Science
Older People Seeking Care for Cannabis Use at Greater Risk for Dementia, Study Finds
Middle-aged and older adults who sought hospital or emergency room care because of cannabis use were almost twice as likely to develop dementia over the next five years, compared with similar people in the general population, a large Canadian study reported on Monday.
When compared with adults who sought care for other reasons, the risk of developing dementia was still 23 percent higher among users of cannabis, the study also found.
The study included the medical records of six million people in Ontario from 2008 to 2021. The authors accounted for health and sociodemographic differences between comparison groups, some of which play a role in cognitive decline.
The data do not reveal how much cannabis the subjects had been using, and the study does not prove that regular or heavy cannabis use plays a causal role in dementia.
But the finding does raise serious concerns that require further exploration, said Dr. Daniel T. Myran, the first author of the study, which was published in JAMA Neurology.
“Figuring out whether or not cannabis use or heavy regular chronic use causes dementia is a challenging and complicated question that you don’t answer in one study,” said Dr. Myran, an assistant professor of family medicine at University of Ottawa.
“This contributes to the literature and to a sign, or signal, of concern.”
Dr. Myran’s previous research has found that patients with cannabis use disorder died at almost three times the rate of individuals without the disorder over a five-year period. He has also reported that more cases of schizophrenia and psychosis in Canada have been linked to cannabis use disorder since the drug was legalized.
The latest study, focusing on dementia, adds to a growing body of literature on regular or heavy cannabis use and cognition. Researchers have reported impacts on verbal learning, memory and attention, while imaging studies have pointed to changes in the brain related to the use of cannabis and other substances.
Veterans with traumatic brain injuries in addition to cannabis use disorder may be at heightened risk for early-onset dementia, researchers reported last year.
But many of the studies are relatively small. The new report’s strength was its large sample and the ability to track patients over time who did not have a diagnosis of dementia when they entered the study, said Madeline Meier, an associate professor of psychology at Arizona State University, who was not involved in the study.
“They were able to rule out dementia at the time of the first cannabis visit, and were able to show the temporal order — the cannabis came first, and the dementia came second,” said Dr. Meier.
Her research, which has followed and periodically tested a cohort of over 1,000 individuals over a period of many years, has linked cannabis use and neuropsychological decline.
“I think you want to combat this whole idea that cannabis is harmless and maybe even has some medical benefits,” Dr. Meier said. “This study is showing an association that I think people should take seriously and say, ‘Maybe this is putting me at risk.’”
She noted that the work by Dr. Myran and his colleagues also found that people seeking care for alcohol use were even more likely to receive a dementia diagnosis than were cannabis users.
“I’m worried about the substance abuse in that Baby Boomer age,” she said.
More and more people, including seniors, are using cannabis. Medical visits related to cannabis increased more than fivefold among adults 45 and older between 2008 and 2021, the new study found. Among adults 65 and over, visits increased almost 27-fold.
The study included more than 6 million people age 45 and over who did not have a diagnosis of dementia at the start of the research. Of them, 16,275 had an acute-care medical encounter because of cannabis.
The patients with cannabis-related visits were compared to the matched general population, and in a separate comparison, to 140,824 matched patients who needed medical care for all other reasons.
Within five years, 5 percent of those with acute care cannabis visits received a dementia diagnosis. The figure for individuals needing care for other reasons was 3.6 percent, and for similar individuals in the general population, 1.3 percent.
But people who are heavy cannabis users differ from those who are not in a variety of ways, some of which may help explain the increased risk for dementia, Dr. Myran explained.
While some of the factors can be accounted for, he said, “you can’t control for all of them.”
Another unknown is self-medication, he said. Someone who has started experiencing symptoms of cognitive decline may be more likely to turn to cannabis. If so, then “it looks as if the cannabis is causing dementia, but it’s just on the pathway — they were already developing dementia,” Dr. Myran said.
After making adjustments for age, sex, income and other factors, including other health conditions, he and his colleagues determined that patients who sought care for cannabis-related reasons were 1.23 times as likely as those who had gotten any kind of acute care to be diagnosed with dementia, and 1.72 times as likely as those in the healthier general population.
Science
California’s last nuclear plant clears major hurdle to power on
California environmental regulators on Thursday struck a landmark deal with Pacific Gas & Electric to extend the life of the state’s last remaining nuclear power plant in exchange for thousands of acres of new land conservation in San Luis Obispo County.
PG&E’s agreement with the California Coastal Commission is a key hurdle for the Diablo Canyon nuclear plant to remain online until at least 2030. The plant was slated to close this year, largely due to concerns over seismic safety, but state officials pushed to delay it — saying the plant remains essential for the reliable operation of California’s electrical grid. Diablo Canyon provides nearly 9% of the electricity generated in the state, making it the state’s single largest source.
The Coastal Commission voted 9-3 to approve the plan, settling the fate of some 12,000 acres that surround the power plant as a means of compensation for environmental harm caused by its continued operation.
Nuclear power does not emit greenhouse gases. But Diablo Canyon uses an estimated 2.5 billion gallons of ocean water each day to absorb heat in a process known as “once-through cooling,” which kills an estimated two billion or more marine organisms each year.
Some stakeholders in the region celebrated the conservation deal, while others were disappointed by the decision to trade land for marine impacts — including a Native tribe that had hoped the land would be returned to them. Diablo Canyon sits along one of the most rugged and ecologically rich stretches of the California coast.
Under the agreement, PG&E will immediately transfer a 4,500-acre parcel on the north side of the property known as the “North Ranch” into a conservation easement and pursue transfer of its ownership to a public agency such as the California Department of Parks and Recreation, a nonprofit land conservation organization or tribe. A purchase by State Parks would result in a more than 50% expansion of the existing Montaña de Oro State Park.
PG&E will also offer a 2,200-acre parcel on the southern part of the property known as “Wild Cherry Canyon” for purchase by a government agency, nonprofit land conservation organization or tribe. In addition, the utility will provide $10 million to plan and manage roughly 25 miles of new public access trails across the entire property.
“It’s going to be something that changes lives on the Central Coast in perpetuity,” Commissioner Christopher Lopez said at the meeting. “This matters to generations that have yet to exist on this planet … this is going to be a place that so many people mark in their minds as a place that transforms their lives as they visit and recreate and love it in a way most of us can’t even imagine today.”
Critically, the plan could see Diablo Canyon remain operational much longer than the five years dictated by Thursday’s agreement. While the state Legislature only authorized the plant to operate through 2030, PG&E’s federal license renewal would cover 20 years of operations, potentially keeping it online until 2045.
Should that happen, the utility would need to make additional land concessions, including expanding an existing conservation area on the southern part of the property known as the “South Ranch” to 2,500 acres. The plan also includes rights of first refusal for a government agency or a land conservation group to purchase the entirety of the South Ranch, 5,000 acres, along with Wild Cherry Canyon — after 2030.
Pelicans along the concrete breakwater at Pacific Gas and Electric’s Diablo Canyon Power Plant
(Brian van der Brug/Los Angeles Times)
Many stakeholders were frustrated by the carve-out for the South Ranch, but still saw the agreement as an overall victory for Californians.
“It is a once in a lifetime opportunity,” Sen. John Laird (D-Santa Cruz) said in a phone call ahead of Thursday’s vote. “I have not been out there where it has not been breathtakingly beautiful, where it is not this incredible, unique location, where you’re not seeing, for much of it, a human structure anywhere. It is just one of those last unique opportunities to protect very special land near the California coast.”
Others, however, described the deal as disappointing and inadequate.
That includes many of the region’s Native Americans who said they felt sidelined by the agreement. The deal does not preclude tribal groups from purchasing the land in the future, but it doesn’t guarantee that or give them priority.
The yak titʸu titʸu yak tiłhini Northern Chumash Tribe of San Luis Obispo County and Region, which met with the Coastal Commission several times in the lead-up to Thursday’s vote, had hoped to see the land returned to them.
Scott Lanthrop is a member of the tribe’s board and has worked on the issue for several years.
“The sad part is our group is not being recognized as the ultimate conservationist,” he told The Times. “Any normal person, if you ask the question, would you rather have a tribal group that is totally connected to earth and wind and water, or would you like to have some state agency or gigantic NGO manage this land, I think the answer would be, ‘Hey, you probably should give it back to the tribe.’”
Tribe chair Mona Tucker said she fears that free public access to the land could end up harming it instead of helping it, as the Coastal Commission intends.
“In my mind, I’m not understanding how taking the land … is mitigation for marine life,” Tucker said. “It doesn’t change anything as far as impacts to the water. It changes a lot as far as impacts to the land.”
Montaña de Oro State Park.
(Christopher Reynolds / Los Angeles Times)
The deal has been complicated by jurisdictional questions, including who can determine what happens to the land. While PG&E owns the North Ranch parcel that could be transferred to State Parks, the South Ranch and Wild Cherry Canyon are owned by its subsidiary, Eureka Energy Company.
What’s more, the California Public Utilities Commission, which regulates utilities such as PG&E, has a Tribal Land Transfer Policy that calls for investor-owned power companies to transfer land they no longer want to Native American tribes.
In the case of Diablo Canyon, the Coastal Commission became the decision maker because it has the job of compensating for environmental harm from the facility’s continued operation. Since the commission determined Diablo’s use of ocean water can’t be avoided, it looked at land conservation as the next best method.
This “out-of-kind” trade-off is a rare, but not unheard of way of making up for the loss of marine life. It’s an approach that is “feasible and more likely to succeed” than several other methods considered, according to the commission’s staff report.
“This plan supports the continued operation of a major source of reliable electricity for California, and is in alignment with our state’s clean energy goals and focus on coastal protection,” Paula Gerfen, Diablo Canyon’s senior vice president and chief nuclear officer, said in a statement.
But Assemblymember Dawn Addis (D-Morro Bay) said the deal was “not the best we can do” — particularly because the fate of the South Ranch now depends on the plant staying in operation beyond 2030.
“I believe the time really is now for the immediate full conservation of the 12,000 [acres], and to bring accountability and trust back for the voters of San Luis Obispo County,” Addis said during the meeting.
There are also concerns about the safety of continuing to operate a nuclear plant in California, with its radioactive waste stored in concrete casks on the site. Diablo Canyon is subject to ground shaking and earthquake hazards, including from the nearby Hosgri Fault and the Shorline Fault, about 2.5 miles and 1 mile from the facility, respectively.
PG&E says the plant has been built to withstand hazards. It completed a seismic hazard assessment in 2024, and determined Diablo Canyon is safe to continue operation through 2030. The Coastal Commission, however, found if the plant operates longer, it would warrant further seismic study.
A key development for continuing Diablo Canyon’s operation came in 2022 with Senate Bill 846, which delayed closure by up to five additional years. At the time, California was plagued by rolling blackouts driven extreme heat waves, and state officials were growing wary about taking such a major source of power offline.
But California has made great gains in the last several years — including massive investments in solar energy and battery storage — and some questioned whether the facility is still needed at all.
Others said conserving thousands of acres of land still won’t make up for the harms to the ocean.
“It is unmitigatable,” said David Weisman, executive director of the nonprofit Alliance for Nuclear Responsibility. He noted that the Coastal Commission’s staff report says it would take about 99 years to balance the loss of marine life with the benefits provided by 4,500 acres of land conservation. Twenty more years of operation would take about 305 years to strike that same balance.
But some pointed out that neither the commission nor fisheries data find Diablo’s operations cause declines in marine life. Ocean harm may be overestimated, said Seaver Wang, an oceanographer and the climate and energy director at the Breakthrough Institute, a Berkeley-based research center.
In California’s push to transition to clean energy, every option comes with downsides, Wang said. In the case of nuclear power — which produces no greenhouse gas emissions — it’s all part of the trade off, he said.
“There’s no such thing as impacts-free energy,” he said.
The Coastal Commission’s vote is one of the last remaining obstacles to keeping the plant online. PG&E will also need a final nod from the Regional Water Quality Control Board, which decides on a pollution discharge permit in February.
The federal Nuclear Regulatory Commission will also have to sign off on Diablo’s extension.
Science
In search for autism’s causes, look at genes, not vaccines, researchers say
Earlier this year, Health and Human Services Secretary Robert F. Kennedy Jr. pledged that the search for autism’s cause — a question that has kept researchers busy for the better part of six decades — would be over in just five months.
“By September, we will know what has caused the autism epidemic, and we’ll be able to eliminate those exposures,” Kennedy told President Trump during a Cabinet meeting in April.
That ambitious deadline has come and gone. But researchers and advocates say that Kennedy’s continued fixation on autism’s origins — and his frequent, inaccurate claims that childhood vaccines are somehow involved — is built on fundamental misunderstandings of the complex neurodevelopmental condition.
Even after more than half a century of research, no one yet knows exactly why some people have autistic traits and others do not, or why autism spectrum disorder looks so different across the people who have it. But a few key themes have emerged.
Researchers believe that autism is most likely the result of a complex set of interactions between genes and the environment that unfold while a child is in the womb. It can be passed down through families, or originate with a spontaneous gene mutation.
Environmental influences may indeed play a role in some autism cases, but their effect is heavily influenced by a person’s genes. There is no evidence for a single trigger that causes autism, and certainly not one a child encounters after birth: not a vaccine, a parenting style or a post-circumcision Tylenol.
“The real reason why it’s complicated, the more fundamental one, is that there’s not a single cause,” said Irva Hertz-Picciotto, a professor of public health science and director of the Environmental Health Sciences Center at UC Davis. “It’s not a single cause from one person to the next, and not a single cause within any one person.”
Kennedy, an attorney who has no medical or scientific training, has called research into autism’s genetics a “dead end.” Autism researchers counter that it’s the only logical place to start.
“If we know nothing else, we know that autism is primarily genetic,” said Joe Buxbaum, a molecular neuroscientist who directs the Seaver Autism Center for Research and Treatment at the Icahn School of Medicine at Mount Sinai. “And you don’t have to actually have the exact genes [identified] to know that something is genetic.”
Some neurodevelopment disorders arise from a difference in a single gene or chromosome. People with Down syndrome have an extra copy of chromosome 21, for example, and Fragile X syndrome results when the FMR1 gene isn’t expressed.
Autism in most cases is polygenetic, which means that multiple genes are involved, with each contributing a little bit to the overall picture.
Researchers have found hundreds of genes that could be associated with autism; there may be many more among the roughly 20,000 in the human genome.
In the meantime, the strongest evidence that autism is genetic comes from studies of twins and other sibling groups, Buxbaum and other researchers said.
The rate of autism in the U.S. general population is about 2.8%, according to a study published last year in the journal Pediatrics. Among children with at least one autistic sibling, it’s 20.2% — about seven times higher than the general population, the study found.
Twin studies reinforce the point. Both identical and fraternal twins develop in the same womb and are usually raised in similar circumstances in the same household. The difference is genetic: identical twins share 100% of their genetic information, while fraternal twins share about 50% (the same as nontwin siblings).
If one fraternal twin is autistic, the chance that the other twin is also autistic is about 20%, or about the same as it would be for a nontwin sibling.
But if one in a pair of identical twins is autistic, the chance that the other twin is also autistic is significantly higher. Studies have pegged the identical twin concurrence rate anywhere from 60% to 90%, though the intensity of the twins’ autistic traits may differ significantly.
Molecular genetic studies, which look at the genetic information shared between siblings and other blood relatives, have found similar rates of genetic influence on autism, said Dr. John Constantino, a professor of pediatrics, psychiatry and behavioral sciences at the Emory University School of Medicine and chief of behavioral and mental health at Children’s Healthcare of Atlanta.
Together, he said, “those studies have indicated that a vast share of the causation of autism can be traced to the effects of genetic influences. That is a fact.”
Buxbaum compares the heritability of autism to the heritability of height, another polygenic trait.
“There’s not one gene that’s making you taller or shorter,” Buxbaum said. Hundreds of genes play a role in where you land on the height distribution curve. A lot of those genes run in families — it’s not unusual for very tall people, for example, to have very tall relatives.
But parents pass on a random mix of their genes to their children, and height distribution across a group of same-sex siblings can vary widely. Genetic mutations can change the picture. Marfan syndrome, a condition caused by mutations in the FBN1 gene, typically makes people grow taller than average. Hundreds of genetic mutations are associated with dwarfism, which causes shorter stature.
Then once a child is born, external factors such as malnutrition or disease can affect the likelihood that they reach their full height potential.
So genes are important. But the environment — which in developmental science means pretty much anything that isn’t genetics, including parental age, nutrition, air pollution and viruses — can play a major role in how those genes are expressed.
“Genetics does not operate in a vacuum, and at the same time, the impact of the environment on people is going to depend on a person’s individual genetics,” said Brian K. Lee, a professor of epidemiology and biostatistics at Drexel University who studies the genetics of developmental disorders.
Unlike the childhood circumstances that can affect height, the environmental exposures associated with autism for the most part take place in utero.
Researchers have identified multiple factors linked to increased risks of the disorder, including older parental age, infant prematurity and parental exposure to air pollution and industrial solvents.
Investigations into some of these linkages were among the more than 50 autism-related studies whose funding Kennedy has cut since taking office, a ProPublica investigation found. In contrast, no credible study has found links between vaccines and autism — and there have been many.
One move from the Department of Health and Human Services has been met with cautious optimism: even as Kennedy slashed funding to other research projects, the department in September announced a $50-million initiative to explore the interactions of genes and environmental factors in autism, which has been divided among 13 different research groups at U.S. universities, including UCLA and UC San Diego.
The department’s selection of well-established, legitimate research teams was met with relief by many autism scientists.
But many say they fear that such decisions will be an anomaly under Kennedy, who has repeatedly rejected facts that don’t conform to his preferred hypotheses, elevated shoddy science and muddied public health messaging on autism with inaccurate information.
Disagreements are an essential part of scientific inquiry. But the productive ones take place in a universe of shared facts and build on established evidence.
And when determining how to spend limited resources, researchers say, making evidence-based decisions is vital.
“There are two aspects of these decisions: Is it a reasonable expenditure based on what we already know? And if you spend money here, will you be taking money away from HHS that people are in desperate need of?” Constantino said. “If you’re going to be spending money, you want to do that in a way that is not discarding what we already know.”
Science
Contributor: New mothers are tempted by Ozempic but don’t have the data they need
My friend Sara, eight weeks after giving birth, left me a tearful voicemail. I’m a clinical psychologist specializing in postpartum depression and psychosis, but mental health wasn’t Sara’s issue. Postpartum weight gain was.
Sara told me she needed help. She’d gained 40 pounds during her pregnancy, and she was still 25 pounds overweight. “I’m going back to work and I can’t look like this,” she said. “I need to take Ozempic or something. But do you know if it’s safe?”
Great question. Unfortunately researchers don’t yet have an answer. On Dec. 1, the World Health Organization released its first guidelines on the use of GLP-1 receptor agonists such as Ozempic, generically known as semaglutide. One of the notable policy suggestions in that report is to not prescribe GLP-1s to pregnant women. Disappointingly, the report says nothing about the use of the drug by postpartum women, including those who are breastfeeding.
There was a recent Danish study that led to medical guidelines against prescribing to patients who are pregnant or breastfeeding.
None of that is what my friend wanted to hear. I could only encourage her to speak to her own medical doctor.
Sara’s not alone. I’ve seen a trend emerging in my practice in which women use GLP-1s to shed postpartum weight. The warp speed “bounce-back” ideal of body shapes for new mothers has reemerged, despite the mental health field’s advocacy to abolish the archaic pressure of martyrdom in motherhood. GLP-1s are being sold and distributed by compound pharmacies like candy. And judging by their popularity, nothing tastes sweeter than skinny feels.
New motherhood can be a stressful time for bodies and minds, but nature has also set us up for incredible growth at that moment. Contrary to the myth of spaced-out “mommy brains,” new neuroplasticity research shows that maternal brains are rewired for immense creativity and problem solving.
How could GLP-1s affect that dynamic? We just don’t know. We do know that these drugs are associated with changes far beyond weight loss, potentially including psychiatric effects such as combating addiction.
Aside from physical effects, this points to an important unanswered research question: What effects, if any, do GLP-1s have on a woman’s brain as it is rewiring to attune to and take care of a newborn? And on a breastfeeding infant? If GLP-1s work on the pleasure center of the brain and your brain is rewiring to feel immense pleasure from a baby coo, I can’t help but wonder if that will be dampened. When a new mom wants a prescription for a GLP-1 to help shed baby weight, her medical provider should emphasize those unknowns.
These drugs may someday be a useful tool for new mothers. GLP-1s are helping many people with conditions other than obesity. A colleague of mine was born with high blood pressure and cholesterol. She exercised every day and adopted a pescatarian diet. Nothing budged until she added a GLP-1 to her regimen, bringing her blood pressure to a healthy 120/80 and getting cholesterol under control. My brother, an otherwise healthy young man recently diagnosed with a rare idiopathic lymphedema of his left leg, is considering GLP-1s to address inflammation and could be given another chance at improving his quality of life.
I hope that GLP-1s will continue to help those who need it. And I urge everyone — especially new moms — to proceed with caution. A healthy appetite for nutritious food is natural. That food fuels us for walks with our dogs, swims along a coastline, climbs through leafy woods. It models health and balance for the young ones who are watching us for clues about how to live a healthy life.
Nicole Amoyal Pensak, a clinical psychologist and researcher, is the author of “Rattled: How to Calm New Mom Anxiety With the Power of the Postpartum Brain.”
-
Alaska6 days agoHowling Mat-Su winds leave thousands without power
-
Politics1 week agoTrump rips Somali community as federal agents reportedly eye Minnesota enforcement sweep
-
Ohio1 week ago
Who do the Ohio State Buckeyes hire as the next offensive coordinator?
-
Texas6 days agoTexas Tech football vs BYU live updates, start time, TV channel for Big 12 title
-
News1 week agoTrump threatens strikes on any country he claims makes drugs for US
-
World1 week agoHonduras election council member accuses colleague of ‘intimidation’
-
Washington3 days agoLIVE UPDATES: Mudslide, road closures across Western Washington
-
Iowa5 days agoMatt Campbell reportedly bringing longtime Iowa State staffer to Penn State as 1st hire