Category: The Conversation

Source: The Conversation – UK – By Zander Simpson, PhD Candidate in Anthropology, Durham University

Editor’s note: The UK’s Food Standards Authority and Health Security Agency both advise against eating clay, soil or earth. Links to their guidance are included in this article.

When I ask people if they have ever eaten soil before, they tend to give me a strange look. But geophagy – the deliberate ingestion of any kind of soil – is a practice that archaeological evidence from Kalambo Falls in Zambia suggests has been part of human history for at least 2 million years.

British archaeologist John Desmond Clark reported that Homo habilis, a species of human who lived between 2.2 and 1.6 million years ago, was digging into the earth to mine clays from below the topsoil. This led to the inference that the oldest evidence of geophagy by humans was at that prehistoric site on the border of Zambia and Tanzania.

More recently, anecdotal evidence suggests a prisoner condemned to death in 16th-century Hohenlohe (now part of Germany) was allowed a last request of consuming a small clay tablet after receiving his supposedly lethal dose of mercury. The tablet was reputedly a piece of terra sigillata – clay traditionally mined from the Greek island of Lemnos. To the amazement of the court, the convict survived the mercury poisoning and was merely banished instead.

Geophagy is still practised widely around the globe, including by some women experiencing food cravings during pregnancy. But it should not be confused with the eating disorder pica.

In my research on geophagy practices in the UK, clays appear to be the most popular types of soil consumed. But these are only a sliver of the many types of soil people are known to eat.

In Amsterdam’s Museum of Edible Earth, researcher and artist masharu has brought together more than 600 soils used in geophagy. These include melt-in-the-mouth pemba from Surinam and montmorillonite green clay from France, which is claimed to be an anti-ageing treatment.

The museum is now in the UK for the first time. Adult visitors to Somerset House in London are being invited to sample a “tasting menu” of its soils, and even contribute their own tasting notes.

The symbolism of soil

For many people, eating soil carries deep symbolic meaning. Soil is a common theme in genesis stories that describe how a people originated, including Adam in the Bible’s Old Testament.

Among the Luo people in Kenya, women who practice geophagy during pregnancy prefer eating red clays due to the links between soil, fertility and blood. These clays are understood to replenish the blood lost during pregnancy to the unborn foetus, which is referred to as remo ma ichweyogo nyathi (the blood you form the child of).

In the 20th century, eating soil was sometimes used to determine guilt in Java. If a crime was committed with no witnesses and the cross-examination failed, suspects would ingest a small amount of soil from their ancestors’ graves and call upon them as witnesses to their innocence. If one of the suspects grew ill or died over the next few months, they would be found guilty.

Today, thinly sliced clay from Java is still eaten as a snack known as ampo.

Soil’s growing appeal

The benefits and risks of eating soil have been highlighted amid recent social media interest in geophagy, such as the trend for filming soil taste tests on TikTok.

A collaboration between researchers at the universities of Glasgow, Strathclyde and Crete suggests clays from Lemnos may have wider health benefits, such as preventing the progression of inflammatory diseases (although, so far, only shown in mice).

Bentonite, which is also used in cosmetic face masks, was mentioned as a favourite edible clay by some customers of a London health-food shop I spoke to.

One reason clays such as bentonite appear to be a popular choice is that they can host Streptomyces, a genus of bacteria that, alongside being a useful source of antibiotics, produce geosmin. This chemical emits the pleasant smell associated with dry earth after rainfall – and also contributes to a pleasantly “earthy” taste.

But any kind of soil should always be consumed with caution. In 2013, Public Health England identified calabash chalk as a particular risk for pregnant women. Its warning was triggered by widespread consumption of this chalk within some Asian and African communities in London, as a nutritional supplement or morning sickness antidote, and the potential threat posed by lead present in some of these soils.

The UK Food Standards Authority has also warned about the presence of lead and other toxic chemicals in commercially available clays.

Some soils may contain hidden dangers such as heavy metals pollutants, parasitic worms and cancer-causing moulds. Additionally, faecal contamination of soils may introduce bacteria such as E coli, which can cause food poisoning.

While these health risks do not apply to all soils, and some of these concerns can be addressed through the way clays are processed, it is advised that anyone interested in practising geophagy should seek careful guidance first.

The exhibition of edible soils by masharu, on show in London until April 26, seeks to challenge the stigma and negative perceptions around eating clay by focusing on the often-overlooked sensations of soil. From environmental science to health research, soil is no longer being treated like dirt.

Zander Simpson receives funding for his research from the Economic and Social Research Council in the form of a PhD Studentship.

– ref. Why do some people eat soil? From a prisoner’s lifeline to a modern tasting menu, the history of geophagy – https://theconversation.com/why-do-some-people-eat-soil-from-a-prisoners-lifeline-to-a-modern-tasting-menu-the-history-of-geophagy-278691

Source: The Conversation – UK – By Dipa Kamdar, Senior Lecturer in Pharmacy Practice, Kingston University

When Lady Gaga recently spoke in an interview about taking lithium while suffering from a “psychotic break”, it drew attention to a drug that has long been used in psychiatry but is less widely understood outside it.

Lithium has been used in psychiatric care for more than 70 years, most notably to treat bipolar disorder. Alongside this renewed attention, a recent study has explored whether much lower doses of lithium might help protect the ageing brain – raising questions about whether its effects could extend beyond mental health treatment.

But the science tells a more complicated – and more sobering – story.

Lithium is a naturally occurring chemical element, found in soil, rocks and water. Most people consume tiny amounts of it through drinking water and foods such as vegetables and grains.

In medicine, it is prescribed in the form of lithium carbonate or lithium citrate. At the doses used in treatment, it steadies mood by reducing how often and how severely manic and depressive episodes occur.

It is also one of the few psychiatric medicines shown to reduce the risk of suicide. In the UK, lithium is licensed for bipolar disorder, mania, severe depression and some forms of aggressive or self-harming behaviour.

Despite decades of use, scientists still do not fully understand how lithium works. What is clear is that it acts across multiple systems in the body at once – affecting brain chemicals such as serotonin and dopamine, helping the immune system function more evenly, and helping to regulate the body’s internal clock.

It may also slow some of the processes associated with ageing at a cellular level, including protecting the structures at the tips of chromosomes that tend to wear down over time, and supporting the tiny structures inside cells that generate energy. In the brain, these combined effects appear to make nerve cells more resilient to stress and damage.

This has led researchers to explore whether lithium might have a role in diseases where the brain gradually deteriorates, such as Alzheimer’s.

An animal study published earlier this year found that when lithium levels in mice were experimentally reduced, the animals developed more of the protein build-ups – amyloid plaques and tau tangles – that are closely associated with Alzheimer’s disease, along with faster memory decline. When lithium levels were restored, these changes were prevented. The findings are promising, but they have not yet been confirmed in humans.

Human studies have produced more cautious results. One trial found that a dose of just 300 micrograms of lithium – far below the amounts used in psychiatric treatment – was linked to slower memory loss in people with Alzheimer’s disease.

Another two-year trial in older adults in the early stages of memory problems found that low-dose lithium was safe, and that memory fared slightly better in those taking it than in those given a placebo. The difference, however, was too small to be considered reliable by the standards researchers use to judge whether a result is real or down to chance.

A 2023 review also noted that areas with higher levels of lithium in drinking water tend to report lower rates of Alzheimer’s disease, although the results varied considerably across studies.

The same review suggested that low-dose lithium might have broader effects beyond the brain, with possible links to heart health, muscle loss, bone thinning and type 2 diabetes. The researchers were clear, though, that the evidence is not yet strong enough to draw firm conclusions.

Lithium as a supplement

So what about taking lithium as a supplement? This is where the picture becomes less clear, and where the risks become more important to consider.

Lithium has what pharmacologists call a “narrow therapeutic window”. In plain terms, this means the gap between a dose that helps and a dose that harms is unusually small. People prescribed lithium require regular blood tests to check that levels in the body remain safe, and to keep an eye on kidney and thyroid health. Without medical supervision, none of that monitoring is likely to happen.

Lithium is processed by the kidneys and can build up in the body, particularly in people who are dehydrated or eating a low-salt diet. It also interacts with a number of commonly used medicines, including anti-inflammatories such as ibuprofen, blood pressure treatments such as Ace inhibitors like ramipril, and water tablets such as indapamide.

These interactions can push lithium levels higher in unpredictable ways, even when the dose being taken seems small. Too much lithium in the body can cause trembling, confusion, vomiting and, in serious cases, seizures.

Many of the low-dose products sold online contain a form called lithium orotate. This is different from the forms prescribed by doctors and is not held to the same safety and quality standards as prescription medicines. There are no large human trials directly comparing it with lithium carbonate or citrate.

Some doctors prescribe low-dose lithium orotate for mood symptoms that do not meet the criteria for bipolar disorder, but this is not backed by strong clinical evidence. Online, it is often sold with sweeping claims about mood, behaviour and memory that go well beyond what the research currently shows.

It is also worth being clear about what Lady Gaga actually said. She described taking prescription lithium – a regulated medicine used under medical supervision – not an over-the-counter supplement. The two are not the same thing.

Research into low-dose lithium and brain health is ongoing, and the early findings are worth watching. But early findings are not the same as answers.

Until large-scale trials show clearly that low-dose lithium is both safe and effective, taking it without medical guidance carries real risks – risks that are easy to miss when the focus falls on the possible benefits. Lithium is a genuinely important medicine. That is precisely why it should not be treated as a casual addition to a supplement routine.

Dipa Kamdar 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. Lady Gaga says she took lithium after a ‘psychotic break’ – here’s what the science says about this drug – https://theconversation.com/lady-gaga-says-she-took-lithium-after-a-psychotic-break-heres-what-the-science-says-about-this-drug-278169

Source: The Conversation – UK – By Jessica Newberry Le Vay, Senior Researcher in Climate Change and Health, University of Oxford

The mental health effects of climate change are receiving growing attention, including how children and young people are uniquely affected. Supporting young people to build and sustain good mental health and wellbeing, and to feel prepared for life and work in an uncertain world, has never been more urgent. However, action is still lagging behind need – including in education.

My colleagues and I at the Compass Project, coordinated by the Climate Cares Centre at the University of Oxford and Imperial College London, are exploring how combining climate change education with consideration of mental health and wellbeing can better equip young people for their futures.

We wanted to know how students and educators experience climate change education now, and what they want to see change. Through focus groups and a survey, we heard from over 200 students aged 16-29 and their educators in schools, further education and sixth form colleges and universities in England. They told us why and how emotional resilience – the social and emotional skills to build and sustain good mental health and wellbeing in the face of challenges – should be part of climate change education.

Status quo: disconnected and disempowered

For many young people, climate change education is disconnected from solutions, and from what they see as helpful to everyday life and enjoy learning about. Students report lacking agency, meaning they don’t feel they have the ability to make change. These are not only barriers to meaningful climate change education. Our study highlights this is also driving both distress and disengagement, and missing opportunities to protect and promote mental health and wellbeing.

Students described a wide range of emotions associated with climate change, including worry, fear, guilt, anger and powerlessness. We heard that education can exacerbate these feelings. One university student said:

[My education] increases my worry because despite being a biology course, and many of my modules being based around ecosystems, the environment, animal behaviour, climate change is not a central theme or something brought up regularly in my learning.

What surprised me was just how much students spoke of climate denial and disengagement, mental health stigma, and stigma around engaging with climate action. Students highlighted these as barriers to discussion and community building. One said:

There seems to be a passive feeling amongst my age cohort and, despite most accepting the truth of climate change, they feel removed and disempowered. This is obviously quite demoralising.

Educators spoke of feeling unsupported and lacking time and resources when it came to teaching about climate change and navigating diverse emotional responses. “We want to teach about climate change,” one said, “but there’s anxiety for the educator to say, what if I set some sort of chain reaction of concern amongst these children, how do I deal with that?”

Such experiences have been reflected through a film by the Climate Majority Project, highlighting the emotional reality of climate change education through the eyes of a teacher.

Change is possible, and already underway

Students and educators had clear, aligned, views on action to better prepare young people for a climate-changed future. This included strengthening connection with nature and curriculum reform to include psychologically informed climate change education in every subject.

Students wanted support to cope with their emotions, and opportunities to take part in meaningful and collective climate action. More time, funding, training and support for educators underpins these actions. A school student said:

It gets to a point where it’s like, this statistic, this statistic. These animals are dying. This country’s just had a flood. If you give [young people] concrete ways, more opportunities to do things that genuinely would help a lot of people, and it also does help the environment, but it takes away that powerlessness and frustration and fear.

Many initiatives are already putting these actions into practice, alongside a growing bank of resources on how to do so.

I was struck by examples students and educators gave of initiatives that did anecdotally support climate change education and build emotional resilience, but hadn’t been designed this way. Inter-school climate action competitions built community, agency and joy. General peer support systems for university assignments led to discussions about climate emotions.

Insufficient attention on the links between climate change education and mental health and wellbeing may mean wider, perhaps unintended, benefits of what schools, colleges and universities are already doing are missed. Particularly given scarce resources and overburdened educators, learning about and investing in how to enable these positive ripple effects – and consistently embed such practices across the education system – is a crucial opportunity.

The transformational societal changes that the climate crisis demands can only take place by considering the emotions, thoughts and beliefs that shape our actions, including support to minimise burnout. Our actions, in turn, shape our emotions and can influence our health and wellbeing. Recognising and resourcing these connections in education systems is critical to truly equip young people for life and work in a changing climate.

Jessica Newberry Le Vay leads the Compass Project, which is funded by the Robert H. N. Ho Family Foundation Global. She works for the Climate Cares Centre based at the University of Oxford and Imperial College London.

– ref. Why emotional resilience should be at the heart of climate change education – https://theconversation.com/why-emotional-resilience-should-be-at-the-heart-of-climate-change-education-275610

Source: The Conversation – UK – By Hossein Hashemi, Senior Lecturer, Division of Water Resources Engineering & Centre for Advanced Middle Eastern Studies, Lund University

In recent years, residents of Spain, France and the UK have looked up to see an eerie sight: deep orange sunrises and skies thick with a yellowish haze. These hazy skies often deposit “blood rain”, rust-colored precipitation that leaves a fine grit on cars and windows.

These events are caused by dust plumes from the Sahara desert that travel thousands of kilometres across the Mediterranean. As climate change alters the world’s largest desert, Europe is finding itself increasingly downwind of a shifting environmental crisis.

The Sahara accounts for more than half of the world’s total dust emissions. Under hot, dry and windy conditions, particles are lifted several kilometres into the atmosphere and transported across continents.

While most travels west toward the Americas, some moves north towards Europe, particularly between February and June. Recent plumes – such as the intense “Calima” that sometimes blankets Spain – have reached as far as the North Sea and Scandinavia.

The relationship between a warming planet and dust is complex.

On one hand, rising temperatures dry out soils and accelerate desertification, making it far easier for wind to dislodge fine particles. Under extreme warming scenarios, the amount of Saharan dust lifted into the atmosphere could rise by 40% to 60% by the end of the century.

However, the “dustiness” of the future also depends on wind patterns. Certain Saharan sand and dust storms have actually become rarer and less intense over the past two decades. Partly, this is due to an increase in vegetation in the Sahel region at the southern border of the Sahara. But it’s also down to a weakening of surface winds in general, and changes in certain large-scale climate patterns.

Health risks and economic consequences

For Europe, the impact is not just aesthetic. Saharan dust can substantially degrade air quality, pushing levels of invisible particulate matter beyond health guidelines. These fine particles, known as PM10, can penetrate deep into the lungs, triggering asthma and cardiovascular issues. In Spain and Italy, modelling studies suggest Saharan dust may account for up to 44% of deaths linked to PM10 pollution.

Dust also carries other costs. When it settles on snow in the Alps it darkens the surface and makes it less able to reflect sunlight, accelerating melting. It can reduce the efficiency of solar panels and disrupt aviation and road traffic by lowering visibility.

What to do about dust

Responding to this growing cross-border problem means acting both at the source and in affected areas.

In the Sahara and its margins, preventing the disruption of intact soils is critical. Overgrazing, river damming and land abandonment can all increase dust emissions. To stabilise the ground, measures include restoring vegetation, maintaining river flows and protecting the fragile “biocrust” of bacteria, moss and other organisms that bind the top few millimetres of desert soils and form a natural shield against wind erosion.

In Europe, the focus is on being prepared. Early warning systems now provide predictions up to 15 days in advance, allowing health authorities to issue alerts for vulnerable people to stay indoors. Simple measures, from improved building ventilation to creating more urban green spaces, can also reduce exposure.

In decades to come, the Saharan “dust belt” will remain a visible indicator of our planet’s health. But technology and forecasting alone will not be enough to solve the problem.

Dust does not respect borders, so managing it will require stronger international cooperation – and binding agreements – on everything from managing river basins to stop lake beds from drying out, to public health responses across Europe. Whether orange skies remain a curiosity or become a regular feature of European life, governments throughout Europe and Africa must take this shared risk seriously.

Hossein Hashemi 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. Climate change is altering Saharan dust – and Europe is downwind – https://theconversation.com/climate-change-is-altering-saharan-dust-and-europe-is-downwind-278605