According to a study published in the November 6, 2024, online issue of Neurology, the medical journal of the American Academy of Neurology, older people who are sleepy during the day or lose interest in activities due to sleep issues may be more likely to develop a syndrome that can lead to dementia.

People with the syndrome walk slowly and report memory problems, but they do not have a mobility handicap or dementia. Motoric cognitive risk syndrome is a condition that can develop before dementia.

What The Study Found?

The study found that people with excessive daytime sleepiness and a lack of enthusiasm to get things done were more likely to develop the syndrome than people without those sleep-related issues. The study does not prove that these sleep-related issues cause the syndrome, it only shows an association.

“Our findings emphasize the need for screening for sleep issues,” said study author Victoire Leroy, MD, PhD, of Albert Einstein College of Medicine in the Bronx, New York. “There’s potential that people could get help with their sleep issues and prevent cognitive decline later in life.”

How Was It Conducted?

The study included 445 participants, with an average age of 76, who did not have dementia. Participants completed sleep surveys at the beginning of the trial. They were queried about memory problems, and their walking pace was measured on a treadmill at the beginning of the study and then once a year for the next three years.

The sleep assessment included questions about how frequently people had difficulties sleeping because they woke up in the middle of the night, couldn't fall asleep within 30 minutes, or felt too hot or cold, as well as whether they used sleep aids. The question to assess excessive daytime drowsiness asks how frequently people have had problems remaining awake when driving, eating meals, or were engaged in any other activity.

The Findings

In total, 177 participants fit the category of bad sleepers, whereas 268 satisfied the definition of good sleepers.

At the outset of the trial, 42 participants had motoric cognitive risk syndrome. Throughout the trial, 36 more persons got the condition.

35.5% of patients who experienced extreme daytime sleepiness and a lack of enthusiasm developed the syndrome, compared to 6.7% who did not. After accounting for other factors that could influence the risk of the syndrome, such as age, depression, and other health conditions, researchers discovered that people with excessive daytime sleepiness and a lack of enthusiasm were more than three times more likely to develop the syndrome than those who did not have those sleep-related issues.

“More research needs to be done to look at the relationship between sleep issues and cognitive decline and the role played by motoric cognitive risk syndrome,” Leroy said. “We also need studies to explain the mechanisms that link these sleep disturbances to motoric cognitive risk syndrome and cognitive decline.”

A limitation of the study is that participants reported their own sleep information, so they may not have remembered everything accurately.

The study was supported by the National Institute on Aging.

Women's bodies have long been understudied, and even a simple touch can trigger unexpected sadness, anguish or homesickness. One such experience is Sad Nipple Syndrome (SNS), which many women may experience without knowing it has a name. Triggered by nipple stimulation, it remains poorly understood and largely unresearched.

Some describe it as sudden sadness or anguish, while others compare it to homesickness, nostalgia or an upsetting memory. Even putting on a shirt can trigger the sensation.

SNS is not an officially recognised medical diagnosis. Although it can affect anyone, it appears more common in women, according to the Cleveland Clinic.

Sad Nipple Syndrome Can Begin In Childhood

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Some people experience SNS from childhood without understanding what is happening.

“I was probably a child when I first noticed: ‘Why does touching my nipple make me sad?’” 28-year-old Sandra told The Guardian.

She kept the experience to herself until college, when she searched for answers online. “I realized I wasn’t crazy,” she said.

The Role Of Oxytocin And Dopamine

One possible explanation involves oxytocin, commonly known as the 'love hormone'.

Dr Vladimír Kraus from the Department of Gynaecology and Obstetrics at Pavol Jozef Šafárik University suggests oxytocin may be involved because nipple stimulation triggers its release.

Oxytocin plays a role in bonding and emotional connection. It is released during physical touch and also plays a role in childbirth and breastfeeding.

Kraus theorises that changes in oxytocin signalling could trigger negative emotions associated with SNS, although this has not been established.

A study found that breast stimulation increased oxytocin levels in both lactating and non-lactating women, suggesting the response is not limited to breastfeeding.

Maureen Sweeney, a psychiatric mental health nurse practitioner and women's behavioural health specialist at the Cleveland Clinic, suggests oxytocin release may also influence dopamine production. Reduced dopamine could contribute to dysphoric feelings, although this remains a proposed explanation.

Other possible factors include postpartum mental health, body image concerns, anxiety and intimate partner violence. Sweeney also points to premenstrual dysphoric disorder (PMDD), suggesting that some people may be more sensitive to normal hormonal fluctuations.

Read More: Breastfeeding Can Help Reduce Mothers' Risk of Type 2 Diabetes, Breast Cancer and More

How Is SNS Similar To D-MER And Post-Coital Dysphoria?

Dysphoric milk ejection reflex (D-MER) causes sudden negative emotions, such as sadness, homesickness and guilt, just before or during milk letdown while breastfeeding. It can also affect the breastfeeding experience and maternal bonding.Post-coital dysphoria (PCD), meanwhile, involves sadness, anxiety or irritability after sexual activity.

While SNS and D-MER are associated with nipple stimulation, PCD occurs after orgasm. Despite the different triggers, people can experience similar emotional and physical sensations, lactation consultant Alia Macrina Heise was quoted as saying to The Guardian.

She suggested hormonal interactions may be involved in all three conditions, although their precise mechanisms remain unclear.

Is There A Treatment For Sad Nipple Syndrome?

There are no specific treatments for SNS, and more research is needed to understand its causes. However, coping strategies and psychological support may help manage the distress. Sweeney suggests cognitive behavioural therapy (CBT) as one approach to addressing symptoms, even when a therapist is unfamiliar with SNS.

Per- and polyfluoroalkyl substances (PFAS), commonly known as forever chemicals, have sparked interests of epidemiologists who are investigating their links to chronic diseases like high blood pressure, cardiovascular conditions and certain cancers.

PFAS are a large group of chemicals made by humans that have been used in industrial processes and everyday consumer products. They are found in cosmetics, kitchen supplies, clothing, carpets, upholstery, food packaging and other household materials.

They are called forever chemicals because their strong chemical bonds make them resistant to breaking down in the environment. Some PFAS can also exist in the human body, allowing exposure to accumulate over time.

At the American Public Health Association's (APHA) 2026 Annual Meeting, researchers presented findings on how people are exposed to these chemicals everyday through food and drinking water, and what long-term health consequences may be related to that exposure.

Health Problems Linked To Forever Chemicals

Some studies have identified that PFAS exposure could lead to colon and liver cancers, low birth weight, development problems in children, complications during pregnancy and other metabolic disorders. Research has also identified its exposure to cholesterol, changes in liver enzymes, reduced antibody responses to some vaccines and hypertension during pregnancy.

However, this does not establish that PFAS exposure directly causes every condition reported in epidemiological studies. Health effects may depend on the chemical type, exposure levels, duration of exposure and individual factors.

The US Agency for Toxic Substances and Disease Registry (ATSDR) states that research into PFAS health effects is in progress.

Also read: Paper Straws Have 6.33 Times Higher Carcinogenic Risk Than Plastic Straws, Study Finds

Food Is A Significant Source Of PFAS

Besides drinking water, food can also contribute to exposure, prompting researchers to investigate whether dietary habits influence the relationship between PFAS and chronic health conditions.

One study conducted in Massachusetts examined the relationship between dietary patterns, PFAS exposure and blood pressure. Researchers found stronger associations between a specific PFAS compound and high blood pressure among people who regularly consumed fish.

Yuting Wang, a postdoctoral research fellow at Silent Spring Institute and one of the researchers involved in the study, said animal-based foods appeared to contain more PFAS than plant-based foods.

One possible explanation, she suggested, was that meat consumption could increase inflammation, which may influence the relationship between PFAS exposure and blood pressure.

"Better understanding interactions among diet, PFAS and blood pressure may improve clinical recommendations to prevent hypertension," Wang said. "Future studies should account for exposure to environmental pollutants in addition to nutrient benefits of certain food," she added.

Also read: Lancet Study Finds Air Pollution & Chemical Exposures Could Add To South Asia's Diabetes & Heart Disease Burden

PFAS Found In US Drinking Water Supplies

According to the US Geological Survey, approximately 45% of drinking water samples collected across the country showed traces of PFAS. Researchers have also investigated PFAS contamination in 11 townships in southeastern Pennsylvania. Their testing found that several drinking water supplies had PFAS concentrations exceeding the US Environmental Protection Agency's 2021 regulatory limits.

The team also examined two decades of mortality data from the townships to investigate whether areas with higher PFAS levels in public drinking water has different patterns of disease and death.

Erin Kulick, an assistant professor of epidemiology and biostatistics at Temple University College of Public Health who worked on the Pennsylvania study, said, "Southeastern Pennsylvania experiences overlapping burdens of PFAS exposure and cardiovascular disease."

Scientists Are Concerned About Long-Term Exposure

PFAS contamination is a public health concern because these chemicals can remain in the environment for long periods and reach people. Some PFAS accumulate in the body, and repeated exposure may increase the amount present over time.

The National Institutes of Health identifies several health concerns linked with exposure to certain PFAS, including immune system effects, increased cholesterol, liver changes, pregnancy-related complications and some cancers.

The US Environmental Protection Agency has established legally enforceable drinking water limits for six PFAS compounds, including perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).

Researchers say more comprehensive monitoring, better assessment and long-term epidemiological studies are needed to understand how PFAS contamination affects communities.

A simple five-factor risk score may help identify people at high risk of dementia, particularly in low- and middle-income countries (LMICs), where around 60% of the world's dementia cases now occur.

Developed and validated by researchers at Northumbria University, the risk score uses five everyday factors to identify older adults at higher risk of dementia. It aims to address a gap in dementia research, as existing prediction tools have largely been developed using data from high-income countries and may not work as well in lower-income settings.

The research team developed the model using data from more than 11,000 older adults across seven countries and three continents.

“We know the burden of dementia is shifting towards lower-income parts of the world, yet the prediction models clinicians and researchers rely on were designed with wealthier populations in mind. This model is a step towards changing that. It is simple, it is built for the settings where it is needed most, and it gives researchers a practical way to find the people who should be the focus of future studies and trials,” said Dr Eduwin Pakpahan, from Northumbria University's Applied Statistics and Data Science Research Group. The study is published in the American Journal of Epidemiology.

What Are The Five Factors Used To Predict Dementia Risk?

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The model can be applied using information gathered through a straightforward conversation with an older adult and, where relevant, a family member or carer. It does not require blood tests, brain scans or specialist equipment.

The five factors included in the risk score are:

• Age: The strongest single predictor. Dementia risk rises meaningfully from age 70 and more steeply from 80 onwards.
• Social engagement: This includes whether a person is married or living with others, how often they meet friends or family, and whether they participate in community or religious groups.
• Physical activity: The model considers how active a person is in daily life, across both work and leisure. Everyday movement, such as farming, walking to the market or doing household tasks, also counts.
• High blood pressure: Uncontrolled hypertension can damage the blood vessels supplying the brain over time. It is common, often undiagnosed in lower-income settings, and inexpensive to manage.
• Difficulty managing money: A family member or carer is asked whether the person has experienced a noticeable change in their ability to handle finances. This can be one of the early everyday signs of cognitive change.

How Does The Dementia Risk Score Work?

Each factor contributes points towards a total score ranging from 0 to 9. A person scoring 0 has around a 1% chance of developing dementia within three years, while someone scoring 9 has a nearly 19% chance.

The researchers built and tested the model across seven sites in China, Cuba, the Dominican Republic, Puerto Rico, Venezuela, Mexico and Peru. It achieved a performance score of 0.75, above the 0.70 threshold generally regarded as clinically useful.

However, the researchers emphasise that the tool is primarily intended for research rather than routine screening of the general population. It could give researchers and clinical trial teams a practical, low-cost way to identify and recruit people at higher risk of dementia.

The team has also called for the model to be validated in regions not covered by the study, particularly South Asia, the Middle East and North Africa, and Sub-Saharan Africa.

Read More: Dementia Is More Than Forgotten Birthdays, Lost Keys: Doctors Explain Early Signs Before Memory Loss

Why Is A Dementia Risk Prediction Tool Important?

Dementia affects more than 57 million people worldwide, with around 60% of cases occurring in LMICs across Latin America, the Caribbean, Asia and Africa.

Identifying people at higher risk could help researchers in these regions plan studies and clinical trials that better reflect their populations. A simple tool based on everyday information may also make risk assessment more accessible in settings where specialised diagnostic resources are limited.