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Science

A 319-million-year-old brain has been discovered. It could be the oldest of its kind

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CNN
 — 

A scan of the skull of a 319-million-year-old fossilized fish has led to the discovery of the oldest example of a well-preserved vertebrate brain, shining a new light on the early evolution of bony fish.

The fossil of the skull belonging to the extinct Coccocephalus wildi was found in a coal mine in England more than a century ago, according to researchers of the study published in the journal Nature on Wednesday.

The fossil is the only known specimen of the fish species so scientists from the University of Michigan in the US and the University of Birmingham in the UK used the nondestructive imaging technique of computed tomography (CT) scanning to look inside its skull and examine its internal bodily structure.

Upon doing so, came a surprise. The CT image showed an “unidentified blob,” a University of Michigan press release said.

The distinct, 3D object had a clearly defined structure with features found in vertebrate brains: It was bilaterally symmetrical, contained hollow spaces similar in appearance to ventricles and had extending filaments that resembled cranial nerves.

“This is such an exciting and unanticipated find,” study coauthor Sam Giles, a vertebrate paleontologist and senior research fellow at the University of Birmingham, told CNN Thursday, adding that they had “no idea” there was a brain inside when they decided to study the skull.

“It was so unexpected that it took us a while to be certain that it actually was a brain. Aside from being just a preservational curiosity, the anatomy of the brain in this fossil has big implications for our understanding of brain evolution in fishes,” she added.

C. wildi was an early ray-finned fish – possessing a backbone and fins supported by bony rods called “rays” – that is thought to have been 6 to 8 inches long, swum in an estuary, and ate small aquatic animals and aquatic insects, according to the researchers.

The brains of living ray-finned fish display structural features not seen in other vertebrates, most notably a forebrain consisting of neural tissue that folds outward, according to the study. In other vertebrates, this neural tissue folds inward.

C. wildi lacks this hallmark feature of ray-finned fish, with the configuration of a part of its forebrain called the “telencephalon” more closely resembling that of other vertebrates, such as amphibians, birds, reptiles and mammals, according to the study authors.

“This indicates that the telencephalon configuration seen in living ray-finned fishes must have emerged much later than previously thought,” lead study author Rodrigo Tinoco Figueroa, a doctoral student at the University of Michigan’s Museum of Paleontology, said.

He added that “our knowledge on the evolution of the vertebrate brain is mostly restricted to what we know from living species,” but “this fossil helps us fill important gaps in the knowledge, that could only be obtained from exceptional fossils like this.”

Unlike hard bones and teeth, scientists rarely find brain tissue – which is soft – preserved in vertebrate fossils, according to the researchers.

However, the study noted that C. wildi’s brain was “exceptionally” well preserved. While there are invertebrate brains up to 500 million years old that have been found, they are all flattened, said Giles, who added that this vertebrate brain is “the oldest three-dimensional fossil brain of anything we know.”

The skull was found in layers of soapstone. Low oxygen concentration, rapid burial by fine-grained sediment, and a very compact and protective braincase played key roles in preserving the brain of the fish, according to Figueroa.

The braincase created a chemical micro-environment around the enclosed brain that could have helped to replace its soft tissue with dense mineral that maintained the fine details of the brain’s 3D structures.

Giles said: “The next steps are to figure out exactly how such delicate features as the brain can be preserved for hundreds of millions of years, and look for more fossils that also preserve the brain.”

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Health

Complications during pregnancy linked to a higher risk of heart disease, study finds

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CNN
 — 

Five major pregnancy complications are strong lifelong risk factors for ischemic heart disease, a new study finds, with the greatest risk coming in the decade after delivery.

Ischemic heart disease refers to heart problems, including heart attack, caused by narrowed or dysfunctional blood vessels that reduce blood and oxygen flow to the heart.

Gestational diabetes and preeclampsia increased the risk of ischemic heart disease in the study by 54% and 30%, respectively, while other high blood pressure disorders during pregnancy doubled the risk. Delivering a baby early – before 37 weeks – or delivering a baby with a low birth weight were associated with a 72% and 10% increased risk, respectively.

The study, published in Wednesday in the BMJ, followed a cohort of more than 2 million women in Sweden with no history of heart disease who gave birth to single live infants between 1973 and 2015.

Roughly 30% of the women had at least one adverse pregnancy outcome. Those who had multiple adverse outcomes – whether in the same or different pregnancies – showed further increased risk of ischemic heart disease.

“These pregnancy outcomes are early signals for future risk of heart disease and can help identify high-risk women earlier and enable earlier interventions to improve their long-term outcomes and help prevent the development of heart disease in these women,” said Dr. Casey Crump, an author of the study and professor of family medicine at the Icahn School of Medicine at Mount Sinai.

Heart disease is the leading cause of death among women in the United States and accounts for 1 in 5 female deaths, according to the US Centers for Disease Control and Prevention. This research adds to mounting evidence that pregnancy provides important information about a woman’s cardiovascular health.

“What happens to a woman during pregnancy is almost like a stress test or a marker for her future cardiovascular risk after pregnancy. And unfortunately, a lot of women don’t get told this by anybody,” said CNN Medical Correspondent Dr. Tara Narula, an associate professor of cardiology and the associate director of the Women’s Heart Program at Lenox Hill Hospital. She was not involved in the new study.

Although it’s not completely clear why, experts say the normal changes that occur during pregnancy may unmask underlying health issues in some women with certain risk factors.

Experiencing an adverse pregnancy outcome – even temporarily – could result in changes to blood vessels and the heart that may persist or progress after delivery, increasing a woman’s risk for cardiovascular disease.

This heightened risk is a particular concern for women in the US, experts say, where the maternal mortality rate is several times higher than in other high-income countries.

“There’s been a change in the birthing population. US women are getting pregnant at a later age, and they have already accrued maybe one or two cardiovascular risk factors. Perhaps there are other stressors in life – depression, stress, isolation, obesity – lots of different things that are impacting women in the US,” said Dr. Garima Sharma, associate professor of cardiology and director of the Cardio-Obstetrics Program at Johns Hopkins University School of Medicine, who also was not involved in the new study.

Pregnancy complications are carefully monitored during pregnancy, but there is little evaluation of and education about the effects on cardiovascular health after delivery for women, experts say.

“And so they have their delivery, they’ve had maybe preeclampsia or gestational diabetes, and nobody really follows up with them. They are not told that, in fact, they are at increased risk,” Narula said.

Gestational diabetes is a marker not only for increased risk of diabetes but also for general cardiovascular disease. Preeclampsia and eclampsia are markers for hypertension risk as well as general cardiovascular risks.

Narula, a cardiologist who specializes in caring for women, regularly considers adverse pregnancy outcomes when evaluating patients and emphasizes the continued need for this.

“The classic risk calculator that we use doesn’t have anything in there for pregnancy complications, but you know, it should for women, and hopefully someday, they will start to take that into account,” she said.

The American Heart Association recommends that all health care professionals take a detailed history of pregnancy complications when assessing a woman’s heart disease risk, but this is not consistently done in clinical practice, especially in primary care, where most women are seen, Crump says.

“Raising awareness of these findings among physicians as well as women hopefully will enable more of these women to be screened early and hopefully improve their long-term outcomes,” he said.

Roughly 1 in 3 women will have an adverse pregnancy outcome. Experts say that improving your health before getting pregnant can help avoid these issues.

“Reducing your risk should start preconception, and so getting your body and yourself into the healthiest state possible before you ever even get pregnant is really the first step,” Narula said.

This includes achieving and maintaining a healthy body weight with a good diet and regular exercise, controlling high blood pressure and diabetes, quitting smoking and managing stress.

Taking action after pregnancy is equally important, as research has estimated that only 30% to 80% of women have a postpartum checkup 6 to 8 weeks after delivery.

“Making sure that these women actually are appropriately followed after their delivery and that there is a warm handoff between [obstetrics] and [maternal-fetal medicine] to their primary care doctors or preventive cardiologists who can then talk about optimizing cardiovascular risks and reduction of these risk factors post-pregnancy in the postpartum time frame is crucial,” Sharma said.

Experts hope that increased patient and provider awareness of the connection between pregnancy and heart health will keep birth from being a cause of death.

“Cardiovascular disease is preventable. It’s a leading cause of maternal mortality, but it doesn’t have to be. If we do a better job at screening patients before they get pregnant, if we do a better job of treating them during pregnancy and postpartum, we can improve women’s outcomes,” Narula said. “It’s a tragedy to bring a new life into the world, and then the mother suffers some horrible complication and/or death that could have been prevented.”

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Health

Ultraprocessed foods linked to ovarian and other cancer deaths, study finds

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CNN
 — 

Eating more ultraprocessed foods raises the risk of developing and dying from cancer, especially ovarian cancer, according to a new study of over 197,000 people in the United Kingdom, over half of whom were women.

Overly processed foods include prepackaged soups, sauces, frozen pizza and ready-to-eat meals, as well as hot dogs, sausages, french fries, sodas, store-bought cookies, cakes, candies, doughnuts, ice cream and many more.

“Ultra-processed foods are produced with industrially derived ingredients and often use food additives to adjust colour, flavour, consistency, texture, or extend shelf life,” said first author Dr. Kiara Chang, a National Institute for Health and Care Research fellow at Imperial College London’s School of Public Health, in a statement.

“Our bodies may not react the same way to these ultra-processed ingredients and additives as they do to fresh and nutritious minimally processed foods,” Chang said.

However, people who eat more ultra-processed foods also tend to “drink more fizzy drinks and less tea and coffee, as well as less vegetables and other foods associated with a healthy dietary pattern,” said Duane Mellor, a registered dietitian and senior teaching fellow at Aston Medical School in Birmingham, UK, in an email.

“This could mean that it may not be an effect specifically of the ultra-processed foods themselves, but instead reflect the impact of a lower intake of healthier food,” said Mellor, who was not involved in the study.

The study, published Tuesday in the journal eClinicalMedicine, looked at the association between eating ultraprocessed foods and 34 different types of cancer over a 10-year period.

Researchers examined information on the eating habits of 197,426 people who were part of the UK Biobank, a large biomedical database and research resource that followed residents from 2006 to 2010.

The amount of ultraprocessed foods consumed by people in the study ranged from a low of 9.1% to a high of 41.4% of their diet, the study found.

Eating patterns were then compared with medical records that listed both diagnoses and deaths from cancer.

Each 10% increase in ultraprocessed food consumption was associated with a 2% increase in developing any cancer, and a 19% increased risk for being diagnosed with ovarian cancer, according to a statement issued by Imperial College London.

Deaths from cancers also increased, the study found. For each additional 10% increase in ultraprocessed food consumption, the risk of dying from any cancer increased by 6%, while the risk of dying from ovarian cancer rose by 30%, according to the statement.

“These associations persisted after adjustment for a range of socio-demographic, smoking status, physical activity, and key dietary factors,” the authors wrote.

When it comes to death from cancer among women, ovarian cancer is ranked fifth, “accounting for more deaths than any other cancer of the female reproductive system,” noted the American Cancer Society.

“The findings add to previous studies showing an association between a greater proportion of ultra-processed foods (UPFs) in the diet and a higher risk of obesity, heart attacks, stroke, and type 2 diabetes,” said Simon Steenson, a nutrition scientist at the British Nutrition Foundation, a charity partially supported by food producers and manufacturers. Steenson was not involved in the new study.

“However, an important limitation of these previous studies and the new analysis published today is that the findings are observational and so do not provide evidence of a clear causal link between UPFs and cancer, or the risk of other diseases,” Steenson said in an email.

People who ate the most ultraprocessed foods “were younger and less likely to have a family history of cancer,” Chang and her colleagues wrote.

High consumers of ultraprocessed foods were less likely to do physical activity and more likely to be classified as obese. These people were also likely to have lower household incomes and education and live in the most underprivileged communities, the study found.

“This study adds to the growing evidence that ultra-processed foods are likely to negatively impact our health including our risk for cancer,” said Dr. Eszter Vamos, the study’s lead author and a clinical senior lecturer at Imperial College London’s School of Public Health in a statement.

This latest research is not the first to show an association between a high intake of ultraprocessed foods and cancer.

A 2022 study examined the diets of over 200,000 men and women in the United States for up to 28 years and found a link between ultraprocessed foods and colorectal cancer — the third most diagnosed cancer in the United States — in men, but not women.

And there are “literally hundreds of studies (that) link ultraprocessed foods to obesity, cancer, cardiovascular disease, and overall mortality,” Marion Nestle, the Paulette Goddard professor emerita of nutrition, food studies and public health at New York University told CNN previously.

While the new UK-based study cannot prove causation, only an association, “other available evidence shows that reducing ultra-processed foods in our diet could provide important health benefits,” Vamos said.

“Further research is needed to confirm these findings and understand the best public health strategies to reduce the widespread presence and harms of ultra-processed foods in our diet,” she added.

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Health

Infant screen time could impact academic success, study says

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CNN
 — 

Letting infants watch tablets and TV may be impairing their academic achievement and emotional well-being later on, according to a new study.

Researchers found that increased use of screen time during infancy was associated with poorer executive functioning once the child was 9 years old, according to the study published Monday in the journal JAMA Pediatrics.

Executive functioning skills are mental processes that “enable us to plan, focus attention, remember instructions, and juggle multiple tasks successfully,” according to the Harvard University Center on the Developing Child.

Those executive functioning skills are important for higher-level cognition, such as emotional regulation, learning, academic achievement and mental health, according to the study. They influence our success socially, academically, professionally and in how we care for ourselves, said Dr. Erika Chiappini, assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine in Baltimore.

“Though these cognitive processes naturally develop from infancy through adulthood, they are also impacted by the experiences that we have and when we have them in our development,” said Chiappini, who was not involved in the study, in an email.

The results support recommendations from the American Academy of Pediatrics, which discourages all screen time before 18 months old, with the exception of video chatting, said Dr. Joyce Harrison, associate professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine. Harrison was not involved in the research.

The study looked at data from Growing Up in Singapore Towards healthy Outcomes, or GUSTO, which surveyed women from all socioeconomic backgrounds during their first trimester of pregnancy. The sample was made up of 437 children who underwent electroencephalography (EEG) scans, which are used to look at the neural pathways of cognitive functions in the brain, at age 1, 18 months and 9 years old.

The parents reported each child’s screen time, and researchers found there was an association between screen time in infancy and attention and executive function at 9 years old, according to the study.

Further research needs to be done, however, to determine if the screen time caused the impairments in executive function or if there are other factors in the child’s environment that predispose them to both more screen time and poorer executive functioning, the study noted.

In a learning-packed time like infancy, one of the big problems with screen use is that young children aren’t learning much from them, according to AAP.

“There is no substitute for adult interaction, modeling and teaching,” Harrison said.

Babies have a hard time interpreting information presented in two dimensions, such as on screens, and have trouble distinguishing fantasy from reality, Chiappini said.

“Babies and kids are also social learners and very much benefit from the back-and-forth interaction with others (adults and kids) which is hard to achieve with screens,” Chiappini said via email.

When it comes to emotional regulation, infants and toddlers can learn from their caregivers when they model self-control or help to label emotions and appropriate expressions, she added.

For example, you can give a young child options for what they can do when they are mad, like taking a break or breathing deeply instead of inappropriate behaviors like hitting, Harrison said.

Talking about emotions can be too abstract for preschool-age kids, and in those cases using color zones to talk about emotions can be helpful, said Dr. Jenny Radesky, a developmental behavioral pediatrician and associate professor of pediatrics at Michigan Medicine C.S. Mott Children’s Hospital. Radesky was not involved in the research.

Calm and content can be green; worried or agitated can be yellow; and upset or angry can be red, using graphics or images of faces to help kids match what they’re feeling with their color zone. To reinforce it, adults can talk about their own emotions in terms of colors in front of their kids, Radesky said in a CNN previous article.

Parents and children can go through the colors together and come up with calming tools for the different zones, she added.

To strengthen those executive function skills, Harrison says it’s important to provide structured engagement where a child can work through solving problems to the extent that they can at their developmental level — instead of having problems solved for them.

And yet, sometimes parents just need to get the laundry done or attend a work meeting, and screens can feel like an effective distraction.

For very young children, it’s probably still best to avoid screen time, Harrison emphasized.

Instead, try to involve the child in house chores, she said.

“Give your toddler some clothes to fold alongside you while you are trying to get laundry done or keep your infant safely in a position where you can make frequent eye contact while you are engaged your chore,” Harrison said via email.

For older preschoolers, save up your screen time to use strategically, she said.

“For example, their one hour of screen time can be reserved for a time when you have an important video meeting to attend,” Harrison said.

And there is some content that can help teach emotional regulation when your tank is empty. Finding media that is aimed at speaking to children directly about emotions — like Daniel Tiger or Elmo Belly Breathing — can be like a meditation instead of distraction, Radesky previously told CNN.

And you can make screen time works better by engaging your child while they watch, Chiappini said. Ask questions like “what is that character feeling?” and “what could they do to help their friend?” she added.

Raising children is a complex and sometimes overwhelming task, and no caregiver can give their child everything they want to all the time, Radesky said.

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Entertainment

MrBeast helps 1,000 blind people see again by sponsoring cataract surgeries

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CNN
 — 

YouTube superstar MrBeast is making the world clearer – for at least 1,000 people.

The content creator’s latest stunt is paying for cataract removal for 1,000 people who were blind or near-blind but could not afford the surgery.

“We’re curing a thousand people’s blindness,” says MrBeast – real name Jimmy Donaldson – in the Saturday video, which reached over 32 million views as of Sunday afternoon.

The video features touching before-and-after footage of patients seeing with clear vision after finishing the surgery. The YouTuber also gave cash donations and other gifts to some of the participants.

Jeff Levenson, an ophthalmologist and surgeon, worked with Donaldson to perform the first round of surgeries in Jacksonville, Florida. Levenson has coordinated the “Gift of Sight” program for over 20 years, which provides free cataract surgery for uninsured patients who are legally blind due to cataracts.

“Half of all blindness in the world is people who need a 10-minute surgery,” Levenson says in the video, referring to the cataract removal surgery.

Levenson explained to CNN he became inspired to help people access cataract surgery after undergoing his own cataract correction surgery.

“In the days and weeks after my own cataract surgery, I was stunned by how bright and beautiful and vivid the world was,” he said. “But I was shocked by the idea that there are hundreds of millions, probably 200 million people around the world, who are blind or nearly blind from cataracts and who don’t have access to the surgery.”

Levenson got a call from a member of Donaldson’s team in September. “I had never heard of MrBeast,” he said. “So I almost hung up. But I gratefully did not hang up.”

They started by calling homeless shelters and free clinics to create a list of patients in the Jacksonville area who needed cataract surgery but could not afford it. Eventually, they had a group of 40 patients – and Levenson performed all of their surgeries in a single day, starting at 7 a.m. and ending at 6 p.m.

Levenson said that patients were in “disbelief that somebody would actually seek them out to to rescue them from blindness, and then have the kindness and generosity of spirit to offer the surgery.”

The ophthalmologist also connected Donaldson’s team with SEE International, for which he serves as the chief medical officer. The nonprofit provides free eyecare around the world to patients in need. The organization helped Donaldson reach even more patients, for a total of 1,000 surgeries completed around three weeks. The video shows patients receiving the surgery in Jamaica, Honduras, Namibia, Mexico, Indonesia, Brazil, Vietnam and Kenya.

Levenson said he hopes the video and Donaldson’s generosity inspire “a concerted effort to end needless blindness.”

“If MrBeast can light a fire, and if we can get governmental and private support behind it, we can end half of all the blindness in the world,” he said. “Without all that much cost, and with incredible gains in human productivity and human potential.”

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Health

A few minutes of brisk activity can help your brain, study finds

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Editor’s Note: Seek advice from a health care provider before starting a workout program.



CNN
 — 

What if you could look at all the things you do daily — walking from room to room, preparing a presentation at your desk, running up and down stairs to deliver folded laundry or taking a jog around the block — and know which ones will best help or hurt your brain?

A new study attempted to answer that question by strapping activity monitors to the thighs of nearly 4,500 people in the United Kingdom and tracking their 24-hour movements for seven days. Researchers then examined how participants’ behavior affected their short-term memory, problem-solving and processing skills.

Here’s the good news: People who spent “even small amounts of time in more vigorous activities — as little as 6 to 9 minutes — compared to sitting, sleeping or gentle activities had higher cognition scores,” said study author John Mitchell, a Medical Research Council doctoral training student at the Institute of Sport, Exercise and Health at University College London, in an email.

Moderate physical activity is typically defined as brisk walking or bicycling or running up and down stairs. Vigorous movement, such as aerobic dancing, jogging, running, swimming and biking up a hill, will boost your heart rate and breathing.

The study, published Monday in the Journal of Epidemiology & Community Health, found doing just under 10 minutes of moderate to vigorous exertion each day improved study participants’ working memory but had its biggest impact on executive processes such as planning and organization.

The cognitive improvement was modest, but as additional time was spent doing the more energetic workout the benefits grew, Mitchell said.

“Given we don’t monitor participants’ cognition over many years, this may be simply that those individuals who move more tend to have higher cognition on average,” he said. “However, yes, it could also imply that even minimal changes to our daily lives can have downstream consequences for our cognition.”

Steven Malin, an associate professor in the department of kinesiology and health at Rutgers University in New Jersey, told CNN the study provides new insight in how activity interacts with sedentary behavior as well as sleep.

“Understanding the interaction of sleep and various physical activities is often not examined,” said Malin, who was not involved in the new study.

While the study had some limitations, including a lack of knowledge about the health of the participants, the findings illustrate how “the accumulation of movement patterns in a day to a week to a month is just as, if not more important, than just getting outside for a single session of exercise,” he said.

There was bad news as well: Spending more time sleeping, sitting or engaged only in mild movement was linked to a negative impact on the brain. The study found cognition declined 1% to 2% after replacing an equivalent portion of moderate to vigorous physical activity with eight minutes of sedentary behavior, six minutes of light intensity or seven minutes of sleep.

“In most cases we showed that as little as 7 to 10 minutes less MVPA (moderate to vigorous physical activity) was detrimental,” Mitchell said.

That change is only an association, not a cause and effect, due to the observational methods of the study, Mitchell stressed.

In addition, the study’s findings on sleep can’t be taken at face value, he said. Good quality sleep is critical for the brain to operate at peak performance.

“The evidence on the importance of sleep for cognitive performance is strong,” Mitchell said, “yet there are two major caveats. First, over-sleeping can be linked to poorer cognitive performance.

“Secondly, sleep quality may be even more important than duration. Our accelerometer devices can estimate how long people slept for, but cannot tell us how well they slept.”

Additional studies need to be done to verify these findings and understand the role of each type of activity. However, Mitchell said, the study “highlights how even very modest differences in people’s daily movement — less than 10 minutes — is linked to quite real changes in our cognitive health.”

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Health

A few minutes of brisk activity can help your brain, study finds

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Editor’s Note: Seek advice from a health care provider before starting a workout program.



CNN
 — 

What if you could look at all the things you do daily — walking from room to room, preparing a presentation at your desk, running up and down stairs to deliver folded laundry or taking a jog around the block — and know which ones will best help or hurt your brain?

A new study attempted to answer that question by strapping activity monitors to the thighs of nearly 4,500 people in the United Kingdom and tracking their 24-hour movements for seven days. Researchers then examined how participants’ behavior affected their short-term memory, problem-solving and processing skills.

Here’s the good news: People who spent “even small amounts of time in more vigorous activities — as little as 6 to 9 minutes — compared to sitting, sleeping or gentle activities had higher cognition scores,” said study author John Mitchell, a Medical Research Council doctoral training student at the Institute of Sport, Exercise and Health at University College London, in an email.

Moderate physical activity is typically defined as brisk walking or bicycling or running up and down stairs. Vigorous movement, such as aerobic dancing, jogging, running, swimming and biking up a hill, will boost your heart rate and breathing.

The study, published Monday in the Journal of Epidemiology & Community Health, found doing just under 10 minutes of moderate to vigorous exertion each day improved study participants’ working memory but had its biggest impact on executive processes such as planning and organization.

The cognitive improvement was modest, but as additional time was spent doing the more energetic workout the benefits grew, Mitchell said.

“Given we don’t monitor participants’ cognition over many years, this may be simply that those individuals who move more tend to have higher cognition on average,” he said. “However, yes, it could also imply that even minimal changes to our daily lives can have downstream consequences for our cognition.”

Steven Malin, an associate professor in the department of kinesiology and health at Rutgers University in New Jersey, told CNN the study provides new insight in how activity interacts with sedentary behavior as well as sleep.

“Understanding the interaction of sleep and various physical activities is often not examined,” said Malin, who was not involved in the new study.

While the study had some limitations, including a lack of knowledge about the health of the participants, the findings illustrate how “the accumulation of movement patterns in a day to a week to a month is just as, if not more important, than just getting outside for a single session of exercise,” he said.

There was bad news as well: Spending more time sleeping, sitting or engaged only in mild movement was linked to a negative impact on the brain. The study found cognition declined 1% to 2% after replacing an equivalent portion of moderate to vigorous physical activity with eight minutes of sedentary behavior, six minutes of light intensity or seven minutes of sleep.

“In most cases we showed that as little as 7 to 10 minutes less MVPA (moderate to vigorous physical activity) was detrimental,” Mitchell said.

That change is only an association, not a cause and effect, due to the observational methods of the study, Mitchell stressed.

In addition, the study’s findings on sleep can’t be taken at face value, he said. Good quality sleep is critical for the brain to operate at peak performance.

“The evidence on the importance of sleep for cognitive performance is strong,” Mitchell said, “yet there are two major caveats. First, over-sleeping can be linked to poorer cognitive performance.

“Secondly, sleep quality may be even more important than duration. Our accelerometer devices can estimate how long people slept for, but cannot tell us how well they slept.”

Additional studies need to be done to verify these findings and understand the role of each type of activity. However, Mitchell said, the study “highlights how even very modest differences in people’s daily movement — less than 10 minutes — is linked to quite real changes in our cognitive health.”

Read original article here

Health

Many women underestimate breast density as a risk factor for breast cancer, study shows

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CNN
 — 

Dense breast tissue has been associated with up to a four times higher risk of breast cancer. However, a new study suggests few women view breast density as a significant risk factor.

The study, published in JAMA Network Open, surveyed 1,858 women ages 40 to 76 years from 2019 to 2020 who reported having recently undergone mammography, had no history of breast cancer and had heard of breast density.

Women were asked to compare the risk of breast density to five other breast cancer risk factors: having a first-degree relative with breast cancer, being overweight or obese, drinking more than one alcoholic beverage per day, never having children and having a prior breast biopsy.

“When compared to other known and perhaps more well-known breast cancer risks, women did not perceive breast density as significant of a risk,” said Laura Beidler, an author of the study and researcher at the Dartmouth Institute for Health Policy and Clinical Practice.

For example, the authors report that dense breast tissue is associated with a 1.2 to four times higher risk of breast cancer compared with a two times higher risk associated with having a first-degree relative with breast cancer – but 93% of women said breast density was a lesser risk.

Dense breasts tissue refers to breasts that are composed of more glandular and fibrous tissue than fatty tissue. It is a normal and common finding present in about half of women undergoing mammograms.

The researchers also interviewed 61 participants who reported being notified of their breast density and asked what they thought contributes to breast cancer and how they could reduce their risk. While most women correctly noted that breast density could mask tumors on mammograms, few women felt that breast density could be a risk factor for breast cancer.

Roughly one-third of women thought there was nothing they could do to reduce their breast cancer risk, although there are several ways to reduce risk, including maintaining a healthy, active lifestyle and minimizing alcohol consumption.

Breast density changes over a woman’s lifetime, and is generally higher in women who are younger, have a lower body weight, are pregnant or breastfeeding, or are taking hormone replacement therapy.

The level of breast cancer risk increases with the degree of breast density; however, experts aren’t certain why this is true.

“One hypothesis has been that women who have more dense breast tissue also have higher, greater levels of estrogen, circulating estrogen, which contributes to both the breast density and to the risk of developing breast cancer,” said Dr. Harold Burstein, a breast oncologist at the Dana-Farber Cancer Institute who was not involved in the study. “Another hypothesis is that there’s something about the tissue itself, making it more dense, that somehow predisposes to the development of breast cancer. We don’t really know which one explains the observation.”

Thirty-eight states currently mandate that women receive written notification about their breast density and its potential breast cancer risk following mammography; however, studies have shown that many women find this information confusing.

“Even though women are notified usually in writing when they get a report after a mammogram that says, ‘You have increased breast density,’ it’s kind of just tucked in there at the bottom of the report. I’m not sure that anyone is explaining to them, certainly in person or verbally, what that means,” said Dr. Ruth Oratz, a breast oncologist at NYU Langone’s Perlmutter Cancer Center who was not involved in the study.

“I think what we’ve learned from this study is that we have to do a better job of educating not only the general public of women, but the general public of health care providers who are doing the primary care, who are ordering those screening mammograms,” she added.

Current screening guidelines recommend women of average risk of breast cancer undergo breast cancer screening every one to two years between ages 50 to 74 with the option of beginning at age 40.

Because women with dense breast tissue are considered to have higher than average cancer risks, the authors of the study suggest women with high breast density may benefit from supplemental screening like breast MRI or breast ultrasound, which may detect cancers that are missed on mammograms. Currently, coverage of supplemental screening after the initial mammogram varies, depending on the state and insurance policy.

The authors warn that “supplemental screening not only can lead to increased rates of cancer detection but also may result in more false-positive results and recall appointments.” They say clinicians should use risk assessment tools when discussing tradeoffs associated with supplemental screening.

“Usually, it’s a discussion between the patient, the clinical team, and the radiologist. And it’ll be affected by prior history, by whether there’s anything else of concern on the mammogram, by the patient’s family history. So those are the kinds of things we discuss frequently with patients who are in such situations,” Burstein said.

Breast cancer screening recommendations differ between medical organizations, and experts say women at higher risk due to breast density should discuss with their doctor what screening method and frequency are most appropriate.

“I think it’s really, really important that everyone understands – and this is the doctors, the nurses, the women themselves – that screening is not a one size fits all recommendation. We cannot just make one general recommendation to the entire population because individual women have different levels of risks of developing breast cancer,” Oratz said.

For the nearly one-third of women with dense breast tissue that reported there was nothing they could do to prevent breast cancer, experts say there are some steps you can take to reduce your risk.

“Maintaining an active, healthy lifestyle and minimizing alcohol consumption address several modifiable factors. Breastfeeding can decrease the risk. On the other hand, use of hormone replacement therapy increases breast cancer risk,” said Dr. Puneet Singh, a breast surgical oncologist at the MD Anderson Cancer Center who was not involved in the study.

The researchers add that there are approved medications, such as tamoxifen, that can be given for those at significantly increased risk that may reduce the chances of breast cancer by about half.

Finally, breast cancer doctors say that in addition to appropriate screening, knowing your risk factors and advocating for yourself can be powerful tools in preventing and detecting breast cancer.

“At any age, if any woman feels uncomfortable about something that’s going on in her breast, if she has discomfort, notices a change in the breast, bring that to the attention of your doctor and make sure it gets evaluated and don’t let somebody just brush you off,” Oratz said.

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Health

Origins of plague could have emerged centuries before outbreaks, study suggests

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CNN
 — 

In the largest DNA analysis of its kind, scientists have found evidence to suggest that historic plague pandemics, such as the Black Death, were not caused by newly evolved strains of bacteria but ones that could have emerged up to centuries before their outbreaks.

The plague-causing bacterium Yersinia pestis is dated to have first emerged in humans about 5,000 years ago. Through animals and trade routes, Y. pestis spread globally over time on multiple occasions, according to a study published Thursday in the journal Communications Biology.

It caused the first plague pandemic in the sixth to eighth centuries and the second one in the 14th to 19th centuries. The latter pandemic is thought to have started with the medieval Black Death outbreak, which is estimated to have killed more than half of Europe’s population. The bacterium also caused the third plague pandemic between the 19th and 20th centuries.

By amassing 601 Y. pestis genome sequences, including modern and ancient strains, researchers from Canada and Australia were able to calculate the time when the bacterial strains likely emerged as a threat. They divided the different strains of the plague bacterium and analyzed each strain population individually.

The strain responsible for the Black Death, which the study says is thought to have begun in 1346, was newly estimated to have diverged from an ancestral strain between 1214 and 1315 — up to 132 years earlier.

The strain of Y. pestis associated with the first plague pandemic was previously recorded as first appearing during the Plague of Justinian, which began in 541. However, the researchers estimated that the strain was already present between 272 and 465 — up to almost 270 years before the outbreak.

“It shows that each major plague pandemic has likely emerged many decades to centuries earlier than what the historical record suggests,” study coauthor and evolutionary geneticist Hendrik Poinar, director of McMaster University’s Ancient DNA Centre in Canada, told CNN via email Thursday.

He added that the bacterium emerged, created small epidemics and then “for reasons we don’t quite understand,” such as famine or war, “it takes off.”

The study authors estimated that individually assessed bacterial strains from the third plague pandemic diverged from an ancestral strain between 1806 and 1901, with highly localized plague cases beginning to appear in southern China between 1772 and 1880 and later diverging into various strains that spread globally out of Hong Kong between 1894 and 1901.

The study also found evidence to support recent academic research suggesting that the third and second plague pandemics were not mutually exclusive events, but that the third was partly the continuation or tail end of the second. Despite the pandemics having their own diverse genetic lineages that evolved differently, the third descended directly from the 14th century strain that caused the second.

Poinar called this finding significant because “it takes into account that most of the history of this bacterium has been a Eurocentric view, so while plague supposedly disappeared from Europe in the 18th (century), it continued to rage in the Ottoman Empire and throughout the Middle East and likely North Africa.”

However, even with so many sequences of the plague bacterium, researchers were not able to determine the path of the global spread of the plague.

A lot of the genetic samples come from Europe. For example, the emergence of the bacterium in Africa has led to 90% of all modern plague cases occurring on the continent, yet there are no ancient sequences from the region, which is represented by just 1.5% of all genome samples — making it difficult to date the appearance of Y. pestis in Africa.

There is also far less surviving historical evidence from the second plague pandemic to help estimate its geographic origins compared with the third, with the earliest textual evidence of the pandemic in Europe coming from the Black Death in 1346, the study authors said. The researchers estimated that the second pandemic originated in Russia.

A study published in the journal Nature in June used DNA analysis to find the plague bacterium in three individuals who are dated to have died in 1338 in what’s now Kyrgyzstan in Central Asia. It provided evidence that the Black Death came from a strain originating in the area near Lake Issyk-Kul in Kyrgyzstan in the early 14th century.

The latest study concluded that more ancient DNA will be needed to refine current estimates on the early events of the second pandemic.

Via email, Poinar described the strain from Kyrgyzstan as “really fascinating” but said that it “still doesn’t sit at the root. So I would guess we’re still looking for something a good 20-50 years earlier.”

He and the other authors noted that the only way to estimate the evolution of the plague bacterium strains precisely “is with well dated sequences, such as those from skeletal remains at Lake Issyk-Kul.”

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Health

Decreasing rates of childhood immunization are a major concern. Our medical analyst explains why

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CNN
 — 

Vaccine rates for measles, polio, diphtheria and other diseases are decreasing among US children, according to a new study from the US Centers for Disease Control and Prevention.

The rate of immunizations for required vaccines among kindergarten students declined from 95% to approximately 94% during the 2020-21 school year. It dropped further — to 93% — in the 2021-22 school year.

That’s still a high number, so why is this drop in immunization significant? What accounts for the decline? What might be the consequences if these numbers drop further? If parents are unsure about vaccinating their kids, what should they do? And what can be done on a policy level to increase immunization numbers?

To help us with these questions, I spoke with CNN Medical Analyst Dr. Leana Wen, an emergency physician, public health expert and professor of health policy and management at the George Washington University Milken Institute School of Public Health. She is also author of “Lifelines: A Doctor’s Journey in the Fight for Public Health.”

CNN: Why is it a problem that childhood immunization rates are declining?

Dr. Leana Wen: The reduction of vaccine-preventable diseases is one of the greatest public health success stories in the last 100 years.

The polio vaccine was introduced in the United States in 1955, for example. In the four years prior, there were an average of over 16,000 cases of paralytic polio and nearly 2,000 deaths from polio each year across the US. Widespread use of the polio vaccine had led to the eradication of polio in the country by 1979, according to the CDC, sparing thousands of deaths and lifelong disability among children each year.

The measles vaccine was licensed in the US in 1963. In the four years before that, there were an average of over 500,000 cases and over 430 measles-associated deaths each year. By 1998, there were just 89 cases recorded — and no measles-associated deaths.

These vaccines are very safe and extremely effective. The polio vaccine, for example, is over 99% effective at preventing paralytic polio. The measles vaccine is 97% effective at preventing infection.

We can do this same analysis for other diseases for which there are routine childhood immunizations.

It’s very concerning that rates of immunization are declining for vaccines that have long been used to prevent disease and reduce death. That means more children are at risk for severe illness — illness that could be averted if they were immunized. Moreover, if the proportion of unvaccinated individuals increases in a community, this also puts others at risk. That includes babies too young to be vaccinated or people for whom the vaccines don’t protect as well — for example, patients on chemotherapy for cancer.

CNN: What accounts for the decline in vaccination numbers?

Wen: There are probably many factors. First, there has been substantial disruption to the US health care system during the Covid-19 pandemic. Many children missed routine visits to the pediatrician during which they would have received vaccines due to pandemic restrictions. In addition, some community health services offered also became disrupted as local health departments focused on Covid-19 services.

Second, disruption to schooling has also played a role. Vaccination requirements are often checked prior to the start of the school year. When schools stopped in-person instruction, that led to some families falling behind on their immunizations.

Third, misinformation and disinformation around Covid-19 vaccines may have seeded doubt in other vaccines. Vaccine hesitancy and misinformation were already major public health concerns before the coronavirus emerged, but the pandemic has exacerbated the issues.

According to a December survey published by the Kaiser Family Foundation, more than one in three American parents said vaccinating children against measles, mumps, and rubella shouldn’t be a requirement for them to attend public schools, even if that may create health risks for others. This was a substantial increase from 2019, when a similar poll from the Pew Research Center found only 23% of parents opposed school vaccine requirements.

CNN: What are some consequences if immunization rates drop further?

Wen: If immunization rates drop further, we could see more widespread outbreaks. Diseases that were virtually eliminated in the US could reemerge, and more people can become severely ill and suffer lasting consequences or even die.

We are already seeing some consequences: Last summer, there was a confirmed case of paralytic polio in an unvaccinated adult in New York. It’s devastating that a disease like polio has been identified again in the US, since we have an extremely effective vaccine to prevent it.

There is an active measles outbreak in Ohio. As of January 17, 85 cases have been reported. Most of the cases involved unvaccinated children, and at least 34 have been hospitalized.

CNN: If parents are unsure of vaccinating their kids, what should they do?

Wen: As parents, we generally trust pediatricians with our children’s health. We consult pediatricians if our kids are diagnosed with asthma and diabetes, or if they have new worrisome symptoms of another illness. We should also consult our pediatricians about childhood immunizations; parents and caregivers with specific questions or concerns should address them.

The national association of pediatricians, the American Academy of Pediatrics, “strongly recommends on-time routine immunization of all children and adolescents according to the Recommended Immunization Schedules for Children and Adolescents.”

CNN: What can be done to increase immunization numbers?

Wen: There needs to be a concerted educational campaign to address why vaccination against measles, mumps, rubella, chickenpox, polio and so forth is so crucial. One of the reasons for vaccine hesitancy, in my experience, is that these diseases have been rarely seen in recent years. Many people who are parents now didn’t experience the devastation of these diseases growing up, so may not realize how terrible it would be for them to return.

Specific interventions should be targeted at the community level. In some places, low immunization levels may be due to access. Vaccination drives at schools, parks, shopping centers, and other places where families gather can help increase numbers. In other places, the low uptake may be because of vaccine hesitancy and misinformation. There will need to be different strategies implemented in that situation.

Overall, increasing immunization rates for vaccine-preventable childhood diseases needs to be a national imperative. I can’t underscore how tragic it would be for kids to suffer the harms of diseases that could be entirely prevented with safe, effective and readily available vaccines that have been routinely given for decades.

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