No solo es dormir una hora menos: qué provoca el cambio horario en la atención, el humor y el bienestar psicológico

Source: The Conversation – (in Spanish) – By Oliver Serrano León, Director y profesor del Máster de Psicología General Sanitaria, Universidad Europea

Este domingo 29 de marzo vuelve una escena conocida: el calendario oficial publicado en el BOE marca el inicio del horario de verano en España. En términos prácticos, el reloj se adelanta una hora de manera simultánea en todo el territorio, aunque con distinta hora oficial en la península y en Canarias, tal como recoge el Real Decreto que regula el cambio horario. Sobre el papel parece un ajuste menor. Pero para el cerebro no siempre lo es.

No se trata solo de una mala noche

Desde la psicología, lo relevante no es tanto la hora “perdida” como el desajuste que se produce entre el tiempo social y el tiempo biológico. Nuestro organismo funciona con ritmos circadianos, es decir, oscilaciones internas que regulan el sueño, la activación, la temperatura corporal, el apetito y buena parte de la regulación emocional. Cuando el horario oficial se adelanta de golpe, el cuerpo no siempre acompasa ese cambio al mismo ritmo. Por eso, muchas personas experimentan durante unos días una sensación parecida a un pequeño jet lag social”: cuesta más dormirse, levantarse y rendir como si nada hubiera pasado.

Uno de los errores más frecuentes es pensar que el cambio se reduce a dormir una hora menos la madrugada del domingo. La evidencia apunta a algo más complejo. Una revisión reciente de 27 estudios concluye que la transición se asocia con efectos adversos sobre la duración y la calidad del sueño, además de más somnolencia diurna.

El impacto, además, parece ser más claro en las personas de cronotipo vespertino, es decir, aquellas que tienden a acostarse y activarse más tarde. No es solo una noche peor: en algunos casos hay varios días de adaptación incompleta.

Ese pequeño déficit de sueño tiene consecuencias psicológicas reconocibles. A menudo no aparece como un gran problema clínico, sino como una suma de “microdeterioros” cotidianos: más despistes, peor concentración, más lentitud mental, menor tolerancia a la frustración e irritabilidad.

La literatura científica sobre sueño, ritmos circadianos y salud mental muestra que las alteraciones del descanso y de la sincronía circadiana no solo afectan a cómo dormimos, sino también a la atención, la cognición y el estado de ánimo. En otras palabras: cuando el reloj biológico va desacompasado, también lo hacen parte de nuestros recursos psicológicos.

Atención, errores y fatiga: los efectos más inmediatos

El cambio de primavera también se ha relacionado con un aumento de la fatiga y con peor rendimiento en tareas que exigen vigilancia sostenida. No es casualidad que algunas investigaciones hayan observado efectos en contextos donde un pequeño descenso de alerta importa mucho.

Un estudio publicado en Current Biology encontró que el adelanto horario se asociaba con un incremento del 6 % en el riesgo de accidentes de tráfico mortales en Estados Unidos. El dato no significa que todas las personas vayan a conducir peor de forma llamativa, pero sí refuerza una idea básica: incluso una alteración aparentemente modesta del sueño puede tener efectos reales sobre la atención y el tiempo de reacción.

No afecta a todos por igual

Y como ocurre con casi todos los fenómenos psicológicos, no impacta del mismo modo en toda la población. Quienes suelen acostarse tarde, quienes ya arrastran deuda de sueño o quienes tienen horarios matutinos rígidos suelen notar más el desfase.

También los adolescentes constituyen un grupo especialmente sensible. Un estudio sobre sueño en esas edades tras el cambio de primavera observó que el ajuste puede dificultar el descanso y asociarse con un descenso del funcionamiento cognitivo. No resulta extraño: la adolescencia ya viene acompañada de una tendencia biológica a retrasar la hora de dormir, y el adelanto del reloj va justo en sentido contrario.

¿Puede afectar también al estado de ánimo?

Sí, pero aquí conviene ser prudentes. Sería exagerado afirmar que el adelanto de una hora “provoca” por sí solo trastornos psicológicos. La evidencia es más matizada. Por ejemplo, una conocida investigación realizada en Dinamarca encontró un aumento del 11 % en los episodios depresivos unipolares tras el cambio de otoño, no después del de primavera. Más recientemente, una investigación poblacional en Inglaterra encontró poca evidencia de un efecto agudo del cambio al horario de verano sobre los eventos de salud mental registrados en atención sanitaria.




Leer más:
Madrugar no le hará más rico y puede perjudicar su salud


La lectura razonable, por tanto, no es alarmista: para la mayoría de las personas el cambio de hora no generará un problema clínico, pero sí puede empeorar temporalmente el humor, la energía y la regulación emocional, sobre todo si ya existía vulnerabilidad previa.

Esta cautela encaja bien con lo que se sabe sobre la relación entre ritmos biológicos y salud mental. Estudios recientes indican que, en personas con trastornos del estado de ánimo, las alteraciones de la fase circadiana pueden preceder a los síntomas del estado de ánimo. Eso no implica que el adelanto horario sea una causa única, pero sí ayuda a entender por qué un reajuste aparentemente trivial puede notarse más en algunas personas que en otras.

Cómo amortiguar el impacto

La mejor forma de afrontar el cambio no es dramatizarlo, pero tampoco ignorarlo. La investigación sobre adaptación circadiana recuerda que la luz matutina es una de las señales más potentes para adelantar el reloj biológico y que la luz vespertina tiende a retrasarlo.

Por eso ayuda exponerse a la luz natural por la mañana, evitar una sobreestimulación lumínica intensa por la noche y proteger especialmente el descanso los días previos y posteriores. También puede ser útil adelantar progresivamente 15 o 20 minutos la hora de acostarse en las jornadas anteriores, en lugar de esperar a que el cuerpo resuelva solo el desfase de un día para otro.

En definitiva, el cambio de hora funciona como un recordatorio incómodo pero útil: la mente no opera al margen del sueño, de la luz ni de los ritmos biológicos. Una sola hora puede parecer poco, pero cuando esos 60 minutos se traducen en peor descanso, más fatiga, menos atención y más irritabilidad, deja de ser solo un ajuste del reloj y se convierte también en una cuestión de bienestar psicológico.

The Conversation

Oliver Serrano León no recibe salario, ni ejerce labores de consultoría, ni posee acciones, ni recibe financiación de ninguna compañía u organización que pueda obtener beneficio de este artículo, y ha declarado carecer de vínculos relevantes más allá del cargo académico citado.

ref. No solo es dormir una hora menos: qué provoca el cambio horario en la atención, el humor y el bienestar psicológico – https://theconversation.com/no-solo-es-dormir-una-hora-menos-que-provoca-el-cambio-horario-en-la-atencion-el-humor-y-el-bienestar-psicologico-279465

Brain drain in rural Wales isn’t inevitable ‑ we asked gen Z what would make them stay

Source: The Conversation – UK – By Sonya Hanna, Lecturer in Marketing, Bangor University

What we feel about our hometowns – the places we grew up, the people we know, the memories we made – shapes who we are.

For many young people in rural Wales, those ties run deep. The mountains, villages and slate landscapes are more than scenery. They are part of family stories and everyday life. But even though they care deeply about where they live, many feel they are being pushed to leave for education or work.

Our report focused on the slate landscape of north-west Wales, a Unesco world heritage site known for its historic mines and quarries. The area includes towns like Blaenau Ffestiniog, where the slate industry once shaped both the economy and the culture.

We found that generation Z – people now in their teens and twenties – often want to stay. But they feel overlooked in conversations about the future of their communities. They see the effects of what is often called “brain drain”, which is when younger people leave rural areas for cities because jobs, education and opportunities are limited.

Over time, this can hollow out local economies and communities. But many of the young people we spoke to believe things could be different.

A growing pressure to leave

Rural areas around the world face similar challenges. Tourism may bring visitors and income, but it can also drive up house prices and lead to second homes that stand empty for much of the year. Transport links can be poor, while secure, well-paid work can be scarce. And north Wales is no exception.

A 2025 report commissioned by a Welsh government organisation on migration and the low-carbon economy in the area found the regional workforce had shrunk by about 4,000 people between 2021 and 2022. Only 22% of survey respondents felt there were good employment opportunities locally. Just 26% believed public services in their area met their needs.

Among young people, the outlook can feel even more uncertain. One 2022 study found that 81% of young people in rural Wales believed they would have to move away within the next five years for education, training or work.

Governments are aware of the problem. Welsh government strategies emphasise the need for sustainable tourism and for young people to play a bigger role in shaping it.

International tourism guidelines also stress the importance of balancing economic development with environmental protection and cultural heritage. But in practice, young people often feel absent from the conversations among governments and the tourism industry.

Plans for the visitor economy in the county of Gwynedd and the wider Eryri National Park (sometimes known as Snowdonia) acknowledge the lack of career opportunities and the reliance on seasonal work. Yet young people themselves are rarely treated as a distinct group to consult directly. This is important because they are the generation that will decide whether these communities thrive or slowly empty.

An abandoned slate quarry.
The abandoned Cwmorthin Slate Quarry at Blaenau Ffestiniog.
Rob Thorley/Shutterstock

‘It’s the foundation of everything’

The young people we spoke with are deeply connected to the slate landscape. As one participant told us: “It’s like the foundation of everything that my life has been built on in a way, because my house is built on slate, it’s like on my roof… About four or five of us grew up together at the same age, and we would just spend hours on the slates drawing with chalk on the slates.”

These emotional ties matter. They help explain why many young people want to stay, even when opportunities elsewhere may look more attractive. But attachment alone is not enough. Young people want to shape the future.

One message came through repeatedly in our research: that young people want to be involved. They do not want their participation to be symbolic or tokenistic. They want a genuine role in shaping tourism, local development and the future of their communities.

Many had practical ideas. Some suggested developing guided heritage walks that combine history with outdoor activities such as climbing or trail running. Others proposed sensory walking routes with audio guides explaining the area’s culture and landscape. Several talked about using social media to promote the area and tell local stories in new ways.




Read more:
Wales plans a tourism tax from 2027 – what it means for visitors and communities


They also spoke about the slate caverns themselves, the vast underground spaces once used for mining. These could host festivals, cultural events or youth activities linked to the area’s Unesco status. Such ideas are not unrealistic. Adventure tourism companies already operate in parts of the slate landscape, using former quarry sites for activities such as zip lining. Young people want to help shape what comes next.

Addressing rural brain drain is not just about persuading young people to stay. It’s about creating communities in which they can imagine a future. In some places, this has been achieved by building cultural hubs that give young people access to training, creative opportunities and pathways into employment.

Without such efforts, rural areas can become increasingly polarised with large numbers of teenagers in school, followed by a population dominated by older, often retired residents. The result is a hollow middle generation.

But our research suggests another path is possible. Young people in north-west Wales care deeply about their home landscapes. They understand their cultural and environmental value. They have ideas about how tourism and heritage could evolve in sustainable ways. What they want most is simple. Not to leave but to be heard.

The Conversation

The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

ref. Brain drain in rural Wales isn’t inevitable ‑ we asked gen Z what would make them stay – https://theconversation.com/brain-drain-in-rural-wales-isnt-inevitable-we-asked-gen-z-what-would-make-them-stay-268053

Is it safe to eat cold leftovers?

Source: The Conversation – UK – By Primrose Freestone, Senior Lecturer in Clinical Microbiology, University of Leicester

Cold pizza, a favourite for many, could be risky if it hasn’t been stored properly. Monkey Business Images/ Shutterstock

There are few things better than a cold slice of pizza for breakfast. But as delicious as scarfing down cold pizza is, there’s also a risk of food poisoning if you aren’t careful.

Food poisoning is caused by eating food that has become contaminated with pathogenic bacteria, fungi or viruses. Although most people know that food poisoning can be caused by poorly cooked foods or risky food preparation habits, improperly stored leftovers are also a key cause. It’s therefore extremely important you take care when storing leftovers to avoid harming your health.

Here’s my advice as a microbiologist for staying safe when eating your favourite cold leftovers.

Leftover pizza

You can get food poisoning from cooked pizza in a number of ways. Whether that’s because some of the ingredients are raw, undercooked or spoiled, or if the pizza has touched a surface with germs on it (including being handled by someone who hasn’t washed their hands).

Surprisingly, the dried herbs and spices that people often sprinkle on their pizzas (such as basil, pepper and oregano) can also be susceptible to microbial contamination. This contamination can occur during the harvesting and production phases, or due to improper storage by consumers. Some of the foodborne pathogens that can potentially survive on dried herbs include bacteria that can cause food poisoning, including Salmonella, Bacillus cereus and Clostridium perfringens.

Even if these dried herbs have been sterilised by the heat of a freshly baked pizza, if left at room temperature for too long after cooking these or any of the other pizza toppings, can provide the perfect snack for potentially harmful germs.

So if you’re a cold pizza lover, the best way to reduce your risk of food poisoning is to ensure any leftovers are refrigerated within two hours of being delivered or cooked. This should mean the pizza is safe to have cold for breakfast.

Once in the fridge, the leftover pizza needs to be stored covered (to avoid contamination from airborne germs) and eaten within two days. Note that putting leftover food in the fridge only slows bacterial growth, which is why leftovers should be eaten within two days maximum.

If the pizza is left at room temperature for more than a few hours, germs will grow quickly. This can make the pizza unsafe to eat the next day – no matter how tasty it might still look or smell.

Leftover chicken

Cooked chicken is highly perishable once cooled. Its high water and nutrient content and low acidity favours the growth of food poisoning bacteria, especially if it isn’t stored correctly after cooking.

It’s also important you only save chicken for leftovers if it has been cooked properly. If there’s any trace of blood in the cooked chicken’s juices, do not eat it – and certainly don’t save it for later.

This is because raw chicken may be contaminated with the food poisoning germs Campylobacter, Salmonella or Clostridium perfringens, so thoroughly cooking your chicken is essential.

If even a tiny amount of the chicken under-cooked, food poisoning germs still present within the tissues can start growing even when the meat is stored in the fridge. These germs may not be detectable by smell or sight.

A person places a plastic tupperware container full of leftovers in the fridge next to three other containers of leftovers.
Leftovers should be covered and placed in the fridge within a couple of hours of cooking.
TatianaKim/ Shutterstock

To stay safe, once you’ve removed your cooked chicken from the oven or rotisserie packaging, any that you aren’t planning to immediately eat should be covered and refrigerated as soon as possible after cooling. Ideally, it should spend no more than two hours at room temperature.

Cooked chicken can be stored for up to three days in the fridge. But again, if you notice blood in any part of the chicken, you absolutely should not eat it – whether cold or reheated – as this indicates it has been under-cooked and may be contaminated with germs.

Leftover rice dishes

Leftover rice dishes of any kind – whether that’s fried rice, burritos or risotto – have a major food poisoning risk. This is because uncooked rice can contain spores of Bacillus cereus, a common food poisoning bacteria that prefers starchy foods.

Although Bacillus cells are killed by the heat of cooking, their spores are heat resistant and can survive. If a cooked rice dish is then left at room temperature for more than two hours, the Bacillus spores have time to develop into bacteria and multiply. These spores are also able to release toxins into the cooked rice, which can potentially cause severe vomiting and diarrhoea lasting up to 24 hours.

If cooked rice needs to be saved, it should be covered once cooked, cooled quickly, then refrigerated for no more than 24 hours.

Cooked rice can be eaten cold, but only if has been cooled quickly after cooking and stored as quickly as possible in the fridge. It’s also best to consume cold cooked rice within 24 hours as B cereus spores can germinate during longer storage periods.

Left over canned foods

To safely store canned leftovers, it’s essential they’re covered and refrigerated to avoid contamination from airborne germs.

It’s considered safe to store the food in the original can as this has been sterilised in processing. But for flavour reasons, you might want to transfer it to a covered plastic or glass container.

Highly acidic foods, such as canned tomatoes, can be stored refrigerated for five to seven days. Low acidity canned foods, such as meat, fish, fruit, vegetables and pasta, can only be stored for up to three days. Acidic foods last longer because the acid inhibits the growth of food poisoning bacteria.

Leftovers can be safe to eat cold. Just make sure you refrigerate them as quickly as possible after cooking and consume within a day or two.

The Conversation

Primrose Freestone does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. Is it safe to eat cold leftovers? – https://theconversation.com/is-it-safe-to-eat-cold-leftovers-278012

UK government recommends maximum one hour of screen time for younger children: what the evidence says

Source: The Conversation – UK – By Olga Fotakopoulou, Associate Professor in Developmental Psychology, Birmingham City University

ADDICTIVE STOCK/Shutterstock

New UK government guidance recommends that screen time for children under two should be avoided, except for shared activities such as video calls. For children aged two to five, a maximum of an hour a day is suggested. The guidance also outlines that watching screens together is better than children viewing alone.

This echoes guidance from the World Health Organization recommending no screen time for infants under two, and no more than one hour per day for older children aged four and under.

The early years, especially from birth to age six, are a critical period for developing social and communication skills. This is when children are learning how to connect with others, communicate their needs and understand the signals people give them. Given the increasing presence of touchscreen technologies in young children’s environments, understanding how these tools influence early developmental trajectories is essential.

Touchscreen technology offers new opportunities for learning and play. But there are also questions about its impact on children’s social development, communication and school readiness. Researchers and health organisations have been working to consider how digital media interacts with children’s development and shapes their early experiences.

Excessive touchscreen use has been associated with delays in expressive language, reduced attention spans, and poorer interactions between parents and children.

Yet the picture is not one-sided. My research with colleagues highlights that early exposure to multi-modal technologies – tools that combine sound, images, touch and movement – can shape children’s social development in both positive and negative ways.

Language skills and collaboration

On the positive side, interactive and engaging uses of technology can foster language development. Studies show that digital platforms encouraging storytelling, role play and collaborative activities can enhance children’s competence in communication.

Touchscreens can also help children to work together on shared tasks. Multi-touch interfaces promote joint problem-solving, turn-taking and dialogue. This can strengthen cooperation and peer relationships.

In classrooms, tablets often become focal points for group activities. Children share knowledge, assist one another and collaborate on projects, which can enhance social interaction skills and confidence.

Touchscreens also create opportunities for social play and communication across distance. Video-communication apps such as Skype and FaceTime allow children to maintain relationships with family and friends, supporting emotional bonds and social connection.

Three children using a tablet together
Children can collaborate using screens.
Mkosi Omkhulu/Shutterstock

Creative expression is another area where digital tools can shine. Drawing, animation, and storytelling apps encourage children to share ideas and collaborate. This can promote cooperation and social bonding.

Passive use

However, these benefits coexist with significant challenges. Excessive screen time can reduce opportunities for face-to-face interaction, limiting children’s practice of conversational skills and emotional understanding. When children use screens passively or in isolation, they may become less engaged in socialising with others.

Parents’s use of screens is another concern. When parents are absorbed in their own devices, they talk less with their children. This reduces opportunities for educationally meaningful conversations.

Touchscreen use can also affect communication more directly. Studies show that electronic books may shift parents’ attention toward the device rather than the story, displacing meaningful conversation and reducing the quality of shared reading experiences. Some research suggests that heavy touchscreen use may make it harder for children to pick up social and emotional cues. This may affect their ability to decode social situations.

Importantly, the impact of touchscreen use is shaped by several mediating factors. Children learn more effectively when adults or their classmates model how to use touchscreen devices. As the government guidance states, it’s also better if adults watch screens together with their child, rather than their child watching alone.

Parents’ views and wider culture matter too. In research I carried out with colleagues, we found that cultural perceptions about what makes a good childhood shaped parents’ choices. In Portugal and Norway, strong cultural emphasis on outdoor play, social interaction, and connection with nature led parents to prioritise these activities over touchscreen use.

These cultural expectations influence how parents interpret and regulate young children’s digital practices, showing that attitudes toward technology are closely tied to wider national discourses about childhood. Educational settings further influence this. The way technology is integrated into classrooms can reinforce social behaviour.

These findings have important implications for school readiness. Social communication skills, such as turn-taking, listening, expressing ideas, and understanding others, are foundational for success in early education. Touchscreens can support these skills when used interactively and collaboratively. But when screen use replaces conversation, imaginative play or peer interaction, it may hinder the development of the very abilities children need for school and their social lives.

The evidence suggests that the question is not whether children should use touchscreens, but how. High-quality, interactive, and socially supported digital experiences can enrich development. Passive or excessive use can undermine it.

However, it’s vital to recognise that not all digital content is created equal. The quality and context of technology use can have a significant impact. As digital technologies continue to evolve, ensuring that young children’s screen experiences are balanced, meaningful, and socially engaging will be essential.

The Conversation

I have received funding from EU and Nuffield Foundation (but not for this project).

ref. UK government recommends maximum one hour of screen time for younger children: what the evidence says – https://theconversation.com/uk-government-recommends-maximum-one-hour-of-screen-time-for-younger-children-what-the-evidence-says-275752

HRT patches to treat prostate cancer – here’s how it works

Source: The Conversation – UK – By Justin Stebbing, Professor of Biomedical Sciences, Anglia Ruskin University

Andrey Popov/Shutterstock

Women’s HRT patches can treat prostate cancer just as effectively as standard hormone injections – but with fewer of the worst side-effects – according to a large UK trial published in the New England Journal of Medicine. The finding could change how men with prostate cancer that has spread beyond the gland are treated for years to come.

Standard treatment has long relied on shutting down testosterone, the fuel that drives many tumours, through regular injections that turn off the body’s own hormone production. They are effective, but they are blunt tools, dragging down oestrogen as well as testosterone and taking a heavy toll on quality of life with hot flushes, brittle bones and metabolic problems. Now, in an elegant twist of biology, the very hormone patches used to ease menopause symptoms in women are being repurposed to treat prostate cancer in men.

The idea sounds counterintuitive at first. Why would giving oestrogen to men help control a cancer fed by testosterone? The answer lies in feedback loops.

Oestradiol, the form of oestrogen in standard HRT patches, signals to the brain that there is plenty of sex hormone around. The brain then dials down its instructions to the testes to make testosterone, so levels of the male hormone fall just as effectively as with injections designed to switch production off directly. In other words, you can arrive at the same hormonal destination by a more subtle route.

In the new trial, more than 1,300 men, with an average age of about 72, were randomly allocated to either the standard hormone injections or to skin patches delivering oestradiol, identical to those used for menopausal symptoms. Many also received radiotherapy and sometimes chemotherapy, reflecting how these cancers are treated in routine practice.

After three years, the proportion of men alive without the cancer progressing was almost identical in the two groups: 87% in the patch arm and 86% with injections. Essentially, a dead heat for effectiveness.

Where the approaches really diverged was in how men felt. Because injections strip away oestrogen as well as testosterone, they create a kind of sudden “male menopause”, complete with hot flushes, night sweats and thinning bones.

In the trial, almost nine in ten men on injections reported hot flushes. Among those wearing patches, less than half did.

A box of HRT patches.
Hormone patches were as effective as injections, but with far fewer side-effects.
Nicola_K_photos/Shutterstock.com

Bone health also favoured the patches, with fractures roughly twice as common in the injection group. Men on patches, however, paid a different price: more than 80% developed breast tissue swelling, compared with about 40% of those on injections. This gynaecomastia, as it’s called, is rarely dangerous, but it can be very uncomfortable and for some men deeply unwelcome.

Those trade-offs go to the heart of modern cancer care. It is no longer enough just to count years of survival. As more people live for longer with their disease controlled, the quality of those years matters just as much. Prostate cancer is already the most common cancer in UK men, with around 64,000 new cases and 12,000 deaths each year.

Many of those men will spend years on hormone therapy. If two treatments tame the tumour equally well, the one that lets you sleep through the night without wrestling with hot flushes, preserves your bones and can be applied at home rather than in a clinic starts to look very attractive.

The practical advantages of patches are easy to appreciate. Injections require repeated trips to hospital or GP surgeries and can be painful. Patches are simply stuck on the skin and replaced at home, with oestradiol absorbed steadily into the bloodstream.

This “transdermal” delivery – through the skin rather than the stomach – avoids the liver processing the hormone and appears to blunt some of the heart and clotting risks historically linked to oestrogen tablets taken by mouth. That is important because earlier attempts decades ago to treat prostate cancer with oestrogen pills fell out of favour when they were linked to more heart attacks and strokes. The current research essentially resurrects that old idea with a safer formulation and route.

The trial is part of a broader shift towards re-examining assumptions in oncology. For years, the focus in prostate cancer has been on newer, more targeted drugs and immunotherapies. Yet here we have a relatively cheap, widely available hormone patch being asked to do double duty: easing menopausal symptoms in one half of the population and quietly disabling a common male cancer in the other.

It is a reminder that innovation is not always about glamorous new molecules. Sometimes it is about taking an existing tool and using human physiology more cleverly.

None of this means that injections will vanish. For some men, breast swelling from patches may be intolerable despite the benefits. For others, the familiarity and simplicity of a regular injection still appeals. There will also be questions about which patients are best suited to this approach, how it interacts with newer generations of hormonal drugs and whether long-term effects on the heart remain reassuring.

Regulatory approval is still needed

Regulators will need to approve oestradiol patches specifically for prostate cancer, not just menopause, before health systems such as the NHS can routinely offer them in this way. Cost-effectiveness analyses and real-world data will follow.

What the study does immediately is widen the menu of choices. Instead of a single standard hormone therapy pathway, men with prostate cancer may soon be able to sit down with their doctors and weigh the trade-offs in a more personal way: fewer hot flushes and better bones with a high chance of breast swelling, or more traditional injections with their own set of problems. That conversation may feel more like choosing between HRT options in the menopause clinic than the old, paternalistic model of cancer care where one default protocol is imposed.

It is also a striking example of how women’s health and men’s health intersect. For years, debates around HRT have focused on its risks and benefits for women navigating menopause, with strong views on both sides. Now, the same patches are being recast as a potential life-prolonging treatment for men.

It is hard not to see a poetic symmetry there: a therapy designed to buffer women from the hormonal upheavals of midlife, helping men withstand the hormonal upheaval we deliberately induce to control prostate cancer. As more evidence accumulates, the humdrum little square of adhesive on the skin may come to symbolise a new, gentler chapter in how we use hormones against one of our most common cancers.

The Conversation

Justin Stebbing does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. HRT patches to treat prostate cancer – here’s how it works – https://theconversation.com/hrt-patches-to-treat-prostate-cancer-heres-how-it-works-279346

Young people more open to ditching meat than previously thought – new study

Source: The Conversation – UK – By Luke McGuire, Senior Lecturer, Department of Psychology, University of Exeter

vectorfusionart/Shutterstock

Eating meat and other animal products can have negative effects on our health, the environment and animal welfare.

Eating a more plant-based diet rich in wholefoods could prevent 27% of human deaths worldwide, according to the EAT–Lancet Commission on healthy, sustainable, and just food systems. It could also spare the lives of more than 80 billion animals a year and cause 75% less environmental damage.

While some European governments, such as Denmark, are introducing legislation that incentivises citizens to buy and eat plant-based food, progress is slow. That is partly due to the difficulty in changing adults’ minds about meat.

However, our new study shows that young people might be more open to ditching meat. We asked more than 1,000 young adults in the UK (with an average age of 23) whether they had thought about stopping eating meat when they were still at school. Half of our participants (48.5%) said they had thought about this. Surprisingly, 50.4% of those participants actually did stop eating meat for some period of time.

This finding opens a range of possibilities for encouraging and supporting people to eat more sustainably.

If the childhood and teenage years are a window when lots of people are already questioning what they eat, an important next step is to understand how schools, councils and peer groups can support those young people who are interested in trying to eat healthier, more ethical and sustainable diets.

In our study, we asked 1,063 young adults from the UK whether they had ever thought about stopping eating meat during childhood (up until the end of secondary school). Of the participants who said they had thought about stopping, half of this group (50.4%) did stop for days (15.3%), weeks (17.1%), months (20.7%), years (21.5%) or permanently (25.5%).

In a follow-up survey, we asked 461 young adults (all of whom said they had thought about stopping eating meat when they were younger) to tell us more about their experiences.

We wanted to know why people first thought about stopping eating meat. Participants had a range of reasons – some talked about feeling disgusted by meat, others had a “meat epiphany” where they realised where meat came from. We also wanted to know if there was anything that explained why some young people were able to stop. We found that parental support was key – it was more important than all the other psychological factors we looked at, including people’s attitudes towards animals and their disgust towards meat.

teens queuing at school canteen
Support from schools helps young people choose healthy, sustainable food choices.
Dragan Mujan/Shutterstock

We also found that most of the young people who had stopped eating meat during their school years returned to eating it (89.5%) at some later stage. This was for a range of reasons. Some stated that they had concerns for their health, others missed the taste of meat. Many talked about not wanting to cause an inconvenience to their family. They told us that their friends, schools and parents were all more supportive of them when they wanted to start eating meat again compared to when they had first stopped.

These findings suggest promising avenues for encouraging people to eat more sustainably. Our results suggest that a lot of people might already be thinking about reducing their meat intake when they’re young.

To do so, those who don’t have as much autonomy over their food choices need the support of their parents and schools. Many participants said that their new diet was an inconvenience for their family. This suggests that one place to offer support is in the family home. Understanding ways of teaching families to cook meals that can be easily adapted to meet their children’s dietary and nutritional requirements, without breaking the bank, could make a huge difference.

Cost is another important concern for families in this case. While research has shown that plant-based meat imitation products can be more expensive than their animal-based equivalents, on average shoppers spend less on a whole foods plant-based grocery shop than an animal-based trolley.

Healthy options

Some parents may worry that plant-based diets aren’t healthy for children and teenagers. However, research shows that carefully planned plant-based diets can support healthy living at every age and provide a diversity of dietary fibres important for gut health. In a recent review examining ten studies with more than 1,500 children, medical experts determined there is not enough evidence to say that vegan diets have negative effects on health, and that vegan children’s growth and nutrition was similar to that of omnivorous children.

However, dietary experts note that some key nutrients (such as iron, vitamin B12, vitamin D, calcium) essential for healthy development of tissues, metabolic and immune function and bone health, are naturally low in plant sources. As such plant-based diets and intake in young people should be monitored by health professionals. In spite of this, research has shown that shifting from a typical western diet to a more plant-based diet rich in wholefoods from the age of 20 could add a decade to life expectancy.

One limitation with our study is that we asked young adults to think back to their childhood. These kinds of retrospective methods aren’t perfect, as people sometimes mis-remember details from the past. An important next step will be to ask children and teenagers today what they think about this issue right now.

Despite this limitation, we think these findings offer a promising opportunity for anyone interested in supporting young people to advocate for themselves, the planet and other animals.

The Conversation

Luke McGuire receives funding from the ESRC.

Natalia Lawrence receives funding from the BBSRC (Diet and Health Open Innovation Research Club)

ref. Young people more open to ditching meat than previously thought – new study – https://theconversation.com/young-people-more-open-to-ditching-meat-than-previously-thought-new-study-277567

What’s behind Pakistan’s war with Afghanistan’s Taliban government?

Source: The Conversation – UK – By Michael Semple, Visiting Research Professor, The Senator George J. Mitchell Institute for Global Peace Security and Justice, Queen’s University Belfast

Pakistan has been at war with Afghanistan’s Taliban regime for just under one month. Yet the conflict, which was officially declared by Pakistan the day before the US and Israel launched their strikes on Iran, has been overshadowed by events in the Gulf.

Pakistan and the Taliban have made widely differing claims regarding the numbers of people killed on either side. The rising casualty toll only briefly captured global attention when a Pakistani airstrike hit a drug rehabilitation centre in Kabul on March 16, killing more than 100 people.

But the three weeks of fighting, with a brief pause for the Eid al-Fitr holiday between March 20 and 23, confirm for anyone who still doubted it, that the schism between Pakistan and the Taliban is real. Of course there are complex geopolitical and regional interests at play. India provides some support for the Taliban while China tries to balance its alliance with Pakistan and its more tentative relationship with the Taliban. But the conflict tells us more about the politics of the Taliban movement itself and its relationship with Pakistan.

The Taliban are happy to exploit the spectacle of the conflict with Pakistan as their latest bid for legitimacy. They pose to the Afghan population as defenders of national sovereignty. And they believe that their guerrilla tactics give them an advantage in ground fighting against what they disparagingly refer to as the “Punjabi army”. Meanwhile, their ideology, which is based on religious zeal tinged with nationalism, plays to historical Afghan ideas around resisting foreigners, including the defeat of the British Army of the Indus in the 1838-42 war, is a potent recruiting tool.

Pakistani militants

The Pakistani Taliban (TTP) are the key factor behind the breakdown in Afghanistan’s relations with Pakistan. The TTP are a group of Pakistani militants, inspired by the Afghan Taliban, but with their own leadership and structure. The Afghan Taliban have provided a haven in Afghanistan to the TTP that mirrors the refuge they themselves received in Pakistan until 2021.

In the run up to the latest war, the TTP escalated their insurgency against the Pakistan state. Now TTP leaders have declared themselves a part of the Taliban’s emirate. They claim to be fighting to impose the Taliban version of the emirate on the whole of Pakistan, not just the tribal areas of the frontier, where the TTP originated.

This may help Pakistan persuade other regional powers that the Taliban pose a threat to stability analogous to that posed by Iran – but with IEDs and suicide bombers instead of ballistic missiles and drones. The problem for the Pakistan army is that neither previous efforts at containment of the Taliban nor the current limited aerial campaign against them has made the extremist regime amenable to cooperation.

Building grievance

For years, the Taliban were widely denigrated as a proxy force that had been created and supported by Pakistan and served Islamabad’s interests. This is simply wrong. The Taliban as a movement is rooted in Afghan culture and history, dominated by conservative Sunni clerics and madrassah (Islamic school) students from the Kandahari branches of Afghanistan’s Pashtun tribes. It was these tribes’ 18th-century rebellions against their Persian overlords which led to the emergence of modern Afghanistan. For three decades the movement has pursued a vision of imposing the Taliban’s Islamic system on Afghanistan.

They only accepted safe haven in Pakistan because they saw it as their best chance of outlasting the US intervention in Afghanistan.

The Taliban never felt much gratitude towards their hosts. Instead they accumulated grievances against their benefactors during the safe haven period. These grievances started soon after 9/11, when Pakistan helped the US detain numerous Taliban leaders. By August 2021 the Taliban had a pantheon of senior figures whose deaths they blamed on Pakistan – such as their former defence minister Obaidullah Akhund in 2010 and their second leader Mullah Akhtar Mohammad Mansoor in 2016.

When the Taliban leaders and security chiefs returned to government in Afghanistan in 2021, they were still nursing these grievances. As a result they have adopted policies to reduce Pakistan’s influence in their country. Taliban with families and assets in Pakistan were pressurised to repatriate them to Afghanistan. They have also redirected Afghanistan’s trade so that, by 2025, Iran had replaced Pakistan as the main source of Afghanistan’s imports. Meanwhile India has replaced it as the main destination for Afghan exports.

Since taking power, the Taliban have built their insurgent fighters into coherent national security forces – but forces that are subject to intense religious indoctrination. Anticipating the current conflict, they built a series of underground storage facilities for weaponry and to shelter their leaders if required. For now, they rely on vehicle-mounted heavy machine guns as air defence, but they continue trying to acquire more advanced capabilities, for example by showing up at Russian arms exhibitions.

Risk of escalation

If the Taliban were dancing to Islamabad’s tune, they would have answered Pakistan’s call to help deal with the TTP insurgency. Instead, the Taliban has sheltered the TTP allowing them to conduct attacks against Pakistan, despite repeated Pakistani protests and airstrikes against TTP targets in Afghanistan.

But in the fighting since the end of February, Pakistan has escalated from bombing the “guests”“ – TTP targets in Afghanistan – to bombing the “hosts” – the Afghan Taliban. So Afghanistan’s Taliban government has escalated by openly sending Afghan fighters across the border.

The war in the Persian Gulf rapidly overshadowed the Taliban’s war with Pakistan. But that does not diminish the potential for serious consequences from the latest twist in Afghanistan’s conflict. By openly allying themselves with a movement which seeks the overthrow of Pakistan’s government, the Taliban pose a threat to the stability of the second most populous Muslim majority state – a country with a nuclear arsenal.

And this, in turn, increases pressure on the Pakistan army to expand its campaign against the Taliban, contemplating regime change if the regime cannot be reformed. But regime change would require an alternative to the Taliban, which does not currently exist. This suggests that achieving Pakistan’s objectives will require more ambition than yet seen in the air campaign.

The Conversation

Michael Semple has received European and UK government funding for his research on the Taliban

ref. What’s behind Pakistan’s war with Afghanistan’s Taliban government? – https://theconversation.com/whats-behind-pakistans-war-with-afghanistans-taliban-government-277105

The News from Dublin: Colm Tóibín’s latest short story collection resonates with emotional truth

Source: The Conversation – UK – By Manjeet Ridon, Associate Dean International, Faculty of Arts, Design & Humanities, De Montfort University

Colm Tóibín’s latest collection of short stories delivers a quietly powerful collection of nine stories that traverse Ireland, Spain, Argentina and the US. The News from Dublin offers intimate portraits of people shaped by history, disappointment, tragedy, grief and the long shadows of secrecy. These narratives favour restraint over spectacle, revealing emotional truths through subtle gestures, silences and missed connections.

Several stories are rooted in Ireland’s past, foregrounding families and communities under pressure. The Journey to Galway, set during the first world war, follows a mother travelling by train to deliver the telegram announcing her son’s death to his wife, and the impact of the war on the home front.

The drama lies not in external events but in her internal reckoning with grief, duty and the weight of carrying devastating news that will shatter the lives of her family and grandchildren. Tóibín’s spare prose mirrors the emotional austerity of the moment, highlighting how tragedy reverberates through ordinary lives.

A Sum of Money similarly explores Irish social realities, focusing on poverty and moral ambiguity. The young protagonist’s thefts at a religious boarding school are portrayed with empathy rather than condemnation, revealing how deprivation and shame can warp childhood.

The muted reaction when he is discovered and expelled from the school underscores a recurring motif in the collection: the unsaid, the unresolved, and the quiet accommodation of wrongdoing within institutions and families.

In the titular story, The News from Dublin, a schoolteacher’s attempt to navigate the complexities of local politics to secure experimental treatment for his sick brother results in him returning home unable to deliver the much hoped-for news. The absence of “news” is itself the story’s emotional climax, reflecting the moral complexities of familial duty, disappointment and avoidance.

Beyond Ireland, Tóibín examines themes of migration and displacement. Five Bridges follows an undocumented Irish immigrant in San Francisco returning to Ireland after three decades in the US.

His last weekend with his American daughter becomes a poignant reckoning with belonging, fatherhood and the precarity of immigrant life, framed against the spectre of contemporary US immigration raids and law enforcement under Donald Trump’s second term as president. The story captures the solidarity and belonging of diasporic and expatriate communities living precarious lives.

Sleep and Barton Springs delve into grief and sexuality with subtlety. In Sleep, a gay man’s relationship with his lover falters under the strain of his unresolved grief about his deceased brother, prompting a journey back to Dublin for therapy. The story delicately probes how cultural identity shapes the articulation of pain and trauma.

Barton Springs, the shortest story in the collection, also concerns a man grieving the death of his brother and offers a fleeting, sensuous moment of connection amid grief when one swimmer is transfixed in admiration of the physical beauty of another.

The Spanish stories in the collection introduce broader political and historical dimensions. Summer of ’38, narrated by an elderly Marta, reflects on a youthful affair during the Spanish civil war and the lifelong consequences of concealed parentage. Her silence about her daughter’s father encapsulates the collection’s recurring tension between truth and secrecy.

A Free Man, set in Barcelona, is perhaps the most unsettling story: an Irish ex-prisoner unrepentant about his crimes attempts to establish a new life in Spain free from detection. The narrative forces readers to confront moral discomfort without offering easy judgement, echoing biblical and existential motifs.

The collection concludes with The Catalan Girls, a novella-length story that presents a richly layered family saga centred on three sisters whose lives unfold across Spain and Argentina. Narrated from the perspective of the youngest sister, Montse, the story examines sisterhood, sibling rivalry, family poverty and the fragile formation of female identity in patriarchal societies.

The story ends with Montse stealing her sister’s Spanish passport so that she may have a life of independence and financial freedom away from her sisters. This act of betrayal becomes a powerful symbol of her self-preservation and defiance.

Across these stories, Tóibín returns to recurring themes: the burdens of history, the complexities of family and sexuality, the scars of poverty and migration, and the quiet tragedies of withheld truths. His prose is measured, empathetic and unsentimental, allowing readers to inhabit moral grey zones without overt authorial judgement.

The News from Dublin emerges as a complex collection of family histories and profound interior lives, rendered with quiet precision and emotional intelligence, and a set of stories that resonate strongly with contemporary political and social concerns.

The Conversation

Manjeet Ridon does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. The News from Dublin: Colm Tóibín’s latest short story collection resonates with emotional truth – https://theconversation.com/the-news-from-dublin-colm-toibins-latest-short-story-collection-resonates-with-emotional-truth-276230

Why hasn’t the US military used force to secure the Strait of Hormuz?

Source: The Conversation – Global Perspectives – By Justin Bergman, International Affairs Editor, The Conversation

The Conversation, CC BY-SA

Since the United States and Israel launched their war against Iran in late February, Iran has retaliated by targeting commercial ships in the Strait of Hormuz, effectively shutting down the narrow channel of water.

It’s caused a global fuel crisis, even though some ships are managing to get through the strait. US President Donald Trump has given Iran an ultimatum to fully reopen the waterway to oil and gas shipments, and called on NATO allies to help in the effort.

We asked naval expert Jennifer Parker, who served for 20 years with the Royal Australian Navy, to explain what kind of military force would be required to reopen the strait to commercial shipping and why the US hasn’t yet taken this step.

Why is it so hard to prevent attacks on ships?

The geography of the region has a lot to do with this.


The Conversation, CC BY-SA

Iran clearly dominates the northern part of the Persian Gulf, the Strait of Hormuz and the Gulf of Oman. That proximity allows it to use its cheaper weapons such as drones to target ships.

Creating the conditions to make merchant shipping safe – or at least reduce the risk – requires a two-phase campaign.

The first phase is taking out Iran’s ability to target ships. There are two ways to do this:

  • persuade or force Iran to stop attacking ships
  • destroy Iran’s ability to attack ships by taking out its radar facilities, command and control structure and weapons bunkers along the coast.

The US has air power, intelligence, surveillance and reconnaissance capabilities to identify and destroy most of these targets. Locating and destroying Iran’s masses of drones will be harder, as they can be stored almost anywhere, so intelligence will be crucial here.

The Malta-flagged container vessel Safeen Prestige on fire in the Strait of Hormuz on March 18 after being hit by Iranian explosives.
Copernicus Sentinel-2 satellite, CC BY-SA

Once you reduce the risk through a bombing campaign, the second element of getting ships back through the strait is a reassurance campaign.

This requires airborne early warning aircraft and maritime patrol aircraft to monitor not only the strait, but also the Gulf of Oman, the Persian Gulf and along Iran’s coastline.

Fighter aircraft would need to be stationed above the strait and gulf, as combat air patrol and helicopters would need to be ready to deploy against attacks, if necessary. And in the water, the US would need to station warships to provide the occasional escort.

If mines are confirmed or even suspected of being in the strait, this complicates things. The US would require an extensive and time-consuming mine clearance operation.

So, why won’t the US try to militarily secure the strait?

There are four key reasons the US won’t attempt to militarily secure the strait without first achieving phase one (taking out Iran’s ability to target ships) — and why it hasn’t been a focus of the campaign thus far.

First, it would divert military assets, such as aircraft, that are needed elsewhere to carry out Trump’s war objectives.

Second, to make the strait safe for shipping, you actually need to secure not just the water, but the land on either side of it. And this would likely require ground forces – or perhaps raiding parties on Iran’s coastline – which would be complicated and risky for the US military.

Third, securing shipping would require a significant number of naval ships. Realistically, you’d need one or two naval ships per escort operation. A convoy any larger than that would be at increased risk of attack, unless the US and Israel have dramatically reduced Iran’s ability to target the ships.

President Trump has ordered reinforcements from two naval groups into the Middle East, consisting of around 4,500 marines and dozens of aircraft.
The Conversation, NYT, Al Jazeera, CC BY-SA

And fourth, the military needs to think about the risk to its assets versus the benefits of opening the strait. A US warship has a crew of more than 200 personnel. Given Iran’s ability to hit ships with uncrewed surface vessels, drones and cruise missiles, is it worth putting those personnel at risk before you’ve reduced the threats from Iran’s coastline?

What about mines in the strait?

This would be a significant challenge. But one thing first: Iran doesn’t actually need to physically lay the mines, it just needs to convince the US and others that it has. This is enough to prevent civilian ships from wanting to transit through the strait.

The possible types of mines Iran may have laid in the Strait of Hormuz, though there has been no clear evidence mining has occurred.
NYT, CC BY-SA

Sometimes mines can be floating on the surface of the water, so they’re visible. Often, though, mines are submerged or moored. The US would need to send in divers or remote-controlled vehicles launched from ships to remove them. This would take weeks or perhaps even months.

Although it’s not been confirmed publicly, I think it’s unlikely Iran would extensivley lay mines. There are two reasons for this.

First, Iran’s economy relies on its ability to ship its own oil from Kharg Island in the Persian Gulf through the strait. Iran does have other ports outside the strait, but they can’t accommodate bigger ships, so mining would interfere with their trade.

Second, some reports have suggested Iran has used acoustic mines, a type of influence mine that detonates based on an acoustic “signature”, essentially what a ship sounds like as it moves through the water. While this technology certainly exists, it is unlikely such mines would be designed to reliably differentiate between Iranian-flagged merchant vessels and those flagged to other countries.

Maintaining accurate and comprehensive signature data for large numbers of commercial vessels — particularly in a dense and dynamic shipping environment such as the strait — would be extremely challenging. In practice, these mines would pose risks to a wide range of shipping.

The US also has significant intelligence assets and surveillance and reconnaissance systems along the Iranian coast, so it would likely detect mine-laying operations, although this can also occur from any vessel, including fishing boats.

And what about Iran’s ability to target ships with drones?

Iran has used different types of drones so far in the war. The uncrewed aerial craft or uncrewed surface vessels are remotely controlled and have been used to hit merchant tankers.

Compared with other weapons, such as missiles, it’s much harder for the US and Israel to target Iran’s drones on the ground because they can be launched from almost anywhere. And while they can’t be built anywhere, drones don’t require the same advanced manufacturing facilities as missiles. In short, they are harder to detect and wipe out.

But the US can bomb some of Iran’s launching points and drone stockpiles along the coast to prevent some attacks on ships.

What is the main priority for the US in Iran right now?

Although there has been much debate about regime change, the Trump administration has been clear about its four key military objectives, which are to destroy:

  • Iran’s ballistic missile capability
  • its nuclear capability
  • its navy (which has largely been achieved)
  • and its proxy networks, including Hezbollah in Lebanon, which has been under attack by Israel for the past several weeks.

The destruction of Iran’s nuclear and ballistic missile capabilities requires significant aircraft and weaponry – as the US and Israeli bombing campaigns have already made clear. Diverting these assets to secure the Strait of Hormuz could undermine the achievement of these military objectives.

The Conversation

ref. Why hasn’t the US military used force to secure the Strait of Hormuz? – https://theconversation.com/why-hasnt-the-us-military-used-force-to-secure-the-strait-of-hormuz-279224

Is lighter sleep a normal part of ageing – or a sign of something more serious?

Source: The Conversation – Global Perspectives – By Elena Urrestarazu Bolumburu, Consultor Clínico. Servicio de Neurofisiología Clínica. Unidad de Sueño., Universidad de Navarra

Microgen/Shutterstock

As you get older, it’s normal to notice changes in your sleep. These can include fewer hours of shuteye, waking up more during the night, and finding it harder to drop off. However, despite the general view that older people tend to need less sleep, scientific evidence suggests that this change isn’t actually a question of needing less rest, but of a reduced ability to fall into a deep, continuous sleep.

Older brains still need to rest, but they find it harder and do it more superficially. It’s as if the “off switch” that keeps us asleep works less effectively as time goes on.

Lighter sleep and ageing

One of the main reasons we get worse sleep as we age is the loss of stability in the system that regulates sleep and wakefulness.

In the young brain, this system functions like a firm switch: it is either awake or asleep. But as we get older, some neurons that promote and maintain sleep are lost, while others that sustain wakefulness also get weaker. As a result, the brain shifts states more easily, leading to lighter and more fragmented sleep.

Our biological clocks also change with age. The group of neurons that coordinates the entire body’s circadian rhythms (known as the suprachiasmatic nucleus) continues to function, but its “day” becomes shorter and starts earlier, and its signal becomes less intense.

This partly explains why older people tend to fall asleep and wake up earlier. It also explains why their night-time sleep is more sensitive to external stimuli, and why they can experience more drowsiness during the day. Put simply, the brain receives a less clear signal about when to sleep and when to stay awake.

Another significant change is in our “sleep pressure”. This urge builds up throughout the day and causes us to sleep at night, and depends on a substance known as adenosine. As we age, the brain continues to accumulate fatigue but responds less effectively to this signal. Although the need for sleep remains, it becomes more difficult to translate the signal into deep, uninterrupted sleep.

Deep sleep, which is essential for brain recovery, is also directly affected by structural changes in the brain. This phase of sleep occurs primarily in the frontal regions, which lose thickness and connections as we age. As a result, the slow brainwaves that characterise deep sleep become weaker and less frequent – especially at the start of the night.




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During sleep, the brain also sends out brief signals that help consolidate memories from the day. As we age, these signals diminish and become less synchronised with deep sleep. This contributes to a decline in learning and memory efficiency, even in healthy older people.

Finally, ageing affects the connections that enable different regions of the brain to work in sync during the night. Although the neurons that generate sleep are still present, their signals are transmitted less effectively. The result is less deep, more fragmented, and less restorative sleep.

It is important to note that lighter sleep is considered part of the brain’s natural ageing process in healthy older adults. These changes do not necessarily lead to cognitive problems.

Lifestyle factors

In addition to these biological changes, other factors can have a decisive influence on sleep in older people, and often interact with neurobiological mechanisms. For instance, the loss of daily routine – such as regular working hours, structured physical activity and consistent exposure to natural light – weakens the external cues that help synchronise the biological clock, exacerbating sleep fragmentation.

At this stage of life, sleep disorders such as insomnia and obstructive sleep apnoea are more common. At the same time, a greater burden of chronic conditions – persistent pain, cardiovascular or respiratory diseases – and mood disorders leads to additional night-time awakenings and breaks up sleep.

While essential, frequent use of medicines can also disrupt sleep patterns. These range from sleep aids and anxiolytics that affect deep sleep, to antidepressants, beta-blockers and diuretics that interfere with the onset, stability or continuity of sleep.

Taken together, these factors act as modulators. While they do not in themselves cause sleep ageing, they can exacerbate it, and make it clinically significant when they occur in a brain that is already more vulnerable.




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What is “normal” sleep ageing?

In recent years, there has been a growing body of evidence regarding the harmful effects of sleep deprivation and sleep disorders on brain health. Poor sleep is not only associated with poorer cognitive performance in the short term, but also with a higher risk of cognitive decline and dementia in the long term.

This growing interest has placed a spotlight on sleep in old age, a stage of life where sleep patterns almost universally change. However, one of the greatest challenges is to draw a clear line between changes in sleep that are part of normal ageing – meaning they don’t entail any negative physical or mental consequences – and those that may constitute an early, subclinical symptom of neurodegenerative processes.

As they age, a person might begin to notice a deterioration in their sleep patterns (waking up during the night, more superficial sleep, and so on). But there are no biomarkers that can determine whether these are normal changes to be expected with age, or whether they are in fact a manifestation of neurodegenerative disease.

Although it’s normal for sleep to become lighter with age, some changes go beyond what is to be expected and may indicate unhealthy brain ageing. One of the main warning signs is marked and progressive sleep fragmentation, with multiple prolonged night-time awakenings and a persistent feeling of non-restorative sleep, even when the total time spent in bed is enough. Unlike normal ageing, in these cases sleep loses its stability and continuity.




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Another key sign is the rapid onset or worsening of excessive daytime sleepiness, particularly when it interferes with daily activities or is disproportionate to the amount of sleep obtained. This would suggest that a person’s sleep has lost its restorative function.

When should you worry?

From a neurocognitive perspective, the coexistence of sleep disturbances with subtle cognitive changes – such as recent difficulties with memory, attention or learning, even if these do not yet meet the criteria for cognitive impairment – is particularly concerning. Recent research suggests that this combination may reflect early-stage neurodegenerative processes.

Changes in quality of sleep, rather than simply a reduction in sleep duration, are also considered warning signs. This can mean the almost complete disappearance of deep sleep, a marked reduction in REM sleep, or a progressive reversal of the sleep-wake cycle, with increased night-time activity and daytime sleepiness. These patterns are not typical of healthy ageing.

Other warning signs are a growing dependence on medical sleeping aids or sedatives to sleep, as well as treatments that previously worked becoming suddenly ineffective. In these cases, the problem is usually not just insomnia, but an underlying disturbance of the brain’s sleep mechanisms.

These signs alone are not sufficient to diagnose a neurodegenerative disease, but they do show why we need to assess sleep as a potential early risk marker, especially when the changes are recent, progressive and associated with cognitive impairments.


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The Conversation

Elena Urrestarazu Bolumburu no recibe salario, ni ejerce labores de consultoría, ni posee acciones, ni recibe financiación de ninguna compañía u organización que pueda obtener beneficio de este artículo, y ha declarado carecer de vínculos relevantes más allá del cargo académico citado.

ref. Is lighter sleep a normal part of ageing – or a sign of something more serious? – https://theconversation.com/is-lighter-sleep-a-normal-part-of-ageing-or-a-sign-of-something-more-serious-278836