just older people, says Robert Meade, a heat physiology expert at Harvard University's T.H. Chan School of Public Health. "It's basically like if you're trying to tread water and someone hands you a brick," he says. "It's extra strain on all your physiological systems. It's just an extra weight that needs to be responded to in order to maintain homeostasis."

The next step to connect heat exposure to specific health problems, Meade thinks, is to further personalize the analyses, because even within the hottest parts of the country, people experience very different heat exposures. "What people actually experience in their homes, whether they're in an overheated mobile unit or they have air conditioning available, can be wildly different temperatures," he says.

Researchers indicate that the next frontier of this work should look at how heat exposure within people's homes shapes health outcomes. That kind of specific, personalized risk assessment could help scientists further pinpoint exactly how heat hurts people, Meade says — and maybe even how to prevent the damage or reverse it.
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After copper wire theft left the Sixth Street Bridge in darkness for years, the city of Los Angeles has hired a Pasadena-based engineering firm to restore the lighting, a move aimed at improving safety for Boyle Heights and the surrounding neighborhoods.

City officials contracted Tetra Tech to relight the bridge, which has been plagued by copper wire theft since its opening in 2022. The outages have frustrated residents and commuters who use the bridge to walk, run, bike and drive between downtown LA and the Eastside.

Aging infrastructure, copper wire theft and delayed repairs led to nearly 2,000 streetlight service requests in Boyle Heights in 2024. Nearly seven miles of copper wire have been reported stolen from the Sixth Street Bridge.

Tetra Tech began working on the project’s design in January and is scheduled to restore the wiring to all lights along the bridge, including along roadways, barriers, ramps, stairways and arches before the 2028 Olympic and Paralympic Games come to Los Angeles that summer, according to a Feb. 18 news release from Councilmember Ysabel Jurado’s office.

The firm – which was selected by the city’s Bureau of Engineering – will fortify the pull boxes, service cabinet and conduits to protect against copper wire theft. Tetra Tech will also install a security camera system to deter vandalism and theft.

“When our streets are well-lit, our neighborhoods feel safer and more connected,” Jurado said in the news release. “The Sixth Street Bridge plays a vital role in connecting Angelenos between the Eastside and the heart of the City.”

Jurado – who pledged to look into fixing the Sixth Street Bridge lights when she was elected in 2024 – said the partnership with Tetra Tech “moves us one step closer to restoring one of the City’s most iconic landmarks as a safe, welcoming public space our communities deserve.”

According to officials, the total contract value with Tetra Tech is $5.3 million, which includes work on the Sixth Street Bridge as well as the Sixth Street PARC project, which encompasses 12 acres of recreational space underneath and adjacent to the bridge.

The PARC project will make way for sports fields, fitness equipment, event spaces and a performance stage. PARC’s grand opening is anticipated later this year.

Because the work for the PARC project and the bridge is connected, the Board of Engineers recommended using the existing PARC contract with Tetra Tech to ensure completion ahead of the 2028 Games, officials said.

The cost for the design work on the bridge alone is roughly $1 million.

On Thursday, Jurado announced that her streetlight repair crew had restored lighting and strengthened infrastructure for more than 400 streetlights across her district, including Boyle Heights, Lincoln Heights, and El Sereno. Next, they plan to tackle repairs in downtown L.A.

For the last 70 years, the  27th Street Bakery hasn’t just been the go-to place for people who want to spend less time in the kitchen — it’s become a staple in South Central, providing jobs and security for people living in the neighborhood.

The bakery is Black-owned and in its third generation as a business. It’s co-owned by sisters Denise Cravin-Paschal and Olympic gold-medalist Jeanette Bolden-Pickens, as well as her husband Al Pickens.

“My grandfather employed a lot of people around here as he was growing his business and so have we,” Cravin-Paschal told the LA Local. “They feel that this is a safe place to come. We have the respect of being here for 70 years and so we enjoy it.”

The bakery sits on Central Avenue, the focal point of Black Los Angeles between the 1930s and 1960s. As segregation laws were struck down, Black people in LA began to move elsewhere and took their businesses with them. The bakery, though, is still Black-owned and operating 70 years later.

Today it is considered the largest manufacturer of sweet potato pies on the West Coast, the bakery’s website states. Last year, the city and District 9 Councilmember Curren Price Jr. presented the bakery with a plaque that reads: “A Walk Down Central Avenue — A legacy of community: powered by the people and its places.”

It hangs on the wall in the bakery’s lobby along with several other photos and recognitions they’ve received over the years.

“Our goal is to keep this legacy alive and we’re celebrating 70 years of being here in business. We are so grateful to the community,” Bolden-Pickens said.

In celebration of its anniversary, a sign in the bakery says it is offering one slice of sweet potato pie for 70 cents on Saturdays starting this weekend through Oct. 31.

The bakery was a restaurant at first bringing Southern flavor to LA

The bakery began as a restaurant in the 1930s on Central Avenue founded by Harry and Sadie Patterson, according to the family and Los Angeles Conservancy. Back then, Central Avenue was the epicenter of LA’s Black community and Patterson, who came from Shreveport, Louisiana, decided to bring his Southern recipes to life in Los Angeles.

The restaurant later became a bakery in 1956, according to the bakery’s website. Patterson’s daughter Alberta Cravin and her son Gregory Spann took over the bakery in 1980. After Spann passed away, Cravin’s daughters — the sisters who are current owners — took over the family business. Five other relatives also help them out, Cravin-Paschal said.

These days, the bakery is open Tuesday through Saturday each week and the bulk of their customers are other businesses. They serve nearly 300 vendors including convenience stores like 7-Eleven, Ralphs grocery stores, Smart & Final, ARCO gas stations, restaurants and other mom-and-pop stores. Louisiana Fried Chicken has been a customer since 1980, Cravin-Paschal said.

An average delivery today is usually 45 dozen pies and they also ship orders out of state, Cravin-Paschal said.

She also told The LA Local they have six full time employees and most of them have worked for the bakery at least 25 years.

“I like working here, I like the people,” Maximina “Maxi” Rodriguez, a longtime employee, told The LA Local. After 32 years at the bakery, she said she plans to retire in June. “I’m going to miss it.”

Rodriguez said working at the bakery is a family affair for her, too. Her sister, Guadalupe Garibaldi, has worked at the bakery for over 40 years and her niece, Yoselin Garibaldi, is now a cashier and driver.

Patterson’s lessons inspired 3 generations to keep the business running

For Bolden-Pickens and Cravin-Paschal, running the bakery is a labor of love. Both told The LA Local that their grandfather taught them to stay true to the fresh ingredients they use and not to cut corners.

These lessons helped Bolden-Pickens in her life before taking over the family business. She won a gold medal as part of the U.S. 4×100 meter relay team in track and field during the 1984 Olympics.

“What I learned from being an Olympian is that it takes a lot of hard work. I learned that from my grandfather,” she said.

Bolden-Pickens said it hasn’t been easy running the business, but they’ve been able to stay afloat because of the lessons learned from their grandfather.

“I remember during the pandemic, we actually had to go to the egg farm and stand in line for a couple of hours just to get the eggs that we needed,” Bolden-Pickens said. “We use the best spices. We make our own vanilla.”

Cravin-Paschal said after the death of their brother Gregory Spann, who was the main baker for nearly two decades, they struggled for a few years to keep the recipe and taste consistent. But eventually they figured it out.

“We had a little rough spot because we all know the recipes but you have to put it together (correctly),” Cravin-Paschal said. “Now we’re back to the original taste.”

As marijuana use among teens has grown in the past decade, researchers have been trying to better understand the health risks of the drug. Now, a new longitudinal study finds that cannabis use among adolescents increases risks of being diagnosed with bipolar and psychotic disorders, as well as anxiety and depression, years later.

"This is very, very, very worrying," says psychiatrist Dr. Ryan Sultan at Columbia University, a cannabis researcher who wasn't involved in the new study published in the latest JAMA Health Forum.

Strong study design

Researchers analyzed health data on 460,000 teenagers in the Kaiser Permanente Health System in Northern California. The teens were followed until they were 25 years old. The data included annual screenings for substance use and any mental health diagnoses from the health records. Researchers excluded the adolescents who had symptoms of mental illnesses before using cannabis.

"We looked at kids using cannabis before they had any evidence of these psychiatric conditions and then followed them to understand if they were more likely or less likely to develop them," says Dr. Lynn Silver, a pediatrician and researcher at the Public Health Institute, and an author of the new study.

They found that the teens who reported using cannabis in the past year were at a higher risk of being diagnosed with several mental health conditions a few years later, compared to teens who didn't use cannabis.

Teens who reported using cannabis had twice the risk of developing two serious mental illnesses: bipolar, which manifests as alternating episodes of depression and mania, and psychotic disorders, such as schizophrenia which involve a break with reality.

Now, only a small fraction — nearly 4,000 — of all teens in the study were diagnosed with each of these two disorders. Both bipolar and psychotic disorders are among the most serious and disabling of mental illnesses.

"Those are the scarier conditions that we worry about," says Sultan.

Silver points out these illnesses are expensive to treat and come at a high cost to society. The U.S. cannabis market is an industry with a value in the tens-of-billions — but the societal cost of schizophrenia has been calculated to be $350 billion a year.

"And if we increase the number of people who develop that condition in a way that's preventable, that can wipe out the whole value of the cannabis market," Silver says.

Depression and anxiety too

The new study also found that the risk for more common conditions like depression and anxiety was also higher among cannabis users.

"Depression alone went up by about a third," says Silver, "and anxiety went up by about a quarter."

But the link between cannabis use and depression and anxiety got weaker for teens who were older when they used cannabis. "Which really shows the sensitivity of the younger child's brain to the effects of cannabis," says Silver. "The brain is still developing. The effects of cannabis on the receptors in the brain seem to have a significant impact on their neurological development and the risk for these mental health disorders."

Silver hopes these findings will make teens more cautious about using the drug, which is not as safe as people perceive it to be.

"With legalization, we've had a tremendous wave of this perception of cannabis as a safe, natural product to treat your stress with," she says. "That is simply not true."

The new study is well designed and gets at "the chicken or the egg, order-of-operations question," says Sultan. There have been other past studies that have also found a link between cannabis use and mental health conditions, especially psychosis. But, those studies couldn't tell whether cannabis affected the likelihood of developing mental health symptoms or whether people with existing problems were more likely to use cannabis — perhaps to treat their symptoms.

But by excluding teens who were already showing mental health symptoms, the new study suggests a causal link between cannabis use and later mental health diagnoses. Additional research is needed to understand the link fully.

'Playing with fire'

Sultan, the psychiatrist and researcher at Columbia University, says the study confirms what he's seeing in his clinic — more teens using cannabis who've developed new or worsening mental health symptoms.

"It is most common around anxiety and depression, but it's also showing up in more severe conditions like bipolar disorder and psychosis," he says.

He notes that mental health disorders are complex in origin. A host of risk factors, like genetics, environment, lifestyle and life experiences all play a role. And some young people are more at risk than others.

"When someone has a psychotic episode in the context of cannabis or a manic episode in the context of cannabis, clinicians are going to say, 'Please do not do that again because you're you're you're playing with fire,'" he says.

Because the more they use the drug, he says the more likely that their symptoms will worsen over time, making recovery harder.

"What we're worried about [is if] you sort of get stuck in psychosis, it gets harder and harder to pull the person back," says Sultan. "Psychosis and severe mood disorders, particularly bipolar disorder are like seizures in your brain. They're sort of neurotoxic to your brain, and so it seems to be associated with a more rapid deterioration of the brain."

Some electric bikes in California could soon require license plates under a proposed state bill aiming to address the rise in electric bike related injuries.

AB 1942 or the E-bike Accountability Act, would apply exclusively to Class 2 and Class 3 electric bikes.

Class 2 bikes can be operated without peddling until it reaches the speed of 20 mph.

Class 3 bikes reach a max speed of 28 mph; motor assist could only kick in with peddling.

The bill would also require owners to carry proof of ownership and would direct the Department of Motor Vehicles to establish a registration process. It was introduced by Assemblymember Rebecca Bauer-Kahan of Orinda in Contra Costa County earlier this month.

E-bike injuries spiked 18-fold between 2018 and 2023, according to state traffic data.

The bill may be heard in committee March 16.