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Comment by Dr. Krishna Kumari Challa 11 hours ago

Daytime napping patterns may reveal hidden health decline in older adults

New research reveals that as people age, naps may be an easily trackable warning sign of underlying conditions or declining health. 

A new study by investigators  followed 1,338 older adults for up to 19 years to track napping habits and associated mortality rates. They found longer, more frequent, and morning naps were associated with higher mortality rates.

Excessive napping later in life has been linked to neurodegeneration, cardiovascular diseases and even greater morbidity.

Between 20 and 60% of older adults take naps. While infrequent napping can be restorative, excessive daytime napping in old age has been linked to a wide range of health issues.

19 years' worth of data were collected from 1,338 total participants. The researchers analyzed the data for associations between napping patterns at the initial assessment and all-cause mortality during the 19-year follow-up, finding that longer, more frequent, and 'morning naps' were all associated with higher mortality.
Each additional hour of daytime napping per day was associated with around 13% higher mortality risk; each extra nap per day was associated with around 7% higher mortality risk; and morning nappers had 30% higher mortality risk compared to afternoon nappers. Irregular napping patterns were not associated with any increased mortality risk.

It is important to note that this is correlation not causation. Excessive napping is likely indicating underlying disease, chronic conditions, sleep disturbances, or circadian dysregulation

Now that we know there is a strong correlation between napping patterns and mortality rates, we can make the case to implement wearable daytime nap assessments to predict health conditions and prevent further decline.

Objectively Measured Daytime Napping and All-cause Mortality in Older Adults, JAMA Network Open (2026). DOI: 10.1001/jamanetworkopen.2026.7938

Comment by Dr. Krishna Kumari Challa 12 hours ago

How nanomedicine gets inside your cells and treats you from the inside out

Nanomedicine uses engineered nanoparticles to deliver RNA-based drugs into cells, enabling precise control of protein production. Synthetic mRNA can be delivered to compensate for missing or defective proteins, while small interfering RNA (siRNA) or antisense oligonucleotides (ASO) can silence overexpressed or harmful proteins. This approach allows for targeted, programmable treatment of diseases at the molecular level.

original article

Comment by Dr. Krishna Kumari Challa 12 hours ago

Sex differences in brain gene activity could explain why some disorders affect men and women differently

The physical differences between men and women are all too obvious, but the biological divide goes right down to the cellular level in the brain, according to a new study published in the journal Science.

While we have known for a long time that men and women face different risks for brain disorders such as depression and Alzheimer's, we haven't always known why.

Most previous research has focused on broad sections of brain tissue, but in this study, a team of researchers analyzed more than one million nuclei from six different cortical regions from 30 donors.

Previous MRI scans of these brain regions had shown physical differences in size or volume between the sexes. The scientists wanted to see if gene activity matched the physical differences seen on the scans.

The technique they used was single-nucleus RNA sequencing, which allows researchers to examine the genetic instructions within individual cells. Specifically, the focus was on how gene expression varies across different cell types and regions.

The study identified more than 3,000 genes that differ in expression between males and females. These differences included how genes are turned on or off and how active genes are in producing RNA messages that guide protein production. What's more, they aren't spread evenly across the brain, as the team explains, "Broader effects of sex on autosomal expression are captured in 13 core signatures with varying cell type versus region specificity."

For example, the differences were much stronger (a higher number of genes were behaving differently) in certain areas like the fusiform cortex, which is a part of the brain involved in face recognition and complex visual processing.

Some of the strongest variations were seen in glial cells, which insulate neurons, but perhaps not surprisingly, the biggest differences were in the sex chromosome genes (X and Y). However, hundreds of genes across the entire genome are also influenced by sex.

When it comes to disease risk, the study found that some of the genes showing sex differences are the same ones linked to brain conditions that affect men and women differently, such as autism, ADHD, Alzheimer's disease and mood disorders.

Alex R. DeCasien et al, Sex effects on gene expression across the human cerebral cortex at cell type resolution, Science (2026). DOI: 10.1126/science.aea9063

Comment by Dr. Krishna Kumari Challa on Sunday

DNA is in the air
The air around us is teeming with the DNA of various organisms, ranging from people to viruses. Over the past decade, researchers have been learning how to collect airborne DNA and use it to study the movement of individual species, entire ecosystems or even attacks with biological weapons. But some hurdles remain: scientists still aren’t sure for how long DNA can persist in the air, or how far it can travel. And some experts worry that DNA plucked from the air could inadvertently reveal the characteristics of people that haven’t consented to such analysis.

Airborne genetic material can be used to paint a picture of ecosystem health, watch for invasive species and even identify humans.

https://www.nature.com/articles/d41586-026-01099-2?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on Sunday

No Evidence Fluoride In Drinking Water Harms IQ, Finds Decades-Long Study

There is no evidence that adding low levels of fluoride to community drinking water affects children's IQ or brain function later in life, according to a new study that tracked more than 10,000 people from their teen years through to old age.

In many regions of the world, fluoride is added to water to improve communities' dental health: it's proven to strengthen teeth and reduce decay.

The new study, which draws on longitudinal data from 10,317 high school seniors from 1957 to 2021, when participants were 80, finds no association between community water fluoridation exposure and IQ, or other measures of cognitive function later in life.

But in 2025, a widely misinterpreted paper found that exposure to high doses of fluoride, well above the 0.7 mg/L recommended by the US Public Health Service, may be associated with lower IQ in children.

Skeptics, however, were quick to point out that the data used for this review are of poor quality and provide no reason to worry about fluoride in US drinking water.

The 2025 paper mainly reviewed studies conducted in China and India. No studies from the US were available. The studies also did not control for contaminants in water.

https://www.pnas.org/doi/10.1073/pnas.2536005123

Comment by Dr. Krishna Kumari Challa on Sunday

Carb-heavy foods drove weight gain without more calories by lowering energy burn

Carbohydrate-rich foods such as bread, wheat, and rice increased body weight and fat mass in mice without a significant rise in total caloric intake, primarily by reducing energy expenditure rather than promoting overeating. Metabolic changes included elevated blood fatty acids, decreased essential amino acids, hepatic fat accumulation, and upregulation of genes involved in lipid synthesis and transport. Discontinuing wheat flour intake rapidly reversed weight gain and metabolic abnormalities.

Shigenobu Matsumura et al, Wheat Flour Intake Promotes Weight Gain and Metabolic Changes in Mice, Molecular Nutrition & Food Research (2026). DOI: 10.1002/mnfr.70394

Comment by Dr. Krishna Kumari Challa on Sunday

Scientists make Parkinson's drug from plastic in world first
Engineered E. coli bacteria can convert polyethylene terephthalate (PET) plastic waste into levodopa, a key Parkinson’s disease treatment, offering a sustainable alternative to fossil fuel–based drug production. Similar biotechnological approaches have also enabled conversion of plastics into other pharmaceuticals, supporting the potential for a circular economy that repurposes plastic waste into valuable medicines.

https://www.nature.com/articles/s41893-026-01785-z

Comment by Dr. Krishna Kumari Challa on Sunday

Hospital delirium a 'red flag' for severe health decline

Delirium is an acute, fluctuating state of confusion, reduced awareness, and cognitive impairment, typically developing over hours or days due to underlying medical issues, infections, medication side effects, or substance withdrawal. Symptoms include hallucinations, poor focus, and emotional changes, categorized into hyperactive, hypoactive, or mixed types. It often lasts about one week but can persist, and it is most common in older adults or those hospitalized in intensive care.
Hospitalized older adults experiencing delirium face significantly increased risks of adverse outcomes, including doubled rates of falls and urinary incontinence, and 50–70% higher risks of pneumonia, fractures, stroke, sepsis, acute kidney injury, and pressure injuries. Delirium indicates multisystem vulnerability and warrants extended post-discharge care and prevention strategies.

Researchers found delirium was associated with a higher risk of 12 adverse outcomes, independent of frailty and pre-existing dementia, which shows it is a warning of longer-term vulnerability.
An episode of delirium in hospital doubled the risk of falls and urinary incontinence, and there was a 50% to 70% increased risk of pneumonia, fecal incontinence, fractures, stroke, hip fracture, sepsis, acute kidney injury, and pressure injury.

There was also a 20% to 30% higher risk of gastrointestinal bleeding and heart failure. These are very strong associations that highlight delirium as a red flag for multisystem vulnerability.

Markus J Haapanen et al, Delirium and adverse clinical outcomes: a matched cohort study in the UK Biobank, The Lancet Healthy Longevity (2026). DOI: 10.1016/j.lanhl.2025.100816

Comment by Dr. Krishna Kumari Challa on Sunday

PFAS directly shown to alter thyroid structure and function

Per- and polyfluoroalkyl substances are used across industries, and are present in waterproof clothing, makeup, carpets, upholstery, cookware, fast-food containers, and myriad other items we encounter in our daily lives.

Long-term exposure to PFOA, PFOS, and GenX PFAS compounds alters thyroid cellular structure and function in mice, disrupts critical signaling pathways including those linked to cancer, and increases thyroid-stimulating hormone levels. These findings provide direct evidence that PFAS exposure induces histological and functional changes in thyroid tissue, implicating PFAS in thyroid disease mechanisms.
PFAS are known for their confirmed and potentially detrimental health effects, which are hard to avoid when PFAS, which are known as "forever chemicals" considering how long they persist in the environment and in the human body (up to decades), are found in the water supply across the globe. As a result, millions of people around the world have PFAS in their blood, and PFAS have been linked to a disruption in the creation and availability of thyroid hormones. Studies also suggest that PFAS exposure increases thyroid cancer risk.
A recent paper sought to further our understanding of the effects of PFAS on the microscopic anatomy or histology of the thyroid. The paper was published in the Journal of the Endocrine Society.
Digging into the effects of three major PFAS compounds, PFOA, PFOS, and GenX, the paper's authors made three primary findings:

The three PFAS altered the thyroid's cellular function and structure in mice.
The PFAS altered several critical signaling pathways, including several involved in cancers.
PFAS treatment increased the levels of thyroid-stimulating hormone, which is necessary for the regulation of our metabolism.
These results directly tie PFAS exposure to changes in the histology and functioning of thyroid tissue. They also provided mechanistic clues as to how PFAS are involved in thyroid disease.

Heather A Hartmann et al, PFAS Alter Thyroid Histology and Cellular SignalingIn VitroandIn Vivo, Journal of the Endocrine Society (2025). DOI: 10.1210/jendso/bvaf210

Comment by Dr. Krishna Kumari Challa on Sunday

Losing teeth may lead to weight gain, researchers report

Tooth loss and poor oral health, particularly loss of functional molars, are associated with increased risk of weight gain in older adults, likely due to reduced chewing ability and subsequent dietary changes toward higher-calorie, softer foods. Over four years, individuals with fewer teeth had a higher likelihood of gaining at least 5% body weight.

Losing teeth might cause you to gain weight, a new study says.
But, how?
Weight gain is significantly associated with having fewer teeth or losing the bone and gums that support teeth, researchers recently reported in the Journal of Periodontology.

The loss of teeth affects a person's chewing ability, which can limit their healthy food choices, researchers said.

These findings add to the growing body of evidence that periodontal health plays an important role in overall health, especially as we age.
Maintaining healthy teeth and gums supports better nutrition, good habits and improved quality of life later in life.
Tooth loss can cause people to shun healthy fiber-rich foods like fruits and veggies in favor of softer eats that contain more calories, researchers said.

Molars that gnash together while chewing played a key role in weight loss risk, researchers found. People with missing molars had a 17% higher risk of weight gain.

Loss of functional tooth units, especially molars, were associated with higher odds of weight gain among older adults over 4 years," concluded the research team.
People hoping to maintain a healthy weight—or even lose some pounds—should include good oral health as part of their strategy, researchers suggested.

Functional tooth unit, periodontal status, and association with weight change in older adults, Journal of Periodontology (2026). doi.org/10.1002/jper.70100

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