Author Archives: support

Research finds association between food preservatives and type 2 diabetes risk

Higher intake of food preservatives, commonly used in industrially processed foods and drinks to prolong shelf life, has been associated with an increased risk of developing type 2 diabetes. This conclusion comes from a large-scale study conducted by researchers affiliated with several French research institutions, working within the Nutritional Epidemiology Research Team. Their findings draw on extensive health and dietary data collected from over 100,000 adults enrolled in the NutriNet-Santé cohort and were published in the journal Nature Communications.

Preservatives are part of the broader family of food additives and are now deeply embedded in the global food system. Their use has expanded alongside the growth of ultra-processed foods, which rely on additives to maintain freshness, texture, and safety during extended storage and transport. Data from the Open Food Facts World database indicate that, out of approximately three and a half million food and beverage products listed in 2024, more than 700,000 contained at least one preservative, underlining the scale of population exposure.

In their analysis, the researchers categorised preservative additives into two main groups. The first includes non-antioxidant preservatives, which prevent microbial growth or slow chemical reactions that cause spoilage. The second group consists of antioxidant additives, which delay deterioration by reducing or limiting oxygen exposure in food packaging. On ingredient labels, these substances are typically identified by European E-numbers, ranging from E200 to E299 for preservatives in the strict sense and from E300 to E399 for antioxidant additives.

Previous experimental research has raised concerns about the biological effects of some preservatives, suggesting they may damage cells or DNA and disrupt metabolic processes. However, until now, population-based evidence linking preservative exposure to type 2 diabetes has been limited. To address this gap, the research team examined long-term associations between dietary exposure to preservatives and the onset of type 2 diabetes within a large and well-characterised cohort.

Participants in the NutriNet-Santé study provided detailed information between 2009 and 2023, including medical history, socio-demographic background, lifestyle habits, and physical activity levels. They also regularly completed comprehensive 24-hour dietary records, specifying the names and brands of industrial food products consumed. These records were matched with several databases and laboratory measurements to estimate individual exposure to preservatives over time with a high level of precision.

During the follow-up period, 1,131 cases of type 2 diabetes were identified among 108,723 participants. After accounting for numerous potential confounding factors such as smoking, alcohol intake, and overall dietary quality, the analyses revealed clear associations. Higher overall consumption of preservative additives was linked to a 47% increase in type 2 diabetes incidence. Similar associations were observed for non-antioxidant preservatives and antioxidant additives, which were linked to 49% and 40% higher risks, respectively, compared with the lowest levels of consumption.

More information: Anaïs Hasenböhler et al, Associations between preservative food additives and type 2 diabetes incidence in the NutriNet-Santé prospective cohort, Nature Communications. DOI: 10.1038/s41467-025-67360-w

Journal information: Nature Communications Provided by INSERM (Institut national de la santé et de la recherche médicale)

Back Pain in Men Over 65 Tied to Poorer Sleep Years Down the Line, Study Finds

Leave a Reply

About half of older men experience sleep problems, back pain, or both, according to Soomi Lee, an associate professor of human development and family studies at Penn State. In a recent study, Lee and her colleagues set out to determine whether one of these common problems tends to come before the other. Their findings suggest that back pain can predict the development of sleep problems several years later in men aged 65 and older.

“Back pain and sleep disturbances are both serious concerns for older adults,” Lee explained. “By analysing data collected over a long period, we wanted to understand whether poor sleep leads to back pain, or whether back pain leads to poor sleep. What we found was that back pain tends to come first.”

The study, published in Innovation and Aging, drew on data from the Osteoporotic Fractures in Men Study, which followed 1,055 older men over several years. Participants completed two in-depth clinical sleep assessments at least six years apart. Between these visits, they regularly reported their back pain by mail every four months, rating both how often the pain occurred and how severe it was.

Sleep problems were defined broadly and included irregular sleep patterns, short sleep duration, daytime sleepiness, and dissatisfaction with sleep quality. For each participant, the researchers summarised back pain reports over one year to create overall scores for pain frequency and severity. These scores were then compared with sleep problem scores from the clinical visits.

The researchers first examined whether early sleep problems were linked to later back pain. They then reversed the analysis to see whether earlier back pain predicted sleep issues measured six years later. This second approach revealed a clear pattern: back pain was associated with a 12% to 25% increase in sleep problems years down the line. In contrast, sleep problems did not appear to increase the risk of developing back pain in the future.

Men who reported back pain were more likely to fall asleep either too early or too late and were more dissatisfied with the quality of their sleep overall. According to Lee, this has important implications for families, caregivers, and clinicians. “If loved ones notice back pain in an older adult, it can serve as a warning sign,” she said. “Acknowledging and addressing back pain early may help prevent later sleep problems and the additional health issues linked to poor sleep.”

These associated health concerns include memory difficulties, depression, anxiety, and an increased risk of falls. Lee emphasised that the study focused only on men and that further research is needed to determine whether the same patterns hold for women and for people of colour, who were underrepresented in the sample. Even so, she stressed that anyone experiencing persistent back pain should discuss appropriate management options with a healthcare professional.

“Now that we know back pain tends to precede sleep problems, it’s clearer that effective pain management may play an important role in maintaining good sleep and protecting overall health in older adults over time,” Lee said.

More information: Soomi Lee et al, Back pain precedes sleep problems in older men, Innovation in Aging. DOI: 10.1093/geroni/igaf113

Journal information: Innovation in Aging Provided by Penn State

Older Adults Under Stress Face Greater Challenges Recovering from Surgery

Leave a Reply

Even relatively modest stress before surgery may significantly affect how well older adults recover, according to new research from Duke University School of Medicine. The study suggests that psychological strain is not simply an emotional side effect of preparing for surgery, but a factor that can meaningfully influence physical recovery and post-operative wellbeing in later life.

The research found that older adults who entered the operating room carrying a greater number of worries faced higher risks of complications after surgery. These patients were more likely to experience delirium, report inadequately controlled pain, and remain in hospital for extended periods. Importantly, these outcomes were observed even among individuals who did not describe themselves as highly stressed, indicating that stress may exert its effects quietly and cumulatively rather than through overwhelming anxiety alone.

Senior author Leah C. Acker, an anaesthesiologist at Duke Health, said the findings point to a missed opportunity in pre-surgical care. Stress is rarely measured in a structured way before operations, yet it may be a modifiable risk factor. Identifying and addressing stress early, she noted, could help clinicians reduce complications and improve recovery trajectories for older patients.

The study focused on adults preparing for major surgery, excluding heart and brain procedures. More than 40 per cent of participants reported moderate to high distress in the lead-up to their operations — levels comparable to those seen in patients with advanced cancer. This finding highlights how demanding the pre-operative period can be for older adults, even when surgery is planned and medically routine.

One of the most striking results was that recovery outcomes were tied more closely to the number of stressors a patient faced rather than how intense those stressors felt. Each additional worry increased the odds of delirium by 19 per cent, while higher stress counts were also strongly associated with increased pain and more extended hospital stays. Acker described this pattern as an “overwhelmed phenotype”, in which multiple small pressures accumulate and interfere with the body’s ability to heal effectively.

To assess stress, researchers used a brief digital version of the NCCN Distress Thermometer with 132 patients between late 2022 and early 2024. Common concerns included sleep or appetite changes, communication with healthcare providers, and family responsibilities, alongside broader worries about finances, home maintenance, loss of independence, and maintaining meaningful activities. Because most adults over 65 will undergo surgery at least once, Acker emphasised the need for better tools to identify those at risk — particularly for delirium, a serious post-operative complication that increases hospital costs and long-term risk of dementia.

More information: Leah C. Acker et al, Mixed-methods Analysis of Preoperative Distress and Postoperative Outcomes in a Prospective, Observational Cohort of Older Adults, Anesthesiology. DOI: 10.1097/ALN.0000000000005780

Journal information: Anesthesiology Provided by Duke University

Concerns grow over faster ageing and dementia risk in survivors of childhood and young adult cancers

Leave a Reply

Adolescents and young adults who survive cancer show signs of ageing more rapidly than peers who have never had the disease, according to new research that points to changes in both cellular biology and brain function. The study suggests that accelerated ageing is not confined to the body alone but also affects cognitive abilities such as memory, attention, and the speed at which information is processed. These findings add to growing concern about the long-term health consequences faced by people treated for cancer early in life.

The research was recently published in Nature Communications. It was led by AnnaLynn Williams, PhD, an investigator at the University of Rochester Wilmot Cancer Institute, with Kevin Krull, PhD, of St. Jude Children’s Research Hospital serving as co-corresponding author. Together, the team examined how cancer and its treatments influence biological ageing in people diagnosed during childhood, adolescence, or young adulthood.

While the results highlight significant risks, the researchers also point to encouraging possibilities. Ongoing work at Wilmot suggests that accelerated ageing may be modifiable rather than permanent. Williams noted that healthy lifestyle changes—including quitting smoking, exercising regularly, and improving nutrition—could help slow or even reverse some ageing-related effects. This raises the prospect that targeted interventions might meaningfully enhance long-term health and functioning for young adult cancer survivors.

Williams emphasised that survivors often have many decades of life ahead of them, making early intervention especially important. If accelerated ageing begins soon after treatment and alters long-term health trajectories, intervening early could not only extend lifespan but also improve quality of life. This approach reflects a broader shift in cancer care, which increasingly recognises survivorship as a distinct phase requiring sustained medical and psychosocial support.

For many survivors treated as children or young adults, these biological changes coincide with significant life transitions. Completing education, starting careers, establishing independence, and forming families can all be affected by subtle cognitive difficulties. Williams described this convergence as a “perfect storm”, noting that survivors often experience poorer educational and employment outcomes than their siblings, highlighting how health effects can ripple into social and economic life.

The study included roughly 1,400 participants who were at least five years beyond treatment, with some surviving for decades. Most had been treated for acute lymphoblastic leukaemia or Hodgkin lymphoma. Researchers found faster biological ageing across treatment types, though chemotherapy showed the strongest association. Crucially, higher biological age was linked to worse memory and attention. Ongoing studies now aim to identify when ageing acceleration begins and how interventions—such as exercise—might help reverse it.

More information: AnnaLynn Williams et al, Epigenetic age acceleration, telomere length, and neurocognitive function in long-term survivors of childhood cancer, Nature Communications. DOI: 10.1038/s41467-025-65664-5

Journal information: Nature Communications Provided by University of Rochester Medical Center

Researchers uncover links between infection and ageing through cellular senescence mechanisms

Leave a Reply

A meeting report published on 23 December 2025 in Aging-US (Volume 17, Issue 12) brings together the main scientific discussions from the 10th International Cell Senescence Association conference, held in Rome in September 2025. Led by Stefanie Deinhardt-Emmer of Jena University Hospital and Marco De Andrea of the University of Piemonte Orientale and the University of Turin, the report, titled “Cellular senescence meets infection”, reflects a growing shift in how researchers understand the long-term biological consequences of infectious disease.

At the centre of the report is cellular senescence, a state in which cells permanently stop dividing and begin releasing inflammatory and tissue-altering signals. Traditionally associated with ageing and cancer, senescence is now gaining attention for its role in infection biology. The authors emphasise that this link is vital because it connects acute and chronic infections with long-lasting inflammation, tissue damage, and age-related decline, helping to explain why some infections have effects that persist long after pathogens are cleared.

A key concept discussed throughout the meeting was infection-driven senescence (IDS). Researchers described how viruses and bacteria can trigger senescence in infected cells and spread their effects to neighbouring tissues through inflammatory signalling. While this response may initially help limit pathogen replication, it can also prolong inflammation and impair recovery. These outcomes are particularly relevant in older adults and in individuals experiencing chronic or recurrent infections.

Respiratory infections were a major focus of the conference. Several sessions explored how influenza viruses and SARS-CoV-2 induce senescence in lung epithelial cells, contributing to sustained inflammation and reduced tissue repair. Experimental models showed that lowering the number of senescent cells improved lung healing even after viral clearance, offering a potential explanation for persistent respiratory symptoms observed in some patients following viral infection.

Chronic viral infections were also highlighted as important drivers of senescence. Evidence was presented showing that human cytomegalovirus and HIV promote senescence in immune and vascular cells. In people living with HIV, viral proteins were linked to biological changes resembling accelerated ageing, despite effective antiviral therapy. These findings help clarify why age-related conditions often appear earlier and more frequently in this population.

Notably, the report shows that infection-induced senescence is not limited to viruses. Researchers described how the bacterium Mycobacterium abscessus induces senescence in immune cells during chronic infection, increasing inflammation and susceptibility to further disease. Across the conference, speakers discussed emerging therapies aimed at removing senescent cells or reducing their harmful inflammatory signals. Together, these discussions present IDS as a unifying framework linking infection, immunity, and ageing, with significant implications for understanding chronic disease and long-term health after infection.

More information: Stefanie Deinhardt-Emmer et al, Cellular senescence meets infection: highlights from the 10th annual International Cell Senescence Association (ICSA) conference, Rome 2025, Aging-US. DOI: 10.18632/aging.206349

Journal information: Aging-US Provided by Impact Journals LLC

Study finds possible connection between brain injuries and suicide risk

Leave a Reply

Adults who sustain a head injury face a markedly increased risk of attempting suicide compared with those who have not experienced such injuries, according to a major new study conducted in the UK. The research provides some of the most comprehensive evidence to date that head injuries are associated not only with physical harm, but also with longer-term psychological vulnerability.

The study, published in Neurology, the medical journal of the American Academy of Neurology, was led by researchers at the University of Birmingham. It represents the first population-wide investigation to examine suicide risk across all forms of head injury in the general adult population, rather than focusing narrowly on traumatic brain injuries within military, sporting, or hospital-based groups. By taking this broader approach, the researchers aimed to capture risks that may previously have been underestimated or overlooked.

To achieve this, the team carried out an extensive population-based matched cohort study using nationally representative electronic primary healthcare records from more than 1.8 million adults. These records were linked with Hospital Episode Statistics and data from the Office for National Statistics, allowing the researchers to follow participants’ health outcomes over a period of up to 20 years. This extended follow-up and extensive data linkage provided a robust foundation for analysing patterns of suicide attempts following head injury.

The findings showed that adults with a history of head injury were 21 per cent more likely to attempt suicide than those without such injuries, even after accounting for factors such as age, sex, socioeconomic deprivation, and previous mental health conditions. In practical terms, the incidence rate of suicide attempts was 2.4 per 1,000 person-years among people with head injuries, compared with 1.6 per 1,000 person-years in the matched control group. While the absolute increase in risk was modest, the consistency of the association across a huge population highlights its clinical and public health significance.

Notably, the elevated risk was observed across all subgroups studied, including individuals with no recorded history of mental health conditions. This suggests that head injuries themselves may contribute to psychological distress or vulnerability, independent of pre-existing mental illness. The researchers also found that the risk of suicide attempts was highest during the first 12 months following a head injury, indicating a critical period during which individuals may be particularly in need of monitoring and support.

Professor Nicola Adderley, Professor of Epidemiology and Real-World Evidence at the University of Birmingham and a lead author of the study, emphasised that the consequences of head injuries extend beyond immediate physical symptoms. She noted that such injuries can have profound psychological effects. She argued that suicide risk assessments should be considered for anyone who has recently sustained a head injury, regardless of their prior mental health history, to improve patient safety and outcomes.

Although suicide attempts were more frequent among people with head injuries, the study did not identify a significant increase in deaths by suicide once other competing risks were taken into account. This finding suggests that head injuries may be associated with a higher likelihood of non-fatal attempts rather than an increase in suicide mortality. Nonetheless, given that nearly 6,000 deaths each year in the UK are attributed to suicide and that attempts are far more common, the implications remain serious.

The authors argue that their findings have clear implications for both clinical practice and health policy. They call for routine suicide risk screening in primary and secondary care for patients with head injuries, enhanced mental health support during the first year after injury, and greater public awareness to help families and caregivers recognise warning signs. Further research is also needed to develop and test targeted suicide prevention strategies for people with head injuries, particularly during this high-risk early period.

More information: Tiffany E. Gooden et al, The Risk of Suicide Attempts After Head Injury
A Matched UK Population–Based Cohort Study, Neurology. DOI: 10.1212/WNL.0000000000214474

Journal information: Neurology Provided by University of Birmingham

Nearly 1.6 Million Adults in the UK Turned to Weight Loss Drugs Last Year

Leave a Reply

An estimated 1.6 million adults in England, Wales and Scotland used prescription weight loss drugs such as Wegovy and Mounjaro between early 2024 and early 2025, according to new research led by University College London. The study, published in BMC Medicine and funded by Cancer Research UK, also found substantial unmet demand, with a further 3.3 million people saying they would consider using weight loss medication over the next year.

Researchers analysed survey responses from 5,260 adults who were representative of the general population and who took part in early 2025. Overall, 4.5% reported using one of the medications in the past year for any reason, while 2.9% said they used them specifically for weight loss, equating to around 1.6 million people. A smaller group—1.7%, or roughly 910,000 adults—reported using the drugs exclusively for weight loss, without another reason such as managing type 2 diabetes or reducing cardiovascular risk.

Use of weight loss medication was not evenly distributed across the population. The researchers found it was about twice as common among women as men and most prevalent among those aged 45 to 55. Higher use was also reported by people who experienced moderate or severe psychological distress in the month before the survey. While overall usage rates were similar across social grades, interest in future use was notably higher among more disadvantaged groups, where obesity rates tend to be greater, suggesting that private prescribing may not be meeting demand.

Taken together, the findings suggest that nearly 4.9 million adults in Great Britain—almost one in ten—have either recently used a weight loss drug or are interested in doing so soon. Lead author Professor Sarah Jackson noted that this level of use and interest far exceeds NHS England’s original target of prescribing these medications to 220,000 people over three years. However, the study could not assess whether use reflected genuine medical need, as respondents’ body mass index and health conditions were not recorded.

The research also highlighted safety and equity concerns. Among those using medication for weight loss, around 15% reported taking drugs not licensed in the UK for that purpose, such as Rybelsus, which is approved only for type 2 diabetes. Using medicines “off-label”, particularly without clinical supervision, may increase health risks. The authors stressed that NHS prescribing data captures only a small proportion of overall use, as many people appear to be accessing these drugs privately.

Interest in future use was reported by 6.5% of respondents who had not taken weight loss medication in the past year, with higher interest among women, people aged 45 to 55, and those experiencing psychological distress. Commenting on the findings, Cancer Research UK said that while these drugs can support weight loss, they are not a cure-all and many people regain weight after stopping treatment. The charity emphasised the need for further research, careful medical oversight, and broader action to create healthier environments that support long-term weight management.

More information: Sarah Jackson et al, Prevalence of use and interest in using glucagon-like peptide-1 receptor agonists for weight loss: a population study in Great Britain, BMC Medicine. DOI: 10.1186/s12916-025-04528-7

Journal information: BMC Medicine Provided by University College London

Targeting senescent brain cells may offer new ways to ease epilepsy symptoms

Leave a Reply

Temporal lobe epilepsy (TLE) is a common and often severe form of epilepsy characterised by recurrent seizures and problems with memory and thinking. Increasing evidence suggests that this condition is linked to the premature ageing of brain cells. A new study from researchers at Georgetown University Medical Center provides compelling evidence that targeting these ageing, or senescent, cells may reduce seizures and improve cognitive function, at least in animal models.

The NIH-funded study, published on 22 December in Annals of Neurology, examined both human brain tissue and a well-established mouse model of TLE. The researchers focused on senescent glial cells, which are support cells that help maintain and protect neurons but do not generate electrical signals themselves. Although glial cells are essential for healthy brain function, when they become senescent, they can contribute to inflammation and tissue dysfunction.

In laboratory analyses of donated human brain tissue, the team examined samples surgically removed from the temporal lobes of people with TLE and compared them with tissue obtained during autopsies from individuals without epilepsy. They found a striking five-fold increase in senescent glial cells in the TLE samples. This suggested that cellular ageing might play a direct role in the development or persistence of seizures in this condition.

Building on these findings, the researchers studied mice that had experienced a brain injury known to trigger TLE. Within just two weeks of the injury, the mice showed clear increases in markers of cellular senescence at both the genetic and protein levels. When the investigators used either genetic techniques or drug treatment to remove senescent cells, the results were notable. Levels of ageing cells were reduced by around 50%, seizure frequency decreased, and the animals’ performance on memory-based maze tests returned to normal. Importantly, about one-third of the treated mice were protected from developing epilepsy altogether.

The drug treatment used in the study combined dasatinib and quercetin. Dasatinib is an FDA-approved targeted therapy used in certain forms of leukaemia. At the same time, quercetin is a naturally occurring plant compound found in foods such as fruits, vegetables, tea, and wine. Together, these compounds have been widely used in animal studies to eliminate senescent cells selectively. Because dasatinib already has a known safety profile in humans and both drugs are being tested in early-stage clinical trials for other conditions, the researchers believe this approach could move more quickly towards human studies.

Senior author Patrick A. Forcelli emphasises the clinical importance of these findings, noting that roughly one-third of people with epilepsy do not achieve seizure control with existing medications. He suggests that senotherapy, which aims to remove senescent cells, could one day reduce the need for invasive brain surgery or improve outcomes for patients who do undergo surgical treatment.

The study also highlights broader implications beyond epilepsy. Senescent glial cells have recently been linked to ageing and neurodegenerative disorders such as Alzheimer’s disease, an area the research team continues to investigate. Ongoing work is exploring additional drugs that target cellular senescence, as well as identifying the most effective time windows for intervention. The researchers hope these efforts will ultimately lead to safer, more effective treatments for people living with epilepsy.

More information: Tahiyana Khan et al, Senescent Cell Clearance Ameliorates Temporal Lobe Epilepsy and Associated Spatial Memory Deficits in Mice, Annals of Neurology. DOI: 10.1002/ana.78118

Journal information: Annals of Neurology Provided by Georgetown University Medical Center

Do circadian rhythms play a role in dementia risk?

Leave a Reply

Circadian rhythms that are weaker, more fragmented, or that peak later in the day are associated with a higher risk of dementia, according to a study published on 29 December 2025 in Neurology, the medical journal of the American Academy of Neurology. The researchers found that people whose daily activity patterns were less clearly defined, or whose activity levels peaked later rather than earlier in the afternoon, were more likely to develop dementia over time. Notably, the findings show an association rather than proof that disrupted circadian rhythms directly cause dementia.

Circadian rhythms are the body’s internal timekeeping system. They regulate the 24-hour sleep–wake cycle and influence many other processes, including hormone release, digestion, and body temperature. The brain controls these rhythms and is strongly affected by exposure to light. When circadian rhythms are strong, the body clock stays closely aligned with the natural day–night cycle, producing clear and consistent signals that help regulate daily activity and rest.

People with robust circadian rhythms tend to keep relatively stable sleep and activity schedules, even when their routine changes slightly or the seasons shift. In contrast, weaker circadian rhythms are more easily disrupted by changes in light exposure or daily schedules. Individuals with weaker rhythms are more likely to experience shifts in their sleep and activity patterns, which may place additional strain on the body over time.

“Changes in circadian rhythms occur with ageing, and growing evidence suggests that circadian disruption may be a risk factor for neurodegenerative diseases such as dementia,” said study author Wendy Wang, MPH, PhD, of the Peter O’Donnell Jr. School of Public Health at UT Southwestern Medical Center. She explained that the study directly measured rest–activity patterns and found that participants with weaker, more fragmented rhythms, as well as those whose activity peaked later in the day, had an elevated risk of developing dementia.

The study followed 2,183 adults with an average age of 79 who did not have dementia at the beginning of the research. About 24% of participants were Black, and 76% were white. Each participant wore a small heart monitor attached to the chest for around 12 days, allowing researchers to measure periods of activity and rest continuously. Participants were then followed for an average of three years, during which time 176 people were diagnosed with dementia.

Researchers analysed several measures of circadian rhythm strength, including relative amplitude, which reflects the contrast between a person’s most active and least active periods. Higher relative amplitude indicates a stronger circadian rhythm. When participants were divided into groups, those with the weakest rhythms had nearly 2.5 times the risk of dementia compared with those with the strongest rhythms, even after accounting for factors such as age, blood pressure, and heart disease.

The study also found that people whose activity peaked later in the afternoon, from around 2:15 p.m. onwards, had a 45% higher risk of dementia than those whose activity peaked earlier. A later activity peak may indicate a mismatch between the body’s internal clock and environmental cues like daylight and darkness.

The researchers noted that circadian disruption may affect inflammation, sleep quality, and the brain’s ability to clear amyloid, a protein linked to dementia. However, a limitation of the study was the lack of data on sleep disorders, such as sleep apnoea, which could also influence dementia risk.

More information: Wendy Wang et al, Association Between Circadian Rest-Activity Rhythms and Incident Dementia in Older Adults The Atherosclerosis Risk in Communities Study, Neurology. DOI: 10.1212/WNL.0000000000214513

Journal information: Neurology Provided by American Academy of Neurology

Keep moving, live longer: Light activity associated with improved survival in diabetes, heart and kidney disease

Leave a Reply

Light-intensity activities such as walking, gardening or household chores were associated with a lower risk of death among people with cardiovascular-kidney-metabolic (CKM) syndrome, according to new research published in the Journal of the American Heart Association. The findings suggest that even modest levels of movement may offer meaningful health benefits, particularly for people living with more advanced stages of this complex condition.

CKM syndrome is common, affecting nearly nine in ten adults in the United States, and includes a combination of risk factors such as high blood pressure, unhealthy cholesterol and lipid levels, elevated blood glucose, excess body weight and impaired kidney function. While each of these factors is harmful on its own, their combination substantially increases the likelihood of serious outcomes such as heart attack, stroke and heart failure. CKM syndrome is classified into stages from 0 to 4, with higher stages indicating more severe disease and greater cardiovascular risk.

The study highlights that light physical activity is the most common form of movement among adults and may be more achievable than moderate- or vigorous-intensity exercise for people with chronic illness. While standard physical activity guidelines often emphasise higher-intensity exercise, this level of exertion may not be realistic or safe for individuals with advanced CKM syndrome. As a result, identifying benefits from lighter activities is especially important for this population.

Researchers analysed data from around 7,200 adults who participated in the National Health and Nutrition Examination Survey between 2003 and 2006. Participants’ health status was assessed using physical examinations and blood tests, while activity levels were measured objectively using accelerometers worn for up to seven days. These devices allowed researchers to distinguish between light, moderate and vigorous activity. Light physical activity was defined as movement that does not significantly increase breathing rate, such as casual walking, stretching, yoga or everyday household tasks.

When participants were grouped by CKM stage, the researchers found a clear pattern. Greater time spent in light physical activity was linked to a significantly lower risk of death among individuals in CKM stages 2, 3 and 4. On average, each additional hour of light activity per day was associated with a 14% to 20% reduction in the risk of death over a follow-up period of roughly 14 years. Notably, the benefits appeared to increase with disease severity. For example, increasing daily light activity from 90 minutes to two hours was linked to a larger reduction in risk for people in stage 4 than for those in stage 2.

Light physical activity is an under-recognised but potentially powerful tool for improving heart health in people with CKM syndrome. For individuals who are unable to meet conventional exercise recommendations, small increases in everyday movement may translate into substantial long-term benefits.

Independent experts welcomed the findings, noting that light-intensity activity remains an under-studied area despite being the most accessible form of movement for many people. Such activities support circulation, energy use and general mobility, all of which contribute to better health.

The researchers caution that the study was observational, meaning it can identify associations but cannot prove cause and effect. It is possible that people with more severe illness were both less active and at higher risk of death. Even so, the results strengthen the case for encouraging gentle, achievable movement as part of a broader approach to managing CKM syndrome.

More information: Joseph Sartini et al, Light Physical Activity and All‐Cause Mortality in US Adults Across Cardiovascular‐Kidney‐Metabolic Syndrome Stages, Journal of the American Heart Association. DOI: 10.1161/JAHA.125.046271

Journal information: Journal of the American Heart Association Provided by American Heart Association

New research challenges established models of Parkinson’s disease

Leave a Reply

A new study led by researchers at McGill University is challenging a long-standing theory about how dopamine supports movement, offering insights that could reshape scientific thinking about treatments for Parkinson’s disease. By re-examining dopamine’s fundamental role in motor control, the findings suggest a more straightforward and potentially more effective way of understanding why current therapies work, and how future treatments might be designed.

Published in Nature Neuroscience, the research shows that dopamine does not directly determine the speed or force of individual movements, as has been widely assumed. Instead, it provides a crucial background condition that allows movement to occur at all. Rather than acting as a moment-by-moment controller of motion, dopamine functions more like a stabilising system that keeps the brain’s motor circuits ready and able to operate.

Senior author Nicolas Tritsch, an Assistant Professor in McGill’s Department of Psychiatry and a researcher at the Douglas Research Centre, explains that these results call for a fundamental rethink. According to Tritsch, restoring dopamine to a healthy baseline level may be sufficient to improve movement in people with Parkinson’s disease, without needing to recreate complex dopamine signals precisely. This reframing could simplify how researchers and clinicians approach treatment strategies.

Dopamine has long been associated with what scientists call motor vigour — the capacity to move with adequate speed, strength and fluidity. In Parkinson’s disease, dopamine-producing neurons gradually degenerate, leading to hallmark symptoms such as slowness of movement, tremors, stiffness and impaired balance. For decades, researchers have sought to understand precisely how dopamine loss translates into these motor difficulties.

The most common treatment, levodopa, is highly effective at improving movement, yet its precise mechanism has remained unclear. In recent years, sophisticated measurement techniques revealed brief, rapid bursts of dopamine release during movement. These discoveries led many scientists to conclude that such fast dopamine spikes directly control how vigorous each movement is. This interpretation has strongly influenced current theories of motor control.

The new study, however, points in a different direction. Tritsch likens dopamine’s role not to a throttle that sets movement speed, but to engine oil in a car. Without it, the system cannot function properly, but it does not dictate how fast the engine runs at any given moment. This analogy captures the idea that dopamine is essential for enabling movement, rather than fine-tuning each action as it unfolds.

To test this hypothesis, the researchers measured brain activity in mice as the animals pressed a weighted lever. Using a light-based technique, they were able to switch dopamine-producing neurons on or off with precise timing. If brief dopamine bursts were truly responsible for controlling movement vigour, altering dopamine levels at the moment of action should have changed how forcefully or quickly the mice moved. Instead, the researchers observed no such effect.

Further experiments with levodopa revealed that the drug improved movement by increasing the brain’s overall, or baseline, dopamine level rather than by restoring fast dopamine bursts. This finding provides a more straightforward explanation for why levodopa works so well, despite not precisely replicating natural dopamine signalling patterns.

The implications are significant. More than 110,000 Canadians currently live with Parkinson’s disease, and this number is expected to more than double by 2050 as the population ages. A better understanding of dopamine’s proper role opens the door to therapies focused on maintaining stable baseline dopamine levels. It also encourages a reassessment of older treatments, such as dopamine receptor agonists, which showed promise but caused side effects because they acted too broadly across the brain. With this new framework, scientists may be able to design more targeted and safer therapies in the future.

More information: Haixin Liu et al, Subsecond dopamine fluctuations do not specify the vigor of ongoing actions, Nature Genetics. DOI: 10.1038/s41593-025-02102-1

Journal information: Nature Genetics Provided by McGill University

In what ways does stroke impair speech understanding?

Leave a Reply

After a stroke, some individuals develop a language disorder that disrupts how their brains handle the sounds of speech. While their hearing itself may remain intact, the neurological processes that allow speech sounds to be interpreted as meaningful language can be compromised. To better understand how stroke alters these processes, a team of researchers examined changes in brain activity associated with speech comprehension, focusing on how the injured brain differs from a healthy one during everyday listening.

The study was led by Laura Gwilliams, a faculty scholar at the Wu Tsai Neuroscience Institute and Stanford Data Science, and an assistant professor at the Stanford School of Humanities and Sciences, together with Maaike Vandermosten, an associate professor in the Department of Neurosciences at KU Leuven. Their work compared the brain activity of 39 people who had experienced a stroke with that of 24 healthy adults of a similar age. By analysing these two groups side by side, the researchers aimed to uncover the neural mechanisms that support language processing and how these mechanisms are altered after stroke.

To capture brain activity in a naturalistic way, participants were asked to listen to a spoken story while their neural responses were recorded. This approach allowed the researchers to observe how the brain processes speech in real time, rather than relying on artificial tasks involving isolated sounds or words. The results revealed a striking pattern. Individuals with stroke-related difficulties in verbal speech processing were not slower than healthy listeners in responding to speech sounds. Instead, their brain responses were noticeably weaker.

This finding suggests that the core problem is not a delay in processing but a reduction in the strength or quality of that processing. In practical terms, people affected by this language disorder appear to detect sounds just as efficiently as those without brain injury. However, they struggle when it comes to combining these sounds into coherent linguistic units that carry meaning. The brain receives the auditory information, but the integration needed to understand spoken language is less effective.

The study also highlighted differences in how the brain deals with uncertainty in speech. When words were difficult to hear or ambiguous, healthy participants showed prolonged processing of speech sound features. This extended neural activity is thought to reflect the brain’s effort to resolve uncertainty and arrive at the correct interpretation. In contrast, people who had experienced a stroke showed less sustained processing in these situations. This shortened engagement with speech sounds may make it harder for them to identify words that are unclear or masked by noise successfully.

Taken together, these findings point to specific patterns of brain activity that are crucial for understanding spoken language. They suggest that successful speech comprehension relies not only on detecting sounds quickly but also on maintaining and strengthening neural processing when interpretation becomes challenging. After a stroke, this supportive processing may be reduced, contributing to persistent language difficulties.

The authors emphasise that these insights could have important clinical implications. First author Jill Kries expressed enthusiasm about continuing this line of research, particularly the use of simple, natural listening tasks such as hearing a story. Such approaches may improve the diagnosis of language processing disorders, which currently often require lengthy and demanding behavioural assessments. By focusing on how the brain responds during everyday listening, future tools could become both more efficient and more closely aligned with real-world communication challenges.

More information: Jill Kries et al, The spatio-temporal dynamics of phoneme encoding in aging and aphasia, JNeurosci. DOI: 10.1523/JNEUROSCI.1001-25.2025

Journal information: JNeurosci Provided by Society for Neuroscience