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What to know about raw oysters and flesh-eating bacteria
Author of the article:Washington Post
Washington Post
Lindsey Bever
Published Sep 10, 2025 • 4 minute read
Join the conversation
raw oysters
Raw oysters
Is it true that raw oysters are dangerous?
Many raw dishes such as steak tartare and sushi carry a risk of illness.
But raw oysters “are among the riskiest foods that we consume regularly,” said Benjamin Chapman, the department head of agricultural and human sciences at North Carolina State University.
In recent months, multiple states have reported cases of a deadly flesh-eating form of a bacteria that, in rare cases, can be spread by raw oysters. Vibrio vulnificus – which is usually spread through open wounds in contaminated seawater, but in an estimated 10 percent of cases can come from eating raw or undercooked shellfish – has led to at least five deaths in Florida and four in Louisiana, state health officials said.
Oysters and other mollusks such as clams and mussels live in coastal waters that contain bacteria, viruses and other contaminants. Some oysters may carry these pathogens, including the bacterium Vibrio that causes an infection called vibriosis.
Both Vibrio parahaemolyticus and Vibrio vulnificus can cause nausea, vomiting, diarrhea and fever. But Vibrio vulnificus may enter the bloodstream, leading to septicemia or serious wound infections that sometimes result in amputations or death. An estimated 1 in 5 cases of Vibrio vulnificus infections are fatal, the CDC stated.
There are some 80,000 cases of vibriosis each year in the United States, and most people get vibriosis from eating raw or undercooked shellfish, particularly oysters, that have the bacteria, according to the Centers for Disease Control and Prevention.
Raw oysters also can spread viruses such as hepatitis A and norovirus, the notorious and highly contagious stomach bug.
The Food and Drug Administration requires seafood processors, including oyster processors, to follow Seafood Hazard Analysis and Critical Control Point regulations. They mandate that processors identify and control hazards. Additionally, under the federal-state National Shellfish Sanitation Program, oyster beds are routinely tested, and only certified suppliers can harvest, handle and store oysters from approved waters.
State and local agencies regulate restaurants where oysters are sold, experts said.
But it is not possible to test every oyster, and there is no way to tell by sight, smell or taste whether an oyster is carrying disease or whether a person will get sick from it, experts said.
Moreover, season and other factors are not reliable predictors. While Vibrio vulnificus, for instance, is more common in coastal waters during warmer months, the adage that people should eat raw oysters only in months that end in R – or cold-weather months in North America – is “a myth” as oysters may be harvested and imported from warmer waters, Chapman said.
“It’s not fail-safe because we import oysters from all over the place,” he said. “Raw oysters are a risky food regardless of the time of year.” Because of climate change-related increases in coastal water temperatures, Vibrio is becoming more common. (People can also get infected by swallowing water or through an open wound while swimming in a contaminated area.)
The most reliable way to eliminate pathogens is to cook the oysters. Many recipes call for steamed, grilled or roasted oysters, oftentimes cooking them in butter, herbs or seasonings. “Cooking will inactivate these harmful microorganisms very readily,” said Keith Schneider, a professor in food science and human nutrition at the University of Florida.
People who want to consume them raw may consider oysters that have undergone high-pressure processing in which the oysters are exposed to cold water and high pressure to help reduce Vibrio while keeping the raw texture, said Razieh Farzad, an assistant professor and a seafood safety extension specialist at the University of Florida. But, she said, only some processors use the technology, and that information may not be easily accessible for consumers.
Many experts suggest that people who are at higher risk, including older people and those who are immunocompromised, have liver disease, diabetes or are pregnant, should consider avoiding raw oysters. But experts are not necessarily against the delicacy for those who are not at increased risk.
“As long as people have the information and they are aware of the risks with choices they’re making, I think that’s a good place for us to be,” Chapman said.
What else you should know
Oysters are rich in essential micronutrients, including copper, iron, vitamin B12, and contain more zinc per serving than any other food, said Alison Kane, a registered dietitian at Massachusetts General Hospital.
While most minerals are retained during the cooking process, some nutrients may be lost at high temperatures, particularly when frying, which also adds extra calories and fat from the oils or batter, she said.
But grilling and steaming “are gentler cooking methods that don’t introduce additional fats or sodium and retain most of oysters’ nutrient density,” Kane added.
The bottom line: While many people enjoy raw oysters, the mollusks carry higher risks than many other foods and should be avoided by those who are more susceptible to potential infection. There are methods for mitigating risk,, but the most reliable way to kill pathogens is to cook the oysters.
torontosun.com
Author of the article:Washington Post
Washington Post
Lindsey Bever
Published Sep 10, 2025 • 4 minute read
Join the conversation
raw oysters
Raw oysters
Is it true that raw oysters are dangerous?
Many raw dishes such as steak tartare and sushi carry a risk of illness.
But raw oysters “are among the riskiest foods that we consume regularly,” said Benjamin Chapman, the department head of agricultural and human sciences at North Carolina State University.
In recent months, multiple states have reported cases of a deadly flesh-eating form of a bacteria that, in rare cases, can be spread by raw oysters. Vibrio vulnificus – which is usually spread through open wounds in contaminated seawater, but in an estimated 10 percent of cases can come from eating raw or undercooked shellfish – has led to at least five deaths in Florida and four in Louisiana, state health officials said.
Oysters and other mollusks such as clams and mussels live in coastal waters that contain bacteria, viruses and other contaminants. Some oysters may carry these pathogens, including the bacterium Vibrio that causes an infection called vibriosis.
Both Vibrio parahaemolyticus and Vibrio vulnificus can cause nausea, vomiting, diarrhea and fever. But Vibrio vulnificus may enter the bloodstream, leading to septicemia or serious wound infections that sometimes result in amputations or death. An estimated 1 in 5 cases of Vibrio vulnificus infections are fatal, the CDC stated.
There are some 80,000 cases of vibriosis each year in the United States, and most people get vibriosis from eating raw or undercooked shellfish, particularly oysters, that have the bacteria, according to the Centers for Disease Control and Prevention.
Raw oysters also can spread viruses such as hepatitis A and norovirus, the notorious and highly contagious stomach bug.
The Food and Drug Administration requires seafood processors, including oyster processors, to follow Seafood Hazard Analysis and Critical Control Point regulations. They mandate that processors identify and control hazards. Additionally, under the federal-state National Shellfish Sanitation Program, oyster beds are routinely tested, and only certified suppliers can harvest, handle and store oysters from approved waters.
State and local agencies regulate restaurants where oysters are sold, experts said.
But it is not possible to test every oyster, and there is no way to tell by sight, smell or taste whether an oyster is carrying disease or whether a person will get sick from it, experts said.
Moreover, season and other factors are not reliable predictors. While Vibrio vulnificus, for instance, is more common in coastal waters during warmer months, the adage that people should eat raw oysters only in months that end in R – or cold-weather months in North America – is “a myth” as oysters may be harvested and imported from warmer waters, Chapman said.
“It’s not fail-safe because we import oysters from all over the place,” he said. “Raw oysters are a risky food regardless of the time of year.” Because of climate change-related increases in coastal water temperatures, Vibrio is becoming more common. (People can also get infected by swallowing water or through an open wound while swimming in a contaminated area.)
The most reliable way to eliminate pathogens is to cook the oysters. Many recipes call for steamed, grilled or roasted oysters, oftentimes cooking them in butter, herbs or seasonings. “Cooking will inactivate these harmful microorganisms very readily,” said Keith Schneider, a professor in food science and human nutrition at the University of Florida.
People who want to consume them raw may consider oysters that have undergone high-pressure processing in which the oysters are exposed to cold water and high pressure to help reduce Vibrio while keeping the raw texture, said Razieh Farzad, an assistant professor and a seafood safety extension specialist at the University of Florida. But, she said, only some processors use the technology, and that information may not be easily accessible for consumers.
Many experts suggest that people who are at higher risk, including older people and those who are immunocompromised, have liver disease, diabetes or are pregnant, should consider avoiding raw oysters. But experts are not necessarily against the delicacy for those who are not at increased risk.
“As long as people have the information and they are aware of the risks with choices they’re making, I think that’s a good place for us to be,” Chapman said.
What else you should know
Oysters are rich in essential micronutrients, including copper, iron, vitamin B12, and contain more zinc per serving than any other food, said Alison Kane, a registered dietitian at Massachusetts General Hospital.
While most minerals are retained during the cooking process, some nutrients may be lost at high temperatures, particularly when frying, which also adds extra calories and fat from the oils or batter, she said.
But grilling and steaming “are gentler cooking methods that don’t introduce additional fats or sodium and retain most of oysters’ nutrient density,” Kane added.
The bottom line: While many people enjoy raw oysters, the mollusks carry higher risks than many other foods and should be avoided by those who are more susceptible to potential infection. There are methods for mitigating risk,, but the most reliable way to kill pathogens is to cook the oysters.
What to know about raw oysters and flesh-eating bacteria
Is it true that raw oysters are dangerous?
Oldest known lizard ancestor discovered in England
Author of the article:AFP
AFP
Published Sep 10, 2025 • Last updated 1 day ago • 2 minute read
New Zealand's tuatara reptile, which bears some striking similarities to the lizard ancestor discovered in England. Photo by Marty MELVILLE /POOL/AFP/File
Paris (AFP) — Scientists announced Wednesday they have discovered the oldest-known member of the lizard family in southwest England, a tiny creature that used its surprisingly large teeth to hunt cockroaches 242 million years ago.
The ancient reptile, which lived during the Middle Triassic epoch shortly before the rise of the dinosaurs, was so small its entire body could fit in the palm of a human hand.
“The new animal is unlike anything yet discovered and has made us all think again about the evolution of the lizard, snakes and the tuatara,” the latter of which is a New Zealand reptile, Dan Marke of the University of Bristol said in a statement.
The skeleton of the oldest known member of the lepidosauria order, a family of reptiles, was found at a fossil-rich beach in Devon, southwest England, in 2015.
But figuring out what it actually was took the scientists years, and the discovery was announced in a study in the journal Nature on Wednesday.
“The new fossil shows almost none of what we expected,” said Marke, the study’s lead author.
Modern lizards and snakes have a partially hinged skull and plenty of teeth on the roof of their mouth — but this ancient ancestor had neither.
“Not only this but it possesses some spectacularly large teeth compared to its closest relatives,” the palaeobiologist said.
It also has a bone running from cheek to jaw, a feature it shares only with the unique tuatara that is often referred to as a “living fossil”.
“The new beast” used these teeth “to pierce and shear the hard cuticles of its insect prey, pretty much as the tuatara does today,” said study co-author Michael Benton, also from Bristol University.
The fossil was difficult to study because it is so small — the skull is just 1.5 centimetres (0.6 of an inch) wide — and was preserved in a large rock.
So the British researchers scanned it using the European Synchrotron Radiation Facility, which works as a kind of huge microscope producing X-rays 100 billion times brighter than those used in hospitals.
The Synchrotron allowed the scientists to “zoom in on large objects and obtain very high-resolution images,” said Vincent Fernandez, a palaeontologist at the facility in France.
The scientists named the lizard ancestor Agriodontosaurus helsbypetrae, after the Helsby Sandstone Formation where it was discovered.
torontosun.com
Author of the article:AFP
AFP
Published Sep 10, 2025 • Last updated 1 day ago • 2 minute read
New Zealand's tuatara reptile, which bears some striking similarities to the lizard ancestor discovered in England. Photo by Marty MELVILLE /POOL/AFP/File
Paris (AFP) — Scientists announced Wednesday they have discovered the oldest-known member of the lizard family in southwest England, a tiny creature that used its surprisingly large teeth to hunt cockroaches 242 million years ago.
The ancient reptile, which lived during the Middle Triassic epoch shortly before the rise of the dinosaurs, was so small its entire body could fit in the palm of a human hand.
“The new animal is unlike anything yet discovered and has made us all think again about the evolution of the lizard, snakes and the tuatara,” the latter of which is a New Zealand reptile, Dan Marke of the University of Bristol said in a statement.
The skeleton of the oldest known member of the lepidosauria order, a family of reptiles, was found at a fossil-rich beach in Devon, southwest England, in 2015.
But figuring out what it actually was took the scientists years, and the discovery was announced in a study in the journal Nature on Wednesday.
“The new fossil shows almost none of what we expected,” said Marke, the study’s lead author.
Modern lizards and snakes have a partially hinged skull and plenty of teeth on the roof of their mouth — but this ancient ancestor had neither.
“Not only this but it possesses some spectacularly large teeth compared to its closest relatives,” the palaeobiologist said.
It also has a bone running from cheek to jaw, a feature it shares only with the unique tuatara that is often referred to as a “living fossil”.
“The new beast” used these teeth “to pierce and shear the hard cuticles of its insect prey, pretty much as the tuatara does today,” said study co-author Michael Benton, also from Bristol University.
The fossil was difficult to study because it is so small — the skull is just 1.5 centimetres (0.6 of an inch) wide — and was preserved in a large rock.
So the British researchers scanned it using the European Synchrotron Radiation Facility, which works as a kind of huge microscope producing X-rays 100 billion times brighter than those used in hospitals.
The Synchrotron allowed the scientists to “zoom in on large objects and obtain very high-resolution images,” said Vincent Fernandez, a palaeontologist at the facility in France.
The scientists named the lizard ancestor Agriodontosaurus helsbypetrae, after the Helsby Sandstone Formation where it was discovered.
Oldest known lizard ancestor discovered in England
The ancient reptile was so small its entire body could fit in the palm of a human hand.
For a lizard to survive 242 Million years of "Climate Change" in England is absolutely remarkable.
What is the ‘kissing bug’ disease now endemic in U.S.?
More than 100 million people are considered at risk of being infected with Chagas disease worldwide
Author of the article:Washington Post
Washington Post
Grace Moon
Published Sep 11, 2025 • Last updated 1 day ago • 3 minute read
Chagas disease
Eastern Bloodsucking Conenose Kissing Bug (Triatoma sanguisuga) on a leaf in Houston, TX. The dangerous biting insect native to the USA, carries Chagas disease. Photo by Getty Images
“Kissing bug” disease, also known as Chagas disease, is now considered an endemic illness in the United States, according to research in an infectious-disease journal published by the Centers for Disease Control and Prevention this month.
A disease is usually considered endemic when it is constantly present within a specific area or population. Worldwide, more than 100 million people are considered at risk of being infected with Chagas disease, according to the World Health Organization.
Here’s what to know.
– – –
What’s ‘kissing bug’ disease?
Chagas disease is caused by the parasite Trypanosoma cruzi, which is found in the feces of the triatomine bug – commonly known as the “kissing bug” because it often bites people’s faces. The insects become infected when they feed on the blood of hosts carrying the parasite.
The disease can spread to humans and animals in several ways, such as when contaminated feces are accidentally rubbed into open wounds, the eyes or the mouth.
The disease can also be transmitted congenitally, from mother to child, or through contaminated blood transfusions, though these types of transmission are rarer.
Several animals, including dogs, can host the parasite, and there has been growing evidence of local canine infections in states such as Texas and California.
– – –
What are the signs and symptoms?
Chagas disease has two phases: acute and chronic. The acute phase, which occurs in the first few weeks or months after infection, can be asymptomatic. It can also cause mild symptoms such as fever, fatigue, body aches or swelling of the eyelid. Seeking treatment at this stage is very important, according to the CDC.
In the absence of treatment, chronic Chagas disease can develop and last for several years or even a lifetime. As many as 30 percent of those with Chagas disease can develop serious health complications that can lead to conditions such as heart failure or an enlarged esophagus or colon, the CDC says. Others may remain asymptomatic.
The disease is “often fatal by the time symptoms develop,” said Paula Stigler Granados, an associate professor at the San Diego State University School of Public Health.
Doctors are able to test humans and pets for the disease using a variety of methods.
– – –
Where in the U.S. is Chagas disease spreading?
Non-imported cases of Chagas disease have been identified in at least eight U.S. states so far, the new research says: California, Arizona, Texas, Tennessee, Louisiana, Missouri, Mississippi and Arkansas.
Peter Hotez, dean of the National School of Tropical Medicine at the Baylor College of Medicine, said that there has long been a misconception about where the disease can spread.
“We always think of this as a problem purely affecting low and middle-income countries,” he said. “But in fact, there’s quite a high percentage of these illnesses in wealthy countries like the U.S.”
The bloodsucking insects “occur naturally in the southern half of the country and have been identified in 32 states,” according to the new research. Kissing bugs are otherwise often found in rural parts of Mexico, Central America and South America.
– – –
How is Chagas disease treated?
There are currently no vaccines or drugs to prevent Chagas disease, according to the CDC. In the U.S., two antiparasitic medicines have been approved by the U.S. Food and Drug Administration for those who are suspected to have been infected.
When traveling to countries where the disease is present, the CDC recommends reducing the risk of contact with infected kissing bugs, which are sometimes found in the cracks and crevices of poorly constructed houses and can survive both indoors and outdoors.
“We don’t have sufficient levels of active surveillance to look for these diseases,” Hotez said. “If you don’t look, you don’t find – and that’s been a big problem.”
While recognizing the disease as endemic is a “great first step,” Granados said, “labeling it as endemic will not change the fact that we don’t have systematic surveillance or the resources to support it.”
The CDC also recommends spraying areas with long-lasting insecticides, wearing clothing that covers the skin, and avoiding raw vegetables and unpeeled fruits in areas where Chagas disease has been detected. Pet owners can help prevent Chagas disease from reaching their furry friends by using anti-flea and tick medications such as Nexgard and Bravecto.
![GettyImages-1689262788[1].jpg](https://forums.canadiancontent.net/data/attachments/29/29312-40672eb4b6bcca37ee818f05da483c10.jpg "GettyImages-1689262788[1].jpg")
torontosun.com
More than 100 million people are considered at risk of being infected with Chagas disease worldwide
Author of the article:Washington Post
Washington Post
Grace Moon
Published Sep 11, 2025 • Last updated 1 day ago • 3 minute read
Chagas disease
Eastern Bloodsucking Conenose Kissing Bug (Triatoma sanguisuga) on a leaf in Houston, TX. The dangerous biting insect native to the USA, carries Chagas disease. Photo by Getty Images
“Kissing bug” disease, also known as Chagas disease, is now considered an endemic illness in the United States, according to research in an infectious-disease journal published by the Centers for Disease Control and Prevention this month.
A disease is usually considered endemic when it is constantly present within a specific area or population. Worldwide, more than 100 million people are considered at risk of being infected with Chagas disease, according to the World Health Organization.
Here’s what to know.
– – –
What’s ‘kissing bug’ disease?
Chagas disease is caused by the parasite Trypanosoma cruzi, which is found in the feces of the triatomine bug – commonly known as the “kissing bug” because it often bites people’s faces. The insects become infected when they feed on the blood of hosts carrying the parasite.
The disease can spread to humans and animals in several ways, such as when contaminated feces are accidentally rubbed into open wounds, the eyes or the mouth.
The disease can also be transmitted congenitally, from mother to child, or through contaminated blood transfusions, though these types of transmission are rarer.
Several animals, including dogs, can host the parasite, and there has been growing evidence of local canine infections in states such as Texas and California.
– – –
What are the signs and symptoms?
Chagas disease has two phases: acute and chronic. The acute phase, which occurs in the first few weeks or months after infection, can be asymptomatic. It can also cause mild symptoms such as fever, fatigue, body aches or swelling of the eyelid. Seeking treatment at this stage is very important, according to the CDC.
In the absence of treatment, chronic Chagas disease can develop and last for several years or even a lifetime. As many as 30 percent of those with Chagas disease can develop serious health complications that can lead to conditions such as heart failure or an enlarged esophagus or colon, the CDC says. Others may remain asymptomatic.
The disease is “often fatal by the time symptoms develop,” said Paula Stigler Granados, an associate professor at the San Diego State University School of Public Health.
Doctors are able to test humans and pets for the disease using a variety of methods.
– – –
Where in the U.S. is Chagas disease spreading?
Non-imported cases of Chagas disease have been identified in at least eight U.S. states so far, the new research says: California, Arizona, Texas, Tennessee, Louisiana, Missouri, Mississippi and Arkansas.
Peter Hotez, dean of the National School of Tropical Medicine at the Baylor College of Medicine, said that there has long been a misconception about where the disease can spread.
“We always think of this as a problem purely affecting low and middle-income countries,” he said. “But in fact, there’s quite a high percentage of these illnesses in wealthy countries like the U.S.”
The bloodsucking insects “occur naturally in the southern half of the country and have been identified in 32 states,” according to the new research. Kissing bugs are otherwise often found in rural parts of Mexico, Central America and South America.
– – –
How is Chagas disease treated?
There are currently no vaccines or drugs to prevent Chagas disease, according to the CDC. In the U.S., two antiparasitic medicines have been approved by the U.S. Food and Drug Administration for those who are suspected to have been infected.
When traveling to countries where the disease is present, the CDC recommends reducing the risk of contact with infected kissing bugs, which are sometimes found in the cracks and crevices of poorly constructed houses and can survive both indoors and outdoors.
“We don’t have sufficient levels of active surveillance to look for these diseases,” Hotez said. “If you don’t look, you don’t find – and that’s been a big problem.”
While recognizing the disease as endemic is a “great first step,” Granados said, “labeling it as endemic will not change the fact that we don’t have systematic surveillance or the resources to support it.”
The CDC also recommends spraying areas with long-lasting insecticides, wearing clothing that covers the skin, and avoiding raw vegetables and unpeeled fruits in areas where Chagas disease has been detected. Pet owners can help prevent Chagas disease from reaching their furry friends by using anti-flea and tick medications such as Nexgard and Bravecto.
What is the ‘kissing bug’ disease now endemic in U.S.?
Worldwide, more than 100 million people are considered at risk of being infected with Chagas disease
Chronically sleepless? Study suggests it might cause your brain to age
Those with chronic insomnia are aging the equivalent of 3.5 additional years
Author of the article:Washington Post
Washington Post
Ariana Eunjung Cha
Published Sep 11, 2025 • 2 minute read
Persistent sleeplessness may be far worse than a passing annoyance – gradually unravelling memory and mental sharpness, according to new research.
A study published Wednesday in Neurology, the journal of the American Academy of Neurology, identifies a troubling link: Older people who have chronic insomnia appear more likely to experience accelerated aging of the brain. These changes are revealed in both cognitive tests and imaging scans showing the altered structure of the brain.
The research involved 2,750 cognitively healthy adults with an average age of 70. The participants, who were tracked on average for 5.6 years, underwent annual testing of executive functioning, visual-spatial reasoning and other dimensions of cognition.
The data showed that 14 percent of those with chronic insomnia developed mild cognitive impairment or dementia while 10 percent of those who did not have chronic insomnia did.
Researchers say that difference is significant in a study of this kind. Those with chronic insomnia are aging the equivalent of 3.5 additional years, a finding based on average cognitive performance and brain biomarkers expected for different age groups.
Diego Z. Carvalho, a sleep medicine specialist at the Mayo Clinic and lead author of the study, said the work supports growing evidence that suboptimal sleep, as early as in midlife, may foreshadow neurodegeneration. He noted that the study shows only an association and not causation.
“It could also be that poor sleep early on can be an indicator of cognitive decline,” Carvalho said. “It’s very hard to untangle.”
Santiago Clocchiatti-Tuozzo, a neurology resident at Yale New Haven Hospital who studies sleep and brain health, said one key finding in the study was that people with insomnia who slept fewer hours had worse outcomes, including poorer cognitive performance and more brain changes.
“If confirmed in future studies, these results could help shape strategies to preserve long-term brain health by considering not just sleep quality, but also how long people sleep,” said Clocchiatti-Tuozzo, who was not involved in the study.
Research on sleep and brain health has surged in the past decade, revealing important links between poor sleep and conditions such as dementia and Alzheimer’s. A landmark 2021 study published in JAMA Neurology found that sleeping more or less than the ideal range of seven to eight hours was connected to cognitive difficulties.
Sleeping less than six hours or more than nine hours was also tied to other health issues, including higher body mass index and increased symptoms of depression.
Karin G. Johnson, a sleep neurologist in Springfield, Massachusetts, said this type of detailed finding is fairly new for her field.
Adequate rest is crucial, Johnson said, because the brain’s process of clearing out toxins is thought to follow circadian rhythms and works best during sleep.
Johnson, an American Academy of Neurology fellow who was not involved in the study, hopes increased sleep among younger generations could lead to a healthier population in the future. She also advocates for policy changes, such as later school start times, to support better sleep habits.
“It’s important to lay that foundation of giving people enough time to sleep,” she said.
torontosun.com
Those with chronic insomnia are aging the equivalent of 3.5 additional years
Author of the article:Washington Post
Washington Post
Ariana Eunjung Cha
Published Sep 11, 2025 • 2 minute read
Persistent sleeplessness may be far worse than a passing annoyance – gradually unravelling memory and mental sharpness, according to new research.
A study published Wednesday in Neurology, the journal of the American Academy of Neurology, identifies a troubling link: Older people who have chronic insomnia appear more likely to experience accelerated aging of the brain. These changes are revealed in both cognitive tests and imaging scans showing the altered structure of the brain.
The research involved 2,750 cognitively healthy adults with an average age of 70. The participants, who were tracked on average for 5.6 years, underwent annual testing of executive functioning, visual-spatial reasoning and other dimensions of cognition.
The data showed that 14 percent of those with chronic insomnia developed mild cognitive impairment or dementia while 10 percent of those who did not have chronic insomnia did.
Researchers say that difference is significant in a study of this kind. Those with chronic insomnia are aging the equivalent of 3.5 additional years, a finding based on average cognitive performance and brain biomarkers expected for different age groups.
Diego Z. Carvalho, a sleep medicine specialist at the Mayo Clinic and lead author of the study, said the work supports growing evidence that suboptimal sleep, as early as in midlife, may foreshadow neurodegeneration. He noted that the study shows only an association and not causation.
“It could also be that poor sleep early on can be an indicator of cognitive decline,” Carvalho said. “It’s very hard to untangle.”
Santiago Clocchiatti-Tuozzo, a neurology resident at Yale New Haven Hospital who studies sleep and brain health, said one key finding in the study was that people with insomnia who slept fewer hours had worse outcomes, including poorer cognitive performance and more brain changes.
“If confirmed in future studies, these results could help shape strategies to preserve long-term brain health by considering not just sleep quality, but also how long people sleep,” said Clocchiatti-Tuozzo, who was not involved in the study.
Research on sleep and brain health has surged in the past decade, revealing important links between poor sleep and conditions such as dementia and Alzheimer’s. A landmark 2021 study published in JAMA Neurology found that sleeping more or less than the ideal range of seven to eight hours was connected to cognitive difficulties.
Sleeping less than six hours or more than nine hours was also tied to other health issues, including higher body mass index and increased symptoms of depression.
Karin G. Johnson, a sleep neurologist in Springfield, Massachusetts, said this type of detailed finding is fairly new for her field.
Adequate rest is crucial, Johnson said, because the brain’s process of clearing out toxins is thought to follow circadian rhythms and works best during sleep.
Johnson, an American Academy of Neurology fellow who was not involved in the study, hopes increased sleep among younger generations could lead to a healthier population in the future. She also advocates for policy changes, such as later school start times, to support better sleep habits.
“It’s important to lay that foundation of giving people enough time to sleep,” she said.
Chronically sleepless? Study suggests it might cause your brain to age
Persistent sleeplessness may be far worse than a passing annoyance - gradually unravelling memory and mental sharpness