These blood thinners may have an unexpected benefit for Alzheimer’s patients

 People who have both atrial fibrillation and Alzheimer's disease may experience slower cognitive decline when treated with newer NOAC blood thinners, according to research from Karolinska Institutet published in the European Heart Journal.

Atrial fibrillation is a common heart rhythm condition in older adults and also affects many people living with Alzheimer's disease. Doctors often prescribe blood thinners to these patients to reduce the chance of blood clots and stroke. Earlier research has suggested that anticoagulant treatment may lower the risk of developing dementia, but far less is known about whether these drugs influence cognitive decline after Alzheimer's disease has already been diagnosed.

"There are reasons to believe that the treatment could have a positive effect on cognition, for example by improving blood flow and reducing small-scale damage in the brain," says Maria Eriksdotter, professor at the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, and senior consultant in geriatric medicine at Karolinska University Hospital, who led the study.

Comparing Newer and Older Blood Thinners

Researchers analyzed information from SveDem (Swedish Register for Cognitive Disorders/Dementia), a national quality registry, and included 7,308 people diagnosed with both atrial fibrillation and Alzheimer's disease.

Participants were placed into three matched groups. One group received newer anticoagulants known as NOACs, another was treated with the older blood thinner warfarin (Waran), and the third did not receive any anticoagulant medication.

To track changes in thinking and memory over time, researchers used the standardized Mini-Mental State Examination (MMSE).

Slower Cognitive Decline With NOACs

People taking NOACs showed a significantly slower decline in cognitive function than those treated with warfarin or those who received no anticoagulant medication.

The difference amounted to slightly more than 0.2 MMSE points per year. While that change is relatively small over a single year, the researchers say it could become more meaningful if it continues over a longer period.

"The difference is modest for an individual patient from one year to the next, but over a longer period even such an effect could influence how cognitive function develops. Our findings suggest that NOAC treatment may also be significant for cognition in this patient group," says Nanbo Zhu, researcher at the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet.

Lower Risks of Stroke and Other Complications

The potential benefits were not limited to cognition. Compared with people who did not receive anticoagulants, those treated with NOACs also had lower risks of death, stroke, blood clots and fractures.

Source: ScienceDaily

A deadly ebola relative is surging after years in the shadows

 A growing outbreak of the rare Bundibugyo virus in the Democratic Republic of Congo is drawing attention to a broader problem in global health: how to prepare for dangerous diseases that appear only rarely but can still cause deadly outbreaks.

In a review article published in the New England Journal of Medicine, Boston University professor Nancy Sullivan argues that outbreak preparedness needs to extend beyond the infectious diseases that receive the most attention.

A Rare Relative of Ebola

Bundibugyo belongs to the filovirus family, the same group of viruses that includes the much better-known Ebola virus. Despite its potential severity, Bundibugyo has been linked to only two previously recognized outbreaks, one in Uganda in 2007 and another in the Democratic Republic of Congo (DRC) in 2012.

The current outbreak, however, has already surpassed those earlier events in both its trajectory and scale. According to the WHO, 695 confirmed cases and 138 confirmed deaths had been reported in the DRC and Uganda as of June 11.

Sullivan, a professor of biology and virology, immunology & microbiology at Boston University, explains that bringing an outbreak under control depends on several measures working quickly together. These include rapid diagnosis, isolating infected patients, tracing people who may have been exposed, strengthening infection control, and providing supportive medical care.

Those steps become much harder when laboratory resources are limited. In settings where testing capacity is scarce, delays in confirming infections can give the virus more time to spread.

A Severe Hemorrhagic Fever

Bundibugyo can cause a severe form of hemorrhagic fever. Infection can trigger widespread inflammation, damage and failure of the cells lining blood vessels, uncontrolled bleeding, and failure of multiple organs.

The virus spreads through direct contact with infected bodily fluids. That creates particular risks for family members, caregivers, and health workers, especially when patients are being treated in hospitals without adequate infection control. The 2026 outbreak was formally recognized after the death of a nurse.

Another major challenge is that Bundibugyo can initially resemble several far more common illnesses. Symptoms overlap with malaria, typhoid fever, and other diseases, meaning laboratory testing is necessary to confirm an infection.

Testing Delays Can Slow the Response

Laboratory access remains limited in parts of the DRC, Sullivan found, and samples may need to travel considerable distances to reach national reference laboratories. That can turn a critical diagnosis into a lengthy process.

"Delays in specimen collection, transportation and testing can postpone confirmation by days or weeks, which hinders the isolation of infected persons, contact tracing and the initiation of outbreak-control measures," Sullivan wrote.

Those delays can be especially damaging during an outbreak, when identifying cases quickly is essential for separating infected people from others and finding anyone who may have been exposed.

The Risk of Overlooking Rare Viruses

The Bundibugyo outbreak also points to a larger weakness in preparedness strategies that concentrate heavily on the most familiar high-risk pathogens.

For decades, Bundibugyo caused relatively little recognized activity. Its return as a significant threat illustrates how difficult it can be to predict which infectious disease will drive the next major outbreak.

Sullivan has argued that medical countermeasures should be developed more broadly for pathogens capable of causing severe illness or death in humans, rather than focusing only on viruses already known to cause frequent outbreaks.

No Licensed Bundibugyo Vaccine

Considerable progress has been made toward vaccines and other medical countermeasures for the Ebola, Sudan and Marburg viruses. Bundibugyo, however, occurs much less often, and no licensed vaccine or therapeutic has been developed specifically to target it.

There are encouraging signs that vaccines designed against other virus species could offer at least some protection, but Bundibugyo remains an example of a dangerous pathogen for which dedicated medical tools are limited.

Sullivan says preparedness also needs to involve much more than creating diagnostic tests, vaccines and drugs. Health systems must be capable of coordinating quickly when outbreaks spread across borders.

Source: ScienceDaily

Ancient DNA reveals how plague kept returning for 400 years after the Black Death

 The Black Death is best known for the catastrophic wave of plague that swept through Europe between 1347 and 1353, killing millions of people. But the disease did not vanish once that initial disaster passed. Plague returned again and again for more than four centuries, repeatedly disrupting cities, economies, and societies across Europe and surrounding regions.

A study led by researchers at the University of Tartu is now offering a much more detailed look at what happened during those centuries. By analyzing DNA from the plague bacterium preserved in archaeological human remains, scientists were able to reconstruct how the disease spread, evolved, and repeatedly reappeared long after the Black Death.

Ancient DNA Reveals Centuries of Plague

The team reconstructed 26 genomes of Yersinia pestis, the bacterium that causes plague, from human remains recovered at 11 archaeological sites in Estonia, Russia, England, the Netherlands, and Switzerland. The samples date from the fourteenth through the eighteenth centuries, covering a large portion of the period known as the Second Plague Pandemic.

The genetic evidence suggests that plague did not simply survive in one place and repeatedly spread outward from a single source. Instead, the disease appears to have resurfaced in different parts of Europe over hundreds of years, potentially creating several new reservoirs where the bacterium could persist.

Estonia was repeatedly affected. Researchers found signs that plague entered the region multiple times during much of the Second Plague Pandemic, indicating that Estonia's connections with other parts of Europe also helped disease move across long distances.

One of the most striking patterns appeared around 1450-1500. During that period, plague lineages underwent a major expansion and split into three important branches. Those branches may have helped establish new reservoirs of Yersinia pestis in wild rodent populations.

Climate may also have influenced this expansion. The researchers point to the Great Renaissance Drought as one possible factor. Studies of modern plague systems have shown that changes in climate can strongly affect outbreaks among wild rodents, which act as natural hosts for the bacterium.

"We found evidence for repeated introductions of plague into Estonia starting already in the late 14th century and identified several previously unknown genetic lineages, both in urban and rural settings," said senior author Prof. Kristiina Tambets.

Pinpointing Ancient Plague Outbreaks

A major challenge in studying historical pandemics is figuring out exactly when ancient infections occurred.

During the COVID-19 pandemic, researchers could follow individual variants in remarkable detail because genome sequences were usually linked to precise dates. Ancient disease samples rarely come with that kind of information. Archaeological remains are often dated using radiocarbon techniques that can produce time windows spanning many decades or even more than a century.

"With COVID-19, scientists could reconstruct the spread of individual strains extremely well because the genomes came with precise timestamps. For historical pandemics, those timestamps are often missing or may cover more than 100 years, which limits our ability to interpret the genetic data," the main author, Dr. Marcel Keller, explained.

To address that problem, the team developed a method designed to narrow those broad dating ranges. Researchers examined where individual plague genomes appeared on the bacterium's evolutionary tree and used that information to refine the likely dates of many samples.

This allowed them to place ancient infections into a much more precise historical timeline.

The researchers then applied the improved dating approach to 64 previously published plague genomes and 11 newly sequenced genomes. Their work represents the first systematic attempt to connect nearly all plague genomes currently available from the fourteenth to eighteenth centuries with outbreaks described in historical records.

"We were able to improve dating intervals for many samples, which allowed us to connect them to specific plague waves and outbreaks that were recorded in the respective towns or regions by chroniclers," said historian and corresponding author Prof. Philip Slavin.

War Helped Plague Move Across Europe

The genetic record also shows how strongly human activity influenced the spread of plague.

Newly analyzed genomes provide additional evidence linking outbreaks to the Thirty Years' War (1618-1648) and the Great Northern War (c. 1700-1721). Armies, displaced civilians, refugees, and traders frequently traveled along the same routes, creating opportunities for disease to move between regions.

"We see how Yersinia pestis splits into new branches during periods of conflict and spreads along the routes traveled by troops and displaced populations," said senior author Dr. Christiana L. Scheib.

The findings add new detail to plague outbreaks connected with the Great Northern War. During the 1710 siege of Tallinn, for example, the disease killed Swedish and Russian soldiers as well as civilians.

Source: ScienceDaily

Scientists may have solved a 2,000-year-old Dead Sea Scrolls mystery

 A longstanding mystery surrounding the Dead Sea Scrolls may have a new explanation. Researchers have debated for decades whether the Qumran sect actually followed its unusual 364-day calendar or whether the system existed mainly as a religious and theoretical ideal.

A study from Tel Aviv University argues that both possibilities may be partly correct. According to the proposed reconstruction, the sect likely used the calendar during its early history, when disagreements over religious dates contributed to its separation from the Jerusalem establishment. Later, however, the system may have been abandoned because of a fundamental astronomical problem and changing political relations with the Hasmonean leadership under Alexander Jannaeus.

The research was conducted by Prof. Eshbal Ratzon of the Department of Jewish Philosophy and the Cohn Institute for the History and Philosophy of Science and Ideas at the Entin Faculty of Humanities. The findings were published in the Tarbiz Quarterly for Jewish Studies.

A Calendar Built Around 52 Perfect Weeks

The Qumran calendar differed sharply from the lunisolar calendar that shaped Jewish religious life during the Second Temple period.

Its year contained exactly 364 days, which can be divided evenly by seven. That produced 52 complete weeks every year and ensured that religious festivals always occurred on the same day of the week.

For members of the Qumran sect, this orderly structure was more than a mathematical convenience. They regarded it as reflecting a perfect divine system.

The calendar also carried political and religious significance. Authorities at the Temple in Jerusalem determined important dates using the prevailing calendar, but the Qumran sect rejected the idea that human leaders should have that power. Its members believed the dates had already been established by God during the Creation of the world and therefore should not be altered by people.

The Hidden Problem With 364 Days

The very feature that made the Qumran calendar so elegant also created a serious practical problem.

A 364-day year is about one day and a quarter shorter than the roughly 365-day astronomical year. That discrepancy seems small at first, but it grows steadily over time.

If the system were followed for twenty years without correction, religious festivals would shift by almost four weeks relative to the seasons. After several decades, a festival associated with spring could eventually fall in winter or even autumn.

That would have been especially troublesome for a community whose religious festivals were closely connected with agriculture, harvests, first fruits, and the seasonal cycle.

The problem can be compared with a clock that loses one minute every day. The error is barely noticeable at first, but after enough time passes, the clock no longer reflects the actual time.

Prof. Ratzon's study suggests that something similar may have happened with the Qumran calendar. Although the system was conceptually elegant and mathematically orderly, it gradually drifted farther away from the natural seasonal cycle it was meant to organize.

Was the Calendar Ever Really Used?

Scholars have offered several explanations for this puzzle over the years.

Some have proposed that the Qumran community periodically inserted additional days or weeks to keep the calendar aligned with the seasons. Others have argued that the 364-day system was never intended for everyday use and functioned only as an idealized religious framework.

Prof. Ratzon argues that the Dead Sea Scrolls do not clearly support either explanation.

Instead, she points to evidence suggesting that the calendar was deeply important to the sect's religious identity and formed a major part of its disagreement with the religious authorities in Jerusalem.

Nearly twenty scrolls discovered at Qumran address calendars and astronomy, an unusually large number that indicates how significant these subjects were to the community.

The Book of Jubilees, one of the important works preserved in the Qumran library, strongly criticizes the prevailing lunar calendar. It presents the 364-day system as the original calendar given to Moses on Mount Sinai.

A Calendar at the Center of a Religious Conflict

Drawing on this evidence, Prof. Ratzon proposes a different historical scenario.

She argues that the Qumran sect actively followed the 364-day calendar during its formative period in the second century BCE. The dispute over how sacred time should be measured may have intensified the sect's conflict with religious leaders in Jerusalem and contributed to its isolation.

But as the decades passed, the growing mismatch between the calendar and the seasons would have become increasingly difficult to ignore.

Source: ScienceDaily

8 common food additives linked to high blood pressure and heart disease

 Common food preservatives found across the processed food supply may be associated with a greater risk of high blood pressure and cardiovascular disease, according to research published in the European Heart Journal.

The study was led by Dr. Mathilde Touvier, a research director at INSERM (the French National Institute for Health and Medical Research), and Anaïs Hasenböhler, PhD student, both from the Nutritional Epidemiology Research Team at the Université Sorbonne Paris Nord and Université Paris Cité, France.

Preservatives are added to foods for several reasons, including preventing the growth of bacteria and mold, slowing spoilage, and helping products maintain their color, flavor, or freshness for longer. Because these ingredients are so widely used, researchers wanted to better understand whether long-term exposure could be connected to cardiovascular health.

Ms. Hasenböhler said: "Food preservatives are used in hundreds of thousands of industrially processed foods. Experimental studies suggest that some preservative food additives may be harmful to cardiovascular health, but we have not had enough evidence on the impact of these ingredients in humans. As far as we know, this is the first study of its kind to investigate the links between a wide range of preservatives and cardiovascular health."

Tracking Diet and Heart Health in More Than 112,000 People

The work was conducted as part of NutriNet-Santé, a large ongoing research project examining the connections between nutrition and health. The analysis included 112,395 volunteers living across France.

Every six months, participants recorded everything they ate and drank during a three-day period. This gave researchers unusually detailed information about their diets rather than relying only on broad estimates of food consumption.

The research team then examined the ingredients in those foods and beverages, including the preservatives they contained. Participants were followed for an average of seven to eight years so researchers could track whether they developed high blood pressure or cardiovascular diseases such as heart attack, stroke, or angina.

Preservative exposure was nearly universal. During the first two years of participation, 99.5% of the volunteers consumed at least one food preservative.

Higher Preservative Intake Linked to Higher Risk

The strongest associations appeared among people consuming the largest amounts of certain preservatives.

Participants with the highest intake of 'non-antioxidant' preservatives had a 29% higher risk of hypertension than those consuming the lowest amounts. They also had a 16% higher risk of cardiovascular disease, which included heart attack, stroke and angina.

People who consumed the greatest amounts of antioxidant preservatives had a 22% higher risk of hypertension.

The two categories protect food in different ways. Non-antioxidant preservatives are generally used to prevent potentially harmful microorganisms, including bacteria and mold, from growing. Antioxidant preservatives instead slow oxidation, a chemical process that can cause foods to brown, develop unpleasant flavors, or become rancid.

Eight Common Preservatives Stood Out

Researchers also analyzed 17 of the preservatives most commonly consumed by participants.

Eight were specifically associated with a higher risk of high blood pressure: potassium sorbate (E202), potassium metabisulphite (E224), sodium nitrite (E250), ascorbic acid (E300), sodium ascorbate (E301), sodium erythorbate (E316), citric acid (E330) and extracts of rosemary (E392).

Ascorbic acid (E300) was also specifically associated with cardiovascular disease.

These findings do not mean that consuming one of these ingredients will necessarily cause high blood pressure or heart disease. The research was observational, meaning it identified statistical associations rather than proving that preservatives were directly responsible for the increased risks.

Dr. Touvier added: "This study has some limitations inherent to its observational design. However, the findings are based on highly detailed data, and we have taken account of other factors that can increase or lower the risk of cardiovascular disease. Experimental research in the literature consistently suggested that preservatives may cause oxidative stress in the body or affect the way the pancreas works.

"These results suggest we need a re-evaluation of the risks and benefits of these food additives by the authorities in charge, such as the EFSA in Europe and the FDA in the USA, for better consumer protection. In the meantime, these findings support existing recommendations to favor non-processed and minimally processed foods, and avoid unnecessary additives. Doctors and other healthcare professionals play a key role in explaining these recommendations to the public."

Source: ScienceDaily

Millions take calcium and vitamin D for bone health. A major review finds little benefit

 Calcium and vitamin D supplements are widely taken to support bone health, especially by older adults. But a large review published in The BMJ suggests that, for most older people, these supplements provide little to no meaningful protection against falls or broken bones.

Falls are a major health concern as people age. Nearly one in three adults aged 65 and older falls each year, and those falls can lead to fractures, chronic pain, loss of independence, reduced quality of life, and in some cases a move into residential care. Finding effective ways to prevent falls and fractures is therefore an important public health goal.

Longstanding Questions About Bone Supplements

Calcium and vitamin D have long been associated with bone health. Calcium is a major structural component of bone, while vitamin D helps the body absorb calcium and supports normal bone metabolism.

Even so, previous evidence reviews have generally found that taking calcium or vitamin D alone does not reduce fracture risk. Results have been less consistent when the two are taken together, and researchers have also remained uncertain about whether vitamin D can meaningfully reduce falls.

Despite those unanswered questions, vitamin D supplements (with or without calcium) are still commonly recommended by clinicians, guidelines, and regulatory agencies for bone health. Prescriptions have also risen substantially in recent years.

Researchers Reviewed 69 Randomized Trials

To get a clearer picture, researchers in Canada examined results from 69 randomized controlled trials involving 153,902 adults.

Randomized controlled trials are considered one of the strongest ways to test whether a treatment works because participants are assigned to different treatment groups, helping researchers reduce the influence of other factors.

The trials compared calcium supplements, vitamin D supplements, or a combination of the two with either a placebo or no treatment. Researchers focused on whether the supplements reduced fractures and falls.

The studies varied in quality, but the team assessed the risk of bias and the certainty of the evidence using established research methods.

Little Evidence of Meaningful Fracture Prevention

After setting thresholds for what would count as a clinically meaningful benefit, the researchers found little to no effect on the chance of experiencing any fracture.

For calcium supplements, that conclusion was based on moderate certainty evidence from 11 trials involving 9,067 participants.

For vitamin D supplements, the researchers found high certainty evidence from 36 trials involving 92,045 participants.

For calcium and vitamin D taken together, high certainty evidence from 15 trials involving 51,126 participants also showed little to no meaningful effect.

The same general pattern appeared when researchers looked at specific outcomes, including hip fractures and falls. Calcium, vitamin D, and combined supplementation all appeared to have little to no effect, with most of the evidence rated as moderate to high certainty.

Important Exceptions Remain

The researchers caution that some parts of the analysis were based on relatively small numbers of trials or participants, meaning those findings should be interpreted carefully.

The conclusions may also not apply to everyone. In particular, people with certain bone disorders or those receiving medication for osteoporosis may have different needs and should not assume the findings apply directly to them.

Still, the results remained broadly consistent when researchers accounted for factors including age, sex, previous fractures, previous falls, and average calcium intake from food. That consistency strengthened confidence in the overall conclusions.

Researchers Question Routine Supplementation

Based on the findings, the researchers say the evidence "does not support routine supplementation with calcium or vitamin D, or combined supplementation to prevent fractures and falls."

They also argue that clinicians, guideline panels, and regulatory agencies "should re-evaluate their general recommendations for calcium and vitamin D supplementation in light of current evidence."

Researchers writing in a linked editorial say more rigorous and well-powered trials are still needed to determine whether supplementation might benefit people at especially high risk.

Exercise May Offer More Meaningful Protection

For now, the editorial authors suggest shifting more attention and funding toward approaches that have already shown meaningful benefits for preventing falls and related injuries.

Source: ScienceDaily

Scientists discover a hidden “ID card” in cat urine

 Cats rely heavily on scent to learn about one another, often gathering information from urine and other odor marks left behind in their surroundings. These chemical traces can continue communicating long after the animal that produced them has moved on.

That creates a puzzle. Many odor molecules evaporate, break down, or change with time. If a scent is constantly evolving, how can another animal still determine who originally left it?

Researchers from Japan, Germany, and Spain, led by Iwate University, may have found part of the answer in domestic cats. Their experiments point to a group of unusual fatty acids that could serve as a lasting chemical signature in cat urine.

The scientists identified 13 branched-chain fatty acids (BFAs). The particular mixture and proportions of these compounds varied from one cat to another, yet remained relatively consistent within the same animal. Behavioral tests also showed that cats could detect differences between BFA profiles when the researchers controlled for other lipids in the urine.

The findings suggest that BFAs could function as a durable chemical "calling card" that helps preserve information about individual identity. The study will be published in Current Biology.

Cats Remember Individual Urine Scents

Before searching for the chemicals involved, the researchers first needed to establish that cats could distinguish urine from different individuals.

When cats encountered the same urine sample repeatedly, they gradually spent less time investigating it. But when urine from a different cat was introduced, their interest rose again, and they spent more time sniffing.

Remarkably, cats continued to show reduced responses to previously encountered urine odors even after gaps lasting months. That pattern suggests that cats may retain long-term memories of particular urine scents.

Researchers also examined the flehmen response, the characteristic open-mouthed expression often seen when cats investigate certain odors. Cats displayed this response more often when smelling unfamiliar urine than when smelling their own.

As the same urine was presented again and again, the flehmen response became less frequent. When urine from another cat was introduced, however, the response increased once more.

"After confirming that cats can distinguish individual urine odors, we used the flehmen response as a clue to identify urinary molecules that may contribute to individual scent recognition," said Professor Masao Miyazaki of Iwate University, who led the research project.

13 Unusual Fatty Acids Form Distinctive Profiles

Using the cats' behavior as a guide, the scientists narrowed their search to a lipid fraction in urine containing unusual BFAs.

They ultimately identified 13 of these compounds. Based on a review of existing scientific literature, the researchers found no previous reports of the same BFAs occurring in mammalian excretions or secretions.

What stood out was not simply the presence of the compounds, but the pattern they formed. Each cat had a BFA profile defined by the combination and relative abundance of the different fatty acids.

Those profiles varied considerably between animals, while remaining comparatively stable when the same cats were sampled on different dates.

Genetics also appeared to play some role. Related cats generally had more similar BFA patterns, although each animal still maintained its own distinguishable profile even within the same family.

The compounds also proved relatively durable. Many volatile chemicals responsible for urine odor begin changing quickly once urine is deposited. BFAs, by contrast, are semi-volatile and evaporate more slowly.

In urine-soaked samples stored at 25°C, the distinctive BFA profiles associated with individual cats remained comparatively stable for at least 24 hours.

Cats Can Detect the Chemical Differences

The researchers then tested whether the cats themselves could actually distinguish these BFA patterns.

They controlled the other lipid components in the urine samples and changed only the donor-derived BFA-containing fraction. Cats that had already become accustomed to the original sample began sniffing more again when the BFA fraction was switched.

That behavioral change provided evidence that cats can perceive differences among individual BFA compositions.

The result strengthens the idea that these fatty acids may carry meaningful information about identity rather than simply being unusual chemical byproducts.

Source: ScienceDaily