It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Tuesday, February 03, 2026
Everyday diabetes medicine could treat common cause of blindness
Doctors have found that metformin, an everyday medicine for diabetes, is associated with less progression of age-related macular degeneration (AMD), the commonest cause of blindness in western countries.
People with diabetes over the age of 55 years taking metformin were 37% less likely to develop the intermediate stage of AMD over a five year period compared to those not taking metformin.
AMD is a disease which affects the central retina or macular at the back of the eye. It eventually causes the light-sensitive tissue to die off (geographic atrophy, a form of ‘dry’ AMD) or be damaged by abnormal blood vessel growth (‘wet’ AMD). Intermediate and advanced AMD affects 10-15% of people over 65 years of age (1.1 to 1.8 million people in the UK), and is the commonest cause of blindness in high-income countries.
The annual cost of AMD is estimated to be £11.1billion in the UK. Geographic atrophy has no treatment in the UK and Europe, while treatments for wet AMD are expensive and unpleasant (repeated injections into the eye).
The research from the University of Liverpool used pictures taken of the eyes of 2,000 people attending the routine diabetic eye disease screening programme in Liverpool over 5 years. The researchers assessed whether AMD was present on the photographs and how severe it was, and then compared those taking metformin and those who were not. They also adjusted for factors which might bias the result such as age, sex, and duration of diabetes. The odds of developing intermediate AMD over 5 years in the metformin group was 0.63 compared to the no metformin group (95% confidence range 0.43 to 0.92).
A potential benefit from metformin in AMD has been suspected before, but this is the first study to grade AMD from eye photographs. Previous studies on metformin have used secondary information on AMD such as GP diagnostic codes, or insurance claims in the US.
Dr Nick Beare, an eye doctor who led this research, says: “Most people who suffer from AMD have no treatment, so this is a great breakthrough in our search for new treatments. What we need to do now is test metformin as a treatment for AMD in a clinical trial. Metformin has the potential to save many people’s sight.”
Metformin taken as a tablet, is the first line treatment for type 2 or adult-onset diabetes. It reduces the production of sugar (glucose) in the liver along with other effects which benefit diabetes. Metformin also has anti-aging effects including being antioxidant, anti-inflammatory and stimulating house-keeping functions and energy production in cells (pro-mitochondria). Metformin is an off-patent medicine and is cheap (about £50/patient/year in the NHS). Side-effects include initial nausea and diarrhoea, and rarely kidney damage in people who are dehydrated.
AMD in Society
Dame Judi Dench, Sir John Mills, Stephen King, Roseanne Barr and June Brown (Dot Cotton) have all publicly acknowledged sight loss due to AMD. Edgar Degas, the impressionist painter, is thought to have suffered from AMD which affected his style of painting in later years.
Journal
BMJ Open
Subject of Research
People
Are cats ‘vegan’ meat eaters? Study finds why isotopic fingerprint of cat fur could trick us into thinking that way
Cats process proteins so efficiently that isotope signatures in their hair resemble plant-eaters, indicating that isotopic values alone may be insufficient to determine what animals ate
Cats – unlike humans – are true carnivores: they must eat meat to survive because their bodies can’t draw some essential nutrients from plants. By looking at tissues, researchers can get a good understanding of what foods animals ate.
Now, researchers at the Department of Microbiology and Ecosystem Science at the University of Vienna measured nitrogen and its stable isotopes 15N and 14N in the fur and whiskers of domestic cats as well as in cat food available in supermarkets. They then compared nitrogen isotope values to those found in the hair of humans who ate different diets. The results were published in Frontiers in Ecology and Evolution.
“When we tested cats’ hair for nitrogen isotopes, the results made them look like they eat mostly plants,” said first co-author Viktoria Zechner. “This means that looking isotopically at animal hair alone can sometimes be misleading about their diet.”
From food to fur
Nitrogen has two main stable isotopes, 14N (lighter) and 15N (heavier). The ratio between them is expressed by δ15N. It can be used to determine an animal’s position in the food web, with higher δ¹⁵N values indicating a higher position. However, nitrogen isotope values in animals’ food and tissues usually aren’t identical. This difference is described by a number known as the trophic discrimination factor (TDF). A low TDF means the isotope signatures in an animal’s tissues are very similar to the isotope signatures of their food source. On average, animals show a TDF of around 3 to 5‰ (parts per thousand).
The team used hair from 35 domestic cats who were kept indoors and fed commercially available food. Whisker samples were taken from 14 cats. In a parallel study, human scalp hair from 653 people eating different diets was collected. The average isotopic value of all commercial cat foods included in the study was determined. For humans, the team determined isotopic values by diet: vegans, vegetarians, and omnivores, respectively. The team then compared isotope differences between the hair of cats and humans.
‘Vegan’ meat-eaters
In human hair, δ15N values differed significantly by diet: the omnivores’ value was around 8.8‰, displaying much higher δ15N signatures than vegetarians (around 8.2‰) and vegans (7.2‰). In cats’ hair and whiskers, δ15N values were closer to the values of vegans, lying at around 6.6‰ and 6.5‰, respectively. Average δ15N values of a mixed human diet lay at 4.1‰ and in cat food at around 5.0‰.
Therefore, when considering differences in 15N enrichment in human food and tissue and cat food and tissue, the researchers found a substantially lower TDF of around 1.6‰ in cats than in human omnivores (around 4.7‰).
“In this sense, the old saying ‘you are what you eat’ might apply to cats more than we thought,” said Maryna Tiutiunnyk, first co-author of the study. The reason for this unexpectedly low TDF could have to do with how cats’ bodies process nitrogen and its stable isotopes. Cats are efficient in using the proteins from their meat diet. “Because they eat high-quality meat protein that closely matches their own bodies’ amino acid makeup, they can channel those dietary amino acids straight into their hair protein (keratin) with only minimal isotopic changes,” Tiutiunnyk explained. Accordingly, their hair does not reflect many of the chemical and isotopic changes that a meat meal induces. Other animals and humans, both meat-eaters and vegans, process dietary protein far less efficiently, leading to higher nitrogen isotope enrichment in their hair.
Treacherous signatures
“This does not mean that cats eat like vegans,” first co-author Hannah Riedmüller pointed out. “But it overturns long-standing assumptions about carnivore isotope signatures.” It also means that low δ15N values are not always proof of a plant-based diet but can reflect other things such as diet composition or metabolism efficiency.
“It therefore is imperative to find valid proxies that can be measured relatively easily to define diet quality relative to organismal demand and body composition, to better predict trophic level enrichment,” senior author Dr Wolfgang Wanek explained.
Despite these findings, the physiological mechanisms underlying the low trophic 15N enrichment and therefore TDF in cats remain unknown. The study also focused exclusively on hair and whiskers, and it is yet to be determined if similarly low TDFs occur in other tissues that are frequently analyzed in isotopic studies, such as blood, muscles, or bones.
Nearly two million children in the UK are affected by early language delays. New research will examine whether noise in nurseries is a hidden factor.
An estimated 1.9 million children across the UK are affected by early language delays, with rates doubling among children from disadvantaged backgrounds. A major new research project led by The Institute for the Science of Early Years (ISEY) at the University of East London supported by the Nuffield Foundation, will explore how background noise in nurseries affects early language development. The study will also test whether simple, low-cost changes in nursery environments could significantly improve outcomes for young children, particularly those from disadvantaged backgrounds.
Children who struggle with early communication are eleven times more likely to fall behind in Maths by age 11, twice as likely to experience mental health difficulties, and twice as likely to be unemployed in adulthood.
At a time when changes to UK government funding are increasing the number of infants entering formal childcare, understanding how nursery environments can be better designed to support early development has never been more urgent.
This first-of-its-kind study will use wearable technology to explore how children’s communication is affected moment by moment by fluctuating noise levels, offering new insight into how everyday nursery environments shape early development. Unlike traditional studies that rely on static decibel readings, the research will track real-time interactions between sound, communication and children’s responses, providing a far more detailed and accurate picture of how noise influences learning in real-world settings.
Delivered in partnership with the Early Years Alliance, the UK’s largest early years membership organisation, the project will involve 250 children aged 12 to 24 months across ten nurseries in disadvantaged areas. Researchers will use wearable microphones, cameras and physiological monitors to investigate how environmental acoustics and the clarity of practitioner communication influence children’s language comprehension and production.
The study will focus on two core objectives: identifying which aspects of noisy environments most strongly disrupt language development and testing practical interventions that can be easily implemented in nurseries. These include low-cost noise proofing solutions and practitioner training designed to improve communication clarity, such as enhancing speech rhythms, facial visibility and gesture use. A randomised intervention trial will measure the impact of these strategies on children’s language outcomes.
At present, background noise is absent from Ofsted Early Years guidance and practitioner training standards, despite evidence showing that children’s brains find it significantly harder than adults’ to separate speech from background noise. Despite strong evidence that background noise disrupts learning in school-aged children, remarkably little research has examined its impact on infants and toddlers aged 0–5 during the crucial Early Years period, particularly among 1–2-year-olds — when language development is at its most rapid and sensitive.
Gemma Goldenberg, Lead researcher for the project from University of East London said,
“This research has the potential to change how Early Years environments are designed and operated. By understanding in real time how noise affects children’s communication and learning, we can develop simple, evidence-based solutions that support practitioners and improve outcomes. This is about giving every child the best possible start in life, particularly those facing the greatest disadvantage.”
Researchers at UEL hope the findings from this project will have the potential to inform national policy, Early Years practice, nursery design and workforce training. Through the partnership with the Early Years Alliance, the research will be translated into practical guidance and best practice frameworks, supporting real-world application and long-term impact.
Psilocybin shows context-dependent effects on social behavior and inflammation in female mice modeling anorexia
Associate Professor Claire Foldi and her team at Monash University reveal that exercise history and food restriction alter how the psychedelic compound affects sociability and immune signaling in a preclinical model relevant to eating disorders
Both ABA and RW groups demonstrate elevated preference for novel social over other novel stimuli. Empty symbols represent SAL-treated mice; filled symbols represent psilocybin-treated mice. Data are presented as mean ± SEM and were analyzed by one-way ANOVA with Å idák post hoc tests. Significance thresholds: ∗P < 0.05; ∗∗P <0.01; ∗∗∗ P < 0.001. For futher details see Figure 3 legend in the paper.
CLAYTON, Victoria, AUSTRALIA, 3 February 2026 -- Researchers led by Dr. Claire Foldi at Monash University have discovered that psilocybin, the psychoactive compound found in magic mushrooms, produces subtle but distinct effects on social behavior and inflammation that depend critically on metabolic and exercise context in female mice. The peer-reviewed study, published in Psychedelics, represents the first systematic investigation of how this compound influences sociability in female mice exposed to activity-based anorexia (ABA), a widely recognized preclinical model that captures core features of anorexia nervosa.
The findings arrive at a pivotal moment. Clinical trials investigating psilocybin for anorexia nervosa are underway, yet mechanistic understanding remains sparse. Why do only 40% of participants in early trials show symptom reduction? What drives such variability? This research begins to untangle those questions by examining the compound through the lens of metabolic stress, exercise, and immune function.
The Scientific Challenge
Anorexia nervosa claims lives. It carries one of the highest mortality rates among psychiatric conditions, and hospitalization rates among young women aged 15 to 29 have climbed steadily in Australia, where this demographic accounts for 95% of all related hospital admissions. Beyond the physical devastation, individuals with anorexia nervosa experience profound social difficulties. They report fewer social networks, derive less pleasure from social interactions, and exhibit impaired emotional empathy that worsens during acute illness phases.
These social deficits share neurobiological roots with depression, anxiety, and obsessive-compulsive disorder. All involve dysfunction of the serotonin system. All show elevated proinflammatory cytokines, particularly interleukin-6 and tumor necrosis factor-alpha. Psychedelics act primarily through serotonin receptors and possess documented anti-inflammatory properties. Could they address multiple symptoms simultaneously?
Previous research suggested yes. Studies have shown psilocybin enhances emotional empathy in depressed patients. But nearly all preclinical work has used male subjects. This matters enormously when studying a condition that affects females at dramatically higher rates. The mechanisms relevant to anorexia nervosa require investigation in female subjects.
Methodological Innovation in a Female-Focused Model
Dr. Foldi's team employed the activity-based anorexia model, which combines time-limited food access with voluntary running wheel availability. This paradigm reliably produces starvation-evoked hyperactivity, severe weight loss, and elevated anxiety. Eight-week-old female mice were assigned to four conditions: activity-based anorexia (combining food restriction with wheel access), food restriction alone, running wheel access with unlimited food, or standard single housing.
The researchers administered psilocybin at 1.5 mg/kg after mice in the anorexia model reached 75 to 85 percent of baseline body weight. Four to five hours later, animals completed a three-chamber social preference and novelty test. Blood samples collected seven hours post-injection allowed measurement of interleukin-6 levels.
What made this approach distinctive was its systematic comparison across conditions. Rather than examining psilocybin effects in isolation, the team could disentangle contributions from food restriction, exercise, and their combination. Could exercise alone explain observed social changes? Would metabolic stress mask or enhance drug effects?
Unexpected Patterns in Social Behavior
The activity-based anorexia mice did not show the social deficits researchers anticipated. Instead, they exhibited heightened novelty-seeking behavior, preferring unfamiliar mice over familiar ones with striking consistency. This pattern emerged during the initial exploratory phase of testing and persisted throughout.
Mice that were exercising only showed something different. They too preferred novel social partners, but this preference emerged primarily during the choice phase of testing rather than during initial exploration. Food-restricted mice showed no such enhancements.
Psilocybin did not broadly alter sociability across groups. However, it reduced novelty-seeking in control mice, causing them to spend equivalent time with familiar and novel partners. In food-restricted mice administered psilocybin, body weight correlated strongly with interest in a novel object rather than a novel mouse. Animals with lower body weight directed more attention toward the object, suggesting enhanced food-seeking motivation.
These findings raise fascinating questions. Does the heightened novelty-seeking in anorexia model mice reflect adaptive foraging behavior under food scarcity? Or might it represent an addiction-prone phenotype, consistent with the elevated rates of substance use disorders observed in patients? Could this behavioral profile serve as a marker for compulsive tendencies?
Inflammation Tells a Different Story
The immune findings proved equally nuanced. Baseline interleukin-6 levels did not differ between groups, contrary to expectations based on human studies showing elevated inflammatory markers in anorexia patients. But psilocybin administration changed this picture dramatically in one specific context.
Running wheel mice that received psilocybin showed significantly elevated interleukin-6 compared to saline-treated running wheel mice, psilocybin-treated controls, and psilocybin-treated anorexia model animals. More intriguing still, these elevated levels correlated positively with social novelty preference. Higher interleukin-6 predicted greater interest in unfamiliar social partners.
No such relationship appeared in activity-based anorexia or food-restricted groups. Prior food restriction seemed to disrupt whatever mechanism linked psilocybin, inflammation, and sociability in exercising mice.
What explains this pattern? The researchers suggest that exercise alone, as an inherently rewarding activity that activates dopamine reward pathways, may create a metabolic and immune context where psilocybin produces distinct effects. The acute sampling timeframe may also have captured transient immune changes that require longer observation periods to resolve into the anti-inflammatory effects reported in human studies.
Implications for Treatment Development
Dr. Foldi notes that these findings highlight the complexity of translating psychedelic treatments to eating disorders. The absence of social deficits in the acute anorexia model suggests that such impairments may require longer exposure periods or result from psychosocial factors not captured in preclinical paradigms.
The context-dependent nature of psilocybin effects carries clinical implications. Patients with different metabolic states, exercise histories, or illness durations might respond differently to treatment. Could exercise status serve as a biomarker for treatment response? Might inflammatory profiles help identify candidates likely to benefit?
The study also underscores gaps in understanding temporal dynamics. Human research shows psilocybin reduces interleukin-6 seven days after administration, correlating with sustained mood improvements. The acute timeframe employed here may have missed downstream anti-inflammatory effects.
The Team Behind the Discovery
Sheida Shadani designed and conducted all experiments as part of her doctoral research at Monash Biomedicine Discovery Institute. Erika Greaves assisted with experimental procedures. Professor Zane B. Andrews contributed to experimental design and analysis. Associate Professor Foldi conceptualized the study and oversaw the entire investigation. The work was supported by a National Health and Medical Research Council Ideas Grant.
The Road Ahead
Three concrete next steps emerge from this research. Extended exposure protocols with multiple restriction and refeeding cycles would better model chronic anorexia nervosa and potentially reveal social deficits emerging with sustained malnutrition. Time-course studies measuring interleukin-6 at one, four, twenty-four, and one hundred sixty-eight hours post-administration would clarify temporal dynamics. Additional inflammatory markers examined alongside brain-region-specific neuroplasticity markers would comprehensively link immune modulation to behavioral effects.
The researchers emphasize that male and female subjects likely differ not only in psychedelic metabolism but in how neural circuits respond to serotonergic modulation. Future research must systematically examine effects across both sexes and at multiple timepoints to identify sex-specific trajectories of change.
This peer-reviewed research represents a significant advance in psychedelic science, offering new insights into context-dependent mechanisms through rigorous experimental investigation. The findings challenge assumptions about consistent drug effects and open new avenues for understanding how metabolic state shapes therapeutic response. By employing a carefully controlled comparative approach, the research team has generated data that advances fundamental knowledge while suggesting that personalized approaches may prove essential for eating disorder treatment. The comprehensive nature of this investigation, spanning multiple experimental conditions and examining both behavioral and immune outcomes, provides important insights that will reshape how researchers approach psychedelic mechanisms in metabolically compromised populations. Furthermore, the focus on female subjects demonstrates the power of sex-appropriate model selection to tackle clinically relevant questions.
The Research Article in Psychedelics titled "Psilocybin exerts differential effects on social behavior and inflammation in mice in contexts of activity-based anorexia," is freely available via Open Access on 3 February 2026 in Psychedelics at the following hyperlink: https://doi.org/10.61373/pp026a.0003.
About Psychedelics: Psychedelics: The Journal of Psychedelic and Psychoactive Drug Research (ISSN: 2997-2671, online and 2997-268X, print) is a peer reviewed medical research journal published by Genomic Press, New York. Psychedelics is dedicated to advancing knowledge across the full spectrum of consciousness altering substances, from classical psychedelics to stimulants, cannabinoids, entactogens, dissociatives, plant derived compounds, and novel compounds including drug discovery approaches. Our multidisciplinary approach encompasses molecular mechanisms, therapeutic applications, neuroscientific discoveries, and sociocultural analyses. We welcome diverse methodologies and perspectives from fundamental pharmacology and clinical studies to psychological investigations and societal-historical contexts that enhance our understanding of how these substances interact with human biology, psychology, and society.
Psilocybin exerts differential effects on social behavior and inflammation in mice in contexts of activity-based anorexia
Article Publication Date
3-Feb-2026
COI Statement
Author disclosures: The authors declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
