Calls for a boycott of the 2026 FIFA World Cup are growing, but how realistic is one?

Source: The Conversation – Canada – By Noah Eliot Vanderhoeven, PhD Candidate, Political Science, Western University

The next major international sporting event, the 2026 FIFA Men’s World Cup hosted jointly by the United States, Canada and Mexico, is already garnering international scrutiny. There have been numerous calls to boycott it.

Calls for a boycott were amplified recently following U.S. President Donald Trump’s threats to annex Greenland from Denmark, prompting soccer officials in Germany and France to broach the possibility of both countries boycotting the tournament.

Both countries’ soccer federations have pushed back against calls to boycott the World Cup for now, although recent events in Minneapolis have heightened concerns about the U.S.’ role in hosting the tournament and what that will mean for visitors.

Former FIFA President Sepp Blatter — who was suspended by FIFA in 2015 and replaced by current FIFA president Gianni Infantino amid a corruption scandal he was later acquitted of — recently voiced concerns over the marginalization of political opponents and violent crackdowns on immigration in the U.S.

The World Cup has historically been an event that brings together fans from across the world. Many fans rely on tourist visas, and ICE is expected to be responsible for security at the World Cup. ICE’s director has refused to commit to pausing the agency’s operations during the tournament.

Human rights groups have raised concerns over whether World Cup visitors will be detained and handed to ICE if they engage in actions deemed critical of the U.S. government.

Boycotts at international sporting events

In the history of international sporting events, boycotts have been far less common than bans.

Austria, Bulgaria, Germany, Hungary and the Ottoman Empire were not invited to attend the 1920 Olympic games after losing the First World War.

South Africa was invited to the 1964 Tokyo Games but saw their invitation rescinded due to apartheid, and only rejoined Olympic competition in 1992. Rhodesia saw its invitation to the 1972 Games rescinded due to its government enacting a white supremacist regime.

Notably, both instances of rescinded invitations to the Olympic Games came after other African nations threatened to boycott the Games if South Africa and Rhodesia were invited to participate.

There were also partial boycotts at the 2022 Beijing Winter Olympics. Several nations announced a diplomatic boycott of the 2022 Winter Olympics to protest China’s mistreatment of the Uyghur Muslims, prohibiting many government officials from attending in an official capacity, while still permitting athletes to compete. Russia has been banned from most major international sports competitions since it invaded Ukraine in 2022.

However, the most famous boycott of an international sporting event occurred in 1980 ahead of the Summer Olympics in Moscow following the Soviet invasion of Afghanistan. More than 60 countries boycotted those Games, led by the U.S. In turn, 19 countries boycotted the 1984 Summer Olympics in Los Angeles, led by the Soviet Union and other Eastern bloc countries.

Yet there has never been a World Cup boycott by qualified teams on political grounds. In 1934, Uruguay famously chose not to travel to the second-ever World Cup in Italy because several European teams, including Italy, declined to travel to Uruguay for the inaugural tournament in 1930.

Prior to the 1966 World Cup, all African teams withdrew from qualifying in protest because FIFA had only allocated all of the teams from Africa, Asia and Oceania one combined place at the tournament. There were calls for Norway to boycott the 2022 Men’s World Cup in Qatar, but they did not qualify for the tournament.

How likely is a boycott?

As of yet, no leaders of major soccer federations have endorsed calls for their country to boycott the tournament, despite pressure from some executives and politicians. It would likely take decisive action from a federation head, akin to the action President Jimmy Carter took prior to the 1980 Summer Olympics in Moscow, to arrive at a country boycotting.

Furthermore, given the relationship Trump has built up with FIFA president Gianni Infantino, the effect of a boycott, or any credible threats of one, on the United States’ immigration policy or hosting responsibilities would likely be rather limited, making a boycott an unpopular decision that may not achieve the desired goal of any boycotting nation.

Infantino attended Trump’s inauguration and controversially awarded Trump FIFA’s inaugural Peace Prize. More recently, he signed an agreement with Trumps’ Board of Peace on behalf of FIFA.

Infantino was also a staunch defender of Qatar’s building practices in the face of heavy human rights criticism and was willing to change FIFA’s policies at the last minute to acquiesce to Qatar’s demands for limited alcohol sales during the 2022 Men’s World Cup.

Trump could still escalate geopolitical tensions enough to spark further boycott discussions. But for now, a boycott remains unlikely, and even credible threats would likely do little to shift Infantino and Trump from the status quo.

The Conversation

Noah Eliot Vanderhoeven 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. Calls for a boycott of the 2026 FIFA World Cup are growing, but how realistic is one? – https://theconversation.com/calls-for-a-boycott-of-the-2026-fifa-world-cup-are-growing-but-how-realistic-is-one-275785

What wearables can (and can’t) tell you about your heart health

Source: The Conversation – UK – By Kevin O’Gallagher, MRC Clinician Scientist and Consultant Cardiologist, King’s College London

Many commonly worn wearables can track useful data about your heart health. Syda Productions/ Shutterstock

Half of people in the UK use a wearable device, such as a fitness tracker or smartwatch. These devices collect data relating to health and physical activity levels – including heart rate, step count and sleep quality. With the emergence of AI, such devices will probably become even more sophisticated – potentially able to diagnose our health problems before our GP.

But while wearables can be really useful when it comes to understanding many aspects of your heart health, they still have many shortcomings – so it’s important not to rely on them for everything.

A key strength of modern wearables is the fact that they record such a wide range of useful data, and track trends over time. This makes them perfect for measuring whether any lifestyle changes you’ve made are working for you, and what effects they might be having. For instance, your wearable can tell you if your health kick has had a measurable affect on your sleep quality or blood pressure.

In addition to measuring step count and physical activity, many of the most commonly worn wearables collect cardiovascular data via photoplethysmography (PPG). This is where a light located at the back of the wearable interacts with tiny blood vessels in the skin to give an estimate of changes in blood volume. These changes can be used to accurately measure heart rate, rhythm and blood oxygen levels.

Many currently available devices are also able to record electrocardiographic (ECG) data. This also records your heart’s electric activity, including heart rate and rhythm.

This is why some wearables, particularly those with ECG technology, could be useful in cardiology consultations.

There are currently limitations to the ECGs a cardiologist would normally use to diagnose heart rhythm issues. These ECG monitors only record heart rhythm data for a limited period, such as 24 or 72 hours. This could mean doctors don’t get a full picture of heart health.

But since many people who own a smartwatch or fitness tracker wear them for many hours of the day and over many weeks, this means their wearable may be recording at the time when cardiac symptoms – such as palpitations – occur. This means wearables may overcome the inherent limitations with clinical ECG recordings.

A person checks their heart rate on their wearable fitness watch.
Wearables may even be able to detect abnormal heart rhythms.
Melnikov Dmitriy/ Shutterstock

For instance, a recent study demonstrated that smartwatches can reliably detect atrial fibrillation (a heart rhythm disorder that increases risk of stroke) in patients at risk of the condition. And wearables can also be useful for regularly and accurately monitoring daytime blood pressure.

So, wearables have the ability to provide data that is highly useful to a cardiologist in helping determine a probable diagnosis. But just how much can we rely on this data?

Wearable limitations

Most wearables that detect blood pressure do so via PPG data, which measures blood pressure differently to an inflatable blood pressure cuff. Wearables may also only provide a blood pressure range rather than absolute results. This means a patient may not know whether their “true” blood pressure is normal or not.

The British and Irish Hypertension Society, which formally validates and endorses cuff-based blood pressure monitors, currently doesn’t have a framework to validate wearables. This means no wearables on the market which provide blood pressure monitoring have been officially validated.

There’s also a lack of standardisation across the market for how different wearables produce data for particular metrics. This means it’s possible different devices could give different readouts – even if they’re looking at the same person. If wearables are to be integrated into the healthcare system in future, then standardised, validated methods would be needed.

There are also potential issues in how wearables are positioned within the market with regard their medical capabilities.

Some are advertised as having medical-grade measuring capabilities. However, the majority of devices on the market have not been approved as medical devices by regulatory bodies. This distinction is important for the average consumer to understand, so they don’t trust the device’s data more than they should.

While wearables can be extremely useful for understanding many aspects of your day-to-day heart health, there’s still much about them that will need to be improved before they become a standard part of cardiac care.

Quality assurance and compatibility across different brands will be key, as will ensuring a patient’s data is both reliable and accessible to healthcare staff on their electronic health records.

These are important issues that must be addressed soon if wearable technology is to become a standard part of NHS treatment by 2035, as outlined in the NHS’s ten-year plan for England.

The Conversation

Kevin O’Gallagher 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. What wearables can (and can’t) tell you about your heart health – https://theconversation.com/what-wearables-can-and-cant-tell-you-about-your-heart-health-273075

Fears about AI taking our jobs are understandable – but harmful

Source: The Conversation – UK – By Abigail Marks, Professor of the Future of Work, Newcastle University

Marko Aliaksandr/Shutterstock

As a professor of the future of work, the question I get asked most often is whether AI is going to take everyone’s jobs.

I hear it from students who worry that their degrees will be obsolete before they graduate. I hear it from office workers watching new tools appear in their software. And I hear it from people working in retail and logistics and hospitality and admin, who all suspect that their jobs put them most at risk.

The issue has become a widespread worry in the workplace. And of course, I understand why people are worried.

Because for a very long time, technology has been sold to employers as a way of achieving more with a smaller workforce. When new tech arrives, it often means cutting costs.

So far though, AI has not led to mass unemployment, and society’s use of the technology is, and will probably continue to be, nuanced and complex.

Yet blunt headlines declaring that “AI will take your job” are hard to ignore. And they can place workers in a passive position, where they end up waiting fearfully to see whether they will be part of the technological cull.

But we also need to be wary of the fear itself. For fear is not just a private and unpleasant feeling – fear changes how people behave and how they relate to society.

Nor is AI-driven anxiety evenly distributed. Some professionals with stable contracts will have the luxury of treating AI as an efficiency tool, something that removes tedious tasks and speeds up routine work.

But others, who work in call centres or data entry, where tasks are repetitive, measurable and tightly monitored, often see AI as something that could remove the substance of their job. For these people, the AI revolution does not feel like an upgrade, it feels like a countdown to unemployment.

And this is why the perceived threat matters. Because even before jobs disappear, the fear of losing them can reshape lives. Research shows that people who believe their livelihoods are at risk are understandably less willing to plan for the future.

They may delay major decisions because they feels pointless or unaffordable. They may disengage from work because they assume loyalty will not be rewarded.

Anxiety goes up, morale falls and the workplace becomes a site of uncertainty.
And then the idea that AI will take over jobs becomes not just an economic problem but also a psychological one.

For work is not simply a way to pay the bills. To many people it is a vital source of identity, dignity and social connection. And when work feels under threat, people can feel personally diminished.

Transparency

After all, if the tasks you have built your life around are suddenly described as something AI could do, it is hard not to infer that your efforts are (and have been) of little value; that you are replaceable and that your contribution no longer matters.

This is where fear turns into alienation, and its effects move beyond the workplace. Over time, that loss of trust can harden into cynicism about society itself.

Anxiety about automation can then blend into wider questions about inequality. And if millions of workers believe they are one software update away from redundancy, that belief can be socially destabilising.

Woman looking thoughtful surrounded by tech graphic.
AI and alienation.
Stock-Asso/Shutterstock

What matters then is how AI is integrated into workplaces, and whether that integration supports people’s ability to keep working on fair and predictable terms. This requires transparency and the involvement of the workers themselves. Above all, it is essential to give those workers a say in how AI affects their tasks, their pace of work, and the metrics by which they are assessed.

Because while AI will reshape work, the future should not be predetermined by the technology itself. And the greatest risk may not be that AI replaces everyone overnight, but that the fear of replacement becomes widespread and corrosive – damaging wellbeing, undermining dignity and building resentment.

So we should absolutely take the threat of AI seriously. But we should also stop treating AI as an unstoppable force, and start treating it as something that can be shaped by society.

And the next time someone asks me whether AI is going to take people’s jobs, I will still answer honestly – that without proper consideration, there is a chance that systems will be implemented which change the way we work and damage personal dignity and economic stability.

But I will also try to address the more important question about what society can do to mitigate this damage – and make sure that the fear of AI doesn’t become a major crisis in itself.

The Conversation

Abigail Marks 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. Fears about AI taking our jobs are understandable – but harmful – https://theconversation.com/fears-about-ai-taking-our-jobs-are-understandable-but-harmful-276245

The Moment: Charli XCX is the ultimate chronicler of contemporary pop stardom

Source: The Conversation – UK – By Alice Pember, Assistant Professor of Film and Television Studies, University of Warwick

“Want to go again?” a choreographer asks Charli XCX at the start of the mockumentary The Moment. It’s the latest entry in the pop star’s rapidly expanding cinematic empire, propelled by the stratospheric cultural impact of her 2024 album, Brat.

He is asking if she’s ready to practise a gyrating, strobe-heavy routine one more time. But this question also gestures towards the central conceit of the film: what if “Brat summer” was pushed beyond its natural expiry date? Not to explore “the tension of staying too long”, as Charli has described it, but in a cynical attempt to further monetise this fleeting moment of pop cultural hype.

Conceived by Charli, The Moment offers a semi-fictionalised mockumentary account of the post Brat summer comedown. It positions her at the centre of several cynical attempts to extend its lifespan through questionable endorsement deals, social media posts and an ill-fated concert film. The film’s events map eerily onto the real post-Brat timeline, inviting knowing audiences to question the boundary between fiction and reality.

Charli’s uncertain response to the choreographer’s question − “Err … yeah?” – from the floor of her rehearsal space (in that starriest of destinations, Dagenham) crystallises the film’s knowing subversion of dominant trends in the female-oriented pop star documentary.

The trailer for The Moment.

As cultural theorist Annelot Prins has outlined in a paper, pop star documentaries like Lady Gaga’s Five Foot Two (2017), Kesha’s Rainbow (2020) and Taylor’s Swift’s Miss Americana (2020) tend to present “empowering narratives of talented and hardworking women who used to be constrained by different factors but overcame them with resilience […] and are now self-determined agents”.

This approach to female celebrity has continued in a recent glut of arena concert films released by stars including Swift, Beyoncé and Olivia Rodrigo. These arena spectaculars combine polished tour footage with backstage glimpses into the creative process. It’s a combination of intimacy and polish engineered to confirm their authentic talent in the face of the relentless commercial demands of the pop world.




Read more:
A swift history of the concert film, from The Last Waltz to the Eras Tour


The “resilient pop documentary” is part of a wider trend identified by feminist media scholars: representations of celebrity women overcoming setbacks such as sexual assault (Kesha), addiction (Demi Lovato) or illness (Lady Gaga).

Feminist sociologist Angela McRobbie’s work shows how these images of “resilient” female celebrities block collective resistance to misogyny, racism and classism, by making women believe they can overcome oppression through “self-management and care”.

This is a pattern that these documentaries repeat with their emphasis on the creative survival of the damaged female pop star. The Moment invokes and satirises these narrative templates by showing Charli’s fictionalised self’s inability to control the runaway momentum of her own stardom.

Resilience to reflexivity

While The Moment has been positioned as Charli’s pivot from pop to the silver screen, it extends the subversions of her oft-forgotten first cinematic venture: 2022’s Charli XCX: Alone Together.

Inverting The Moment’s narrative structure, Alone Together opens with Charli’s preparations for her first arena tour, charting the effects of its abrupt cancellation in the wake of COVID. The remainder of the film depicts Charli’s production of her fourth studio album over the course of a whirlwind six-weeks of the first lockdown.

This ambitious undertaking could have provided the perfect opportunity to emphasise Charli’s resilience, but Alone Together takes a difference tack. It focuses on the emotional toll the album’s production took on Charli and emphasises the digital spaces of care and community that enabled her and her fans to survive the pandemic.

While The Moment and Alone Together approach subversion differently, both knowingly undermine the resilience typically celebrated in pop star documentaries, exposing the endless performance of “overcoming” on which female pop stardom relies. The ending of Alone Together positions Charli as the unmoved consumer of the final album. A post-credit sequence shows her immediately at another loose end. “I just feel a bit, like, bored … What am I going to do now?” she says to camera, laughing.

The trailer for Alone Together.

The Moment’s closing scenes echo Alone Together’s feeling of anti-climax by ending with the trailer for the Brat concert film and its invitation to “be a 365 Party Girl from the comfort of your own home”. Hilariously, this is soundtracked by the Verve’s Bitter Sweet Symphony – an overplayed Britpop anthem that confirms the fictional XCX’s fall from cool in pursuit of mass appeal.

The film’s quasi-documentary style compounds its challenge to the forms of authenticity upon which resilient pop stardom relies. In a voice note to her team, Charli explains that she is completing the film to “kill Brat” and free herself to pursue other creative endeavours. Here, the film uses the intimate framing used to convey authentic agency in the conventional pop documentary. This serves to blur the paper-thin line between the “real” post-Brat hype engineered by Charli and the trite, opportunistic spectacle she embraces in The Moment.

That we are left with no clear sense of what the difference truly is signals that, far from being a “shallow” take on pop celebrity, The Moment turns the conventions of the pop star documentary against themselves. In doing so, the film cleverly exposes the artificiality inherent in even the most seemingly authentic of pop performances.

Taken together, these two films cement Charli XCX’s status as our best chronicler of contemporary female pop stardom and the role of her film texts in exposing the artifice at play in supposedly “authentic” resilient pop cultural performance.


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The Conversation

Alice Pember 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 Moment: Charli XCX is the ultimate chronicler of contemporary pop stardom – https://theconversation.com/the-moment-charli-xcx-is-the-ultimate-chronicler-of-contemporary-pop-stardom-276681

Endometriosis: how a court ruling could make workplaces better for those with the condition

Source: The Conversation – UK – By Aishwarya Viswamitra, PhD Researcher, School of Applied Social Sciences, De Montfort University

fizkes/Shutterstock

Sanju Pal built a successful career in management consulting, winning major awards and working at a senior level. Then her health changed.

After being diagnosed with severe endometriosis and undergoing surgery, she returned to work but struggled with pain and fatigue. Months later, she was dismissed for not meeting performance targets. What followed was years of legal action, culminating in a January 2026 ruling that she had experienced discrimination arising from disability under the Equality Act 2010.

Her case may set an important precedent. It also highlights a wider issue: how many others are navigating chronic illness at work without recognition, flexibility or legal support?

Endometriosis is a long-term condition in which tissue similar to the lining of the womb grows elsewhere in the body. It can cause severe pelvic pain, fatigue, heavy bleeding and other debilitating symptoms. For many, the impact on daily life, including work, is significant.

Despite this, diagnosis is often slow. Endometriosis affects 1.5 million women in the UK (one in every ten), and yet the average diagnostic delay is around eight years. During that time, people may continue working while managing escalating symptoms without formal recognition or support.

Pain may be dismissed as normal. Fatigue may be hidden. Without a diagnosis, adjustments at work are difficult to request and even harder to secure.

Work and endometriosis – the research

Evidence consistently shows that endometriosis can shape working lives in significant ways. Some studies suggest that around 38% of people with the condition worry about losing their job because of it. Others report that roughly 35% experience reduced income linked to symptoms. Many describe working through severe pain to avoid triggering absence procedures or being seen as unreliable.

Research highlights a culture of presenteeism and overcompensation. Employees push themselves to meet productivity targets, conceal symptoms and avoid disclosure. Annual leave is often used to manage flare-ups. Some reduce hours, shift into part-time roles or move into self-employment seeking flexibility, sometimes at the cost of career progression and financial security.

Disclosure itself can feel risky. Endometriosis remains poorly understood and is often invisible. Symptoms such as pelvic pain or heavy bleeding can be difficult to discuss in professional settings. Some fear being seen as less capable or less committed.




Read more:
Endometriosis afflicts millions of women, but few people feel comfortable talking about it


Workplaces, meanwhile, are often structured around uninterrupted availability and consistent productivity. Performance models that rely on fixed timelines and metrics may struggle to accommodate fluctuating conditions. When absence policies, promotion criteria and workloads remain rigid, employees can be penalised for symptoms beyond their control.

Sanju Pal’s experience of being assessed against standard progression targets during illness reflects patterns described in this research.

Recognition and its limits

Endometriosis has gained increasing political and public attention in the UK over the past decade. Parliamentary debates, inquiries and awareness campaigns have highlighted the challenges around diagnosis, workplace support and education.

Yet recognition at policy level does not always translate into everyday practice. Under the Equality Act 2010, a formal diagnosis is not required for someone to be considered disabled. What matters is whether an impairment has a substantial and long-term impact on normal daily activities. In some cases, endometriosis may meet this threshold.

In reality, recognition often comes only after lengthy disputes. Tribunals can be stressful, time-consuming and emotionally draining. Not everyone has the resources or stamina to pursue one.

Work is more than income. It shapes identity, confidence and social connection. Research on chronic illness and employment shows that supportive environments can make a meaningful difference. Flexible schedules, understanding managers and open communication can help people stay in roles they value. Rigid systems, by contrast, can intensify stress and push people out of the workforce.

Where workplaces go from here

Endometriosis UK’s Employer Friendly Employer scheme works with organisations to improve awareness and workplace practice. Initiatives like this aim to close the gap between policy and experience.

At the same time, significant questions remain. We know a growing amount about how endometriosis affects employees. We know far less about how employers understand the condition, how they interpret their legal responsibilities and what prevents adjustments from being made.

Cases like Sanju Pal’s should not be seen as isolated disputes. They reveal structural tensions between chronic illness and contemporary work culture, where productivity is often measured through consistency and visibility rather than wellbeing and sustainability.

If workplace equality is to improve, two things are needed. Employers must design systems that anticipate fluctuating health and build flexibility into everyday practice. Researchers must continue producing evidence that highlights the realities of living and working with endometriosis.

The question is no longer whether the condition affects working lives. It is whether workplaces are prepared to adapt before the next employee has to fight a legal battle to be recognised.

The Conversation

Aishwarya Viswamitra receives funding from the Economic and Social Research Council (ESRC).

ref. Endometriosis: how a court ruling could make workplaces better for those with the condition – https://theconversation.com/endometriosis-how-a-court-ruling-could-make-workplaces-better-for-those-with-the-condition-276356

Can a tar-like substance that oozes out of Himalayan rocks really boost your testosterone levels?

Source: The Conversation – UK – By Daniel Kelly, Senior Lecturer in Biochemistry, Sheffield Hallam University

Shilajit, Himalayan rock ooze. StockImageFactory.com/Shutterstock.com

Shilajit is the latest supplement marketed online as a “natural testosterone booster”. Promoted by influencers, wellness brands and biohacking communities, this sticky black resin is advertised as a way to increase testosterone, improve energy and enhance male vitality.

Shilajit is a tar-like substance formed over centuries from decomposed plant material compressed within rock in high-altitude regions such as the Himalayas. It has a long history of use in traditional Ayurvedic medicine, where it has been described as a rejuvenator and as an anti-aging compound.

Chemically, it contains a mixture of fulvic acid and trace minerals. Its complex composition is part of its mystique and also part of the scientific challenge in studying it.

When it comes to testosterone specifically, the evidence for shilajit’s effect on testosterone levels in humans is limited to two small studies.

The most frequently cited study was published in 2016. In this trial of healthy men aged 45–55, half were given purified shilajit (250mg twice daily) and half were given a placebo for 90 days. Neither group knew which group they had been randomly assigned to. The shilajit group saw increases in both total and free testosterone – the form immediately available for the body to use – compared with the placebo group.

On the surface, this sounds encouraging. However, the study included just 38 participants treated with shilajit, was of a relatively short duration, and measured testosterone using methods that are not considered the most reliable.

Although testosterone levels were modestly higher at 90 days, measurements at 30 and 60 days fluctuated in both directions. And probably the most curious finding was that testosterone levels fell in the placebo group, possibly inflating any claimed direct effects of shilajit on hormone levels.

The study was also funded by the manufacturer of the shilajit preparation used. While that does not invalidate the findings, it does warrant caution and independent replication.

An earlier study in infertile men reported improvements in semen parameters and increases in testosterone after shilajit supplementation. But again, sample sizes were modest, with only 28 men taking part – and the population studied was specific to men attending a fertility clinic. These findings may not translate to otherwise healthy men.

Beyond these small trials, there is a lack of large, independent, long-term studies assessing whether shilajit meaningfully raises testosterone in a way that improves muscle mass, strength, metabolic health or quality of life.

It is also important to distinguish between “statistically significant” changes in hormone levels and “clinically significant” ones. Testosterone fluctuates naturally throughout the day and declines gradually with age. Small shifts within the normal physiological range are unlikely to transform body composition or vitality. In both the clinical studies, testosterone was always in this physiological reference range, despite the reported increases.

Another issue that receives less attention in promotional material is product quality and contamination. Because shilajit is harvested from natural rock formations and then processed, its composition can vary substantially. Several analyses of commercially available preparations have raised concerns about contamination with heavy metals such as lead, mercury and arsenic.

While reputable manufacturers may purify their products, the supplement market is not regulated to the same standard as prescription medicines. Consumers are often paying premium prices for products that may differ considerably in purity and potency.

What actually affects testosterone?

Against this backdrop, it is worth asking what actually influences testosterone levels in men.

Sleep is one of the most powerful regulators. Even short-term sleep restriction can reduce testosterone concentrations in healthy young men. Being overweight is linked to lower testosterone, partly because extra body fat can turn some testosterone into oestrogen.

A young man in bed, staring at his phone.
Not getting enough sleep is linked with lower testosterone levels.
Arsenii Palivoda/Shutterstock.com

Resistance training can temporarily increase testosterone and, more importantly, improve muscle mass and regulate blood sugar irrespective of hormone changes. Long-term stress and drinking too much alcohol can interfere with the system in your body, called the hypothalamic–pituitary–gonadal axis, that regulates testosterone production.

In other words, the foundations of hormonal health are behavioural and metabolic. No supplement has yet been shown to override the effects of poor sleep, inactivity, stress or obesity.

For men experiencing symptoms such as persistent fatigue, low libido, erectile dysfunction or reduced muscle strength, the appropriate first step is medical assessment. In clinical practice, testosterone deficiency is diagnosed only after consistent biochemical evidence on repeated morning blood tests, alongside symptoms.

Testosterone deficiency can be associated with underlying conditions including obesity, type 2 diabetes, chronic illness or pituitary disorders. Blood testing, performed correctly and interpreted in context, is essential before considering any intervention.

In men with confirmed hypogonadism (the medical term for low testosterone levels), doctors can safely prescribe testosterone treatment, and there’s good evidence it works in many cases. That is very different from taking supplements you buy online based on marketing claims.

The growing popularity of shilajit sits within a broader cultural moment. Testosterone has become a shorthand for masculinity, energy and success.

Social media algorithms amplify anxieties about “low T”, often without context about what constitutes a true deficiency. Ancient remedies packaged in minimalist jars offer an appealing narrative of being natural, traditional and potent. Add influencer endorsements and promises of optimisation, and the commercial potential is obvious.

The appeal of quick fixes is understandable, but hormonal health is rarely fixed by a resin scraped from a rock. Consumers should also weigh cost against benefit. High-quality shilajit supplements can be expensive, particularly when taken for months at a time. For many men, the same investment directed towards structured exercise programmes, dietary improvements or professional medical advice would probably yield far greater returns.

In the case of shilajit, as with many supplements that promise hormonal optimisation, the marketing has travelled much faster than the science. This does not mean shilajit is entirely without potential.

The preliminary trials justify further rigorous investigation. Larger, independently funded studies could help clarify whether it exerts meaningful endocrine or metabolic effects, and in which populations.

Until then, the current evidence supports curiosity rather than confidence. Hormonal health requires careful assessment. Attempts to manipulate it without proper diagnosis and clinical oversight are unlikely to deliver what the marketing promises.

The Conversation

Daniel Kelly 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. Can a tar-like substance that oozes out of Himalayan rocks really boost your testosterone levels? – https://theconversation.com/can-a-tar-like-substance-that-oozes-out-of-himalayan-rocks-really-boost-your-testosterone-levels-275633

Mexico may pay a steep price for the killing of Jalisco cartel leader El Mencho

Source: The Conversation – UK – By Raul Zepeda Gil, Research Fellow in the War Studies Department, King’s College London

The leader of the Jalisco New Generation (CJNG) cartel, Nemesio Oseguera Cervantes, died in custody on February 22, shortly after he was captured by the Mexican authorities. The operation, which came amid renewed US demands for “tangible results” against fentanyl trafficking, appears to have relied on American intelligence support.

This is the most significant intervention against the cartels since the capture of former drug lord Joaquín “El Chapo” Guzmán in 2016. The CJNG is one of the strongest criminal organisations in Mexico and, alongside the Sinaloa cartel, sits at the centre of US claims about fentanyl production and trafficking.

The killing of Oseguera Cervantes, who is better known as “El Mencho”, may have enabled Mexico’s authorities to secure a political win with Washington. But the operation should not be seen as a victory. What often comes next when the Mexican state removes a high-profile cartel figure like El Mencho is an extended period of violence and instability inside the country.

In my own research on criminal conflict in the Tierra Caliente region of western Mexico, I trace how earlier rounds of arrests and state killings have reshaped local criminal groups, broken alliances and created openings for new players and leaders. It was through this very cycle of state enforcement and cartel reorganisation that El Mencho rose to prominence.

El Mencho began as an operational figure linked to the Valencia cartel, an organisation based in the state of Michoacán. The group lost ground in the late 2000s following sustained pressure from the authorities. After key parts of the Valencia network were dismantled around 2010, El Mencho and other remnants of the group moved to Jalisco further north and founded the CJNG.

The conditions that allowed the CJNG to rise came from the same enforcement repertoire that the authorities have now deployed against it. This pattern matters because it undercuts a common assumption among policymakers, including in US agencies such as the Drug Enforcement Administration, that removing a “boss” equals dismantling a criminal market.

The removal of Mexican criminal leaders does not cause the market for drugs to vanish, nor does it cause trafficking routes to disappear. What changes is the balance of power among groups that already compete for territory, labour and access to ports, roads and local authorities.

Studies that track the so-called “kingpin” strategy, the deliberate targeting of cartel leaders by law enforcement, have found that detentions and killings often trigger short-term spikes in homicides and instability in Mexico. Some work suggests that violence rises for months after a leader’s removal, while other research shows that the killing of a kingpin can provoke a sharper increase than an arrest.

This happens because an affected cartel faces a sudden succession struggle and employs violence to prevent – or respond to – rivals testing the new leadership and trying to renegotiate areas of control. As criminal groups cannot use the formal court system to resolve disputes, they tend to do so through open violence or bargains enforced by coercion.

This logic of violence has already been seen following El Mencho’s death. Reports of cartel gunmen blocking roads, launching arson attacks and carrying out disruptions across multiple states fit a familiar script: an affected organisation signalling its capacity, punishing the state and warning local rivals not to seize the moment.

Even if the state contains this wave of violence, the deeper risk sits in what follows. A leadership vacuum invites internal fracture and external opportunism from rivals who have waited for an opening to test boundaries and settle scores.

The 2024 detention of Sinaloa cartel leader Ismael “El Mayo” Zambada, for instance, has provoked a wave of violence in Sinaloa state as different factions in the organisation battle for leadership.

US drug politics

Another cycle that keeps repeating across Latin America is that US drug politics shapes security agendas throughout the region. A surge in overdose deaths, for example, can lead to political panic in the US and the application of pressure on Latin American governments to take action, usually through militarised enforcement.

These governments respond with crackdowns, raids and high-profile captures. This is followed by rising violence as criminal organisations fragment and then, after a period of time, governments try to deescalate. The cycle starts again when concern over drug trafficking next arises in the US.

Drug prohibition keeps this cycle alive by ruling out any response other than force or criminal law, while failing to produce meaningful results. Most countries have criminalised drugs. But despite governments reporting rising drug seizures each year, deaths linked to drug use globally continue to climb.

Mexico’s security forces cannot end a transnational market that is financed largely by US demand, no matter how many high-profile arrests they make. Operations that result in the killing or detention of cartel figures instead redirect and reorganise the drug trade, while often intensifying violence.

If Mexico and the US want fewer cartel-related deaths, they need to stop treating kingpin killings as the main metric of success. While a high-profile strike temporarily satisfies US pressure, it is Mexican citizens who all-to-often have to live with the blowback of this approach.

The Conversation

Raul Zepeda Gil 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. Mexico may pay a steep price for the killing of Jalisco cartel leader El Mencho – https://theconversation.com/mexico-may-pay-a-steep-price-for-the-killing-of-jalisco-cartel-leader-el-mencho-276648

Scrapping business class could halve aviation emissions – new study

Source: The Conversation – UK – By Milan Klöwer, NERC Independent Research Fellow, University of Oxford

Air travel is famously one of the hardest sectors to decarbonise, and the number of air passengers keeps increasing. Electric planes and “sustainable” aviation fuels are still a long way off making a dent in the industry’s emissions – if they ever will.

But new research by me and my colleagues shows aviation could still cut its climate impact dramatically, simply by using planes more efficiently. In fact, rethinking cabin layouts alone could slash emissions by up to half.

From 1980 to 2019, the share of occupied seats in commercial air planes increased from 63% to 82%. Airlines already have strong commercial incentives to sell every seat – empty ones cost money as well as carbon.

For any given level of passenger travel, carrying more people on each flight means other planes can stay grounded and fewer flights are needed overall. It’s planes that make the big difference, not people – the additional weight of a passenger and their luggage is negligible relative to the aircraft and its fuel.

Aviation is responsible for 2%-3% of global CO₂, but its contribution to global warming is about 4% when secondary effects like condensation trails (which trap heat) are factored in. This impact is dominated by rich people flying frequently, often long-haul in business and first class or even private.

Efficiency in aviation is often thought of as an engineering challenge: how much thrust an engine generates for a given amount of jet fuel. But operational efficiency – the amount of passenger-kilometres per unit of CO₂ emitted – has received far less attention.

In our research, my colleagues and I calculated this operational efficiency for the year 2023, for every flight route, by airline, aircraft model and airport. We found that efficiency gains available in the short term could reduce aviation’s climate impact by more than half.

Short empty flights are the least fuel-efficient

On average, aviation emissions fell from around 260 grams of CO₂ per paying passenger-kilometre in 1980 to 90 grams in 2019. That’s a big difference, but for comparison, electrified rail powered by low-carbon energy can emit less than 5 grams.

Our analysis shows that CO₂ efficiency varies enormously across routes, regions, airports, airlines and aircraft models. Some flight routes emit more than 800 grams per passenger-kilometre, others less than 50. This variability is staggering but also yields a large potential to reduce emissions if efficiency across the industry increased towards that of the most efficient routes we analysed.

Among the highest emitting countries, many of the least efficient flights start or land in the US, followed by China, Germany and Japan. Inefficient flights are common elsewhere, particularly from or to smaller airports, and in Africa and Oceania, often exceeding 140g per passenger-kilometre.

By contrast, more efficient flights – below 100 grams per passenger-kilometre – are common in Brazil, India and south-east Asia, particularly on high volume routes. Europe contains a mix of both.

These differences can be explained by the share of occupied seats, the aircraft models used on a route and the cabin layout – especially the space allocated for business and first class.

Budget airlines tend to be more efficient as they seat as many passengers as possible. Spacious business or first class seats are often removed and revenue is instead generated through services such as baggage, food or booking flexibility – all of which add little to flight emissions.

A view down the aisle of a budget airline plane.
Budget airlines tend to fill their seats.
Katarzyna Ledwon / shutterstock

We also found a few newer aircraft models to be the most efficient in operation (Boeing 787 Dreamliner and Airbus 320neo, both in several variants) averaging less than 65 grams of CO₂ per passenger-kilometre. However, they are not (yet) the most widely used, partly because aircraft typically remain in service for around 25 years.

Long-haul flights are on average more efficient than shorter flights. Take-off emissions only occur once, and larger aircraft with more seats are typically used on longer routes. For similar reasons, larger airports tend to have lower average emissions per passenger.

Increasing air travel efficiency

We modelled three hypothetical scenarios to illustrate the potential of certain operational changes, recalculating the total emissions after each change.

First, we increased the average passenger load factor from 80% to 95%. This alone would cut emissions by 16%, as fewer flights would be needed to carry the same number of passengers. While this is already in airlines’ interests, creating additional incentives – such as emissions-linked airport charges or fuel taxes – could encourage further gains.

Second, we imagined only the two most efficient aircraft (Boeing 787-9 and Airbus A321neo) were in operation. Aircraft cannot be replaced overnight, given their long service lives, and airlines haven’t built enough 787-9 or A321neo yet anyway. But choosing already existing aircraft highlights the potential of replacing older aircraft with newer and more efficient ones – in our calculations, it would save between 27% and 34% of global emissions. This would also require overcoming logical and commercial constraints, again potentially incentivised by airport or fuel charges.

Third, we analysed the impact of an all-economy cabin layout. Business and first class seats are up to five times more CO₂-intensive than economy seating because they occupy far more space per passenger. Operating all aircraft at the manufacturers maximum seating capacity would reduce global aircraft emissions by between 26% and 57%.

There are already large differences between airlines. Some chose to set up their Boeing 777-300 ERs with more than 400 economy seats, while others have as few as 200, despite a maximum seating capacity of 550.

Our findings highlight how strongly aviation emissions are shaped by travel inequality between occasional economy fliers and frequent business and first class travellers. Many of those may complain about the inconvenience of economy class. But perhaps that’s not a bad thing: it could create an even stronger incentive to reduce the number of non-essential journeys.

The Conversation

Milan Klöwer receives funding from the Natural Environment Research Council.

ref. Scrapping business class could halve aviation emissions – new study – https://theconversation.com/scrapping-business-class-could-halve-aviation-emissions-new-study-275474

Loitering without intent: how taking aimless walks can create community and help you feel part of a city

Source: The Conversation – UK – By Morag Rose, Senior Lecturer in Human Geography, University of Liverpool

I love walking, and think it can change the world, but I hate wellbeing walks. I’m more interested in how walking can connect us to the places we dwell and the people we dwell with.

As a disabled person, wellbeing narratives frequently ignore my needs. They assume a standard body and often have a moralistic or bossy tone. They can ignore individual access needs and structural inequalities.

My walking is slow and sometimes painful. It is made possible by the NHS, orthotics (specialised, removable shoe inserts) and wider social infrastructure: from benches to public transport. “Walking” must be inclusive of wheelchairs, orthotics and other assistive technology. I believe everyone should have the right to walk and take up space on the streets.

Walking together can be a powerful way to critically engage with our environment and feel a sense of belonging. I have been exploring this idea in my art, activism and academic research, which has been bought together in The Feminist Art of Walking.

On a monthly basis for almost 20 years I have stood in Manchester and waited to see who will join me for a walk. I share the invitation widely, it’s open to anyone and always free to join. There is a meeting point but scant other information.

I can’t tell anyone where we will go since I simply don’t know our destination. When folk arrive, and they always do, we drift, guided by paper planes or pigeons, DIY maps or culverted rivers, our senses or our hearts. Every month a different prompt or provocation to inspire our wandering.

My waiting, and walking, began as an activist experiment, a way to subvert city streets increasingly threatened by gentrification, homogenisation and privatisation. I believe public space, non-commercial open places, where people can gather, ask questions, start conversations, or simply just be, are vital. We need to expand what we mean by public space to include pavements, bus stops, plazas and the like. We must resist attempts to prescribe, prohibit or limit access to such places. This matters now more than ever.

Opening up, sharing stories, making, holding, extending space – walking together with respect for those we share that space with – is the opposite of planting a flag and claiming dominance.

I wanted to explore ideas around psychogeography, an idea originated by the Marxist theorist Guy Debord in 1955 that asked how different places make us feel and behave. In response, I co-founded the LRM (Loiterers Resistance Movement).

Loitering for me means slowing down, resisting the need for productivity. Not everything of worth can, or should, be measured, commercialised or turned into an “output”. That’s why our events have always been free for everyone. Loitering also celebrates playfulness and re-enchantment. The LRM’s manifesto says:

We believe there is magic in the Mancunian rain. Our city is wonderful and made for more than shopping.

The beautiful thing about walking this way is the serendipity, the conversations and encounters. Over the years a community has formed and together we share stories and walk ourselves into being part of the city.

One of the aims of the most recent LRM walk was to gently challenge fear. We used warning signs and prohibition notices as our catalyst. Snow on the pavements added a personal dimension as my navigation was also informed by minimising the risk of slipping. My world shrinks in the snow, so an additional guiding element was added, a heightened awareness of textures and shadows. I was struck by the care of the collective, everyone kept pace, tracing thaw patterns and seeking clear patches.

Psychogeography suggests using the body as a tool to investigate the urban landscape and better understand the invisible power lines of commerce and capitalism. The psychogeographer uses the drift to free themselves from the everyday and walk new routes, with the intention of providing an alternative vision of the city.

Historically, the psychogeographer became associated with the “flaneur”, a lone male wanderer who is able to move unheeded through the city. This romantic idyll doesn’t reflect the reality for many of us, and there are many barriers stopping folk.

In my own research, I have walked with women across Manchester whose movements are shaped or limited by gendered street harassment, or the justified fear of violence. This can be compounded by intersectional factors such as race, faith, age or sexuality.

Of course women resist and still walk despite threats. As well as everyday walking, this can be seen during protest walks such as Reclaim The Night or Slutwalk. These demonstrations often have a carnivalesque atmosphere as women and allies gather to challenge oppression, assert their right to walk and take up space. It can also be seen in women-led groups such as Black Girl Hike and The Wonderlust Women for Muslim women.

I’ve been working with, and learning from, women who have transformed walking into powerful works of art and community building. For instance, Clare Qualmann’s East End Jam includes foraging walks around her neighbourhood and communal cooking sessions. Elspeth “Billie” Penfold combines walking and weaving, honouring her Bolivian and Argentinian heritage.

These artists, like the LRM, create communal walks. It is the being together, the moving together, that makes these wanders so special.

Conviviality is at the heart of the LRM. A convivial walk means we are navigating shared space despite, and because of, our differences. It does not homogenise but values multiplicity.

The LRM manifesto also states “the streets belong to everyone” and although we recognise this is an aspiration, not reality, it is an idea we fully commit to. Being together on a walk demonstrates how shared space can be used peacefully and creatively.


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The Conversation

Morag Rose founded and facilitates the psychogeographical collective The LRM (Loiterers Resistance Movement) a not-for-profit / mutual aid collective.

The research informing this article has been funded by the following organisations:

University of Sheffield Department of Urban Studies and Planning ERSC Funded White Rose Studentship (2014-2017)
Women Walking Manchester: Desire Lines Through The Original Modern City

AHRC Covid-19 Rapid Response Fund AH/V01515X/1 (2021-2022)
Walking Publics / Walking Arts walking, wellbeing and community during COVID-19 P.I. Prof Dee Heddon, University of Glasgow

British Academy/ Leverhulme Small Grants SG2122210842 (2021-22)
Disbelief and Disregard: Gendered Experiences of Energy Limiting Chronic Illness in England P.I Prof Bethan Evans University of Liverpool

AHRC AH/x012263/1 (2023-24)
Imagining Better Futures of Health and Social Care with and for People with Energy Limiting Chronic Illnesses P.I. Prof Bethan Evans

ref. Loitering without intent: how taking aimless walks can create community and help you feel part of a city – https://theconversation.com/loitering-without-intent-how-taking-aimless-walks-can-create-community-and-help-you-feel-part-of-a-city-273844

Aliments : le changement climatique modifie la biodisponibilité des (micro)nutriments

Source: The Conversation – France in French (3) – By Emmanuelle Reboul, Directrice de recherche, Inrae; Inserm; Aix-Marseille Université (AMU)

Les transformations profondes dues au changement climatique en cours affectent directement les systèmes de production alimentaire. Outre les problèmes de rendement, la biodisponibilité des nutriments présents dans les aliments est également modifiée, ce qui pourrait avoir des conséquences sur la nutrition humaine.


Parmi les impacts les plus marquants du changement climatique figurent la diminution des rendements agricoles due à des événements climatiques extrêmes tels que les sécheresses, les inondations ou l’exposition à l’ozone troposphérique.

De ce fait, l’accès aux aliments de base (blé, maïs, riz) pourrait devenir plus difficile, particulièrement pour les populations les plus vulnérables d’un point de vue socio-économique.

Favorisée par des températures plus élevées, la prolifération de bactéries et de champignons, qui accroît les risques de maladies d’origine alimentaire, pourrait encore aggraver cette situation.

Mais ce n’est pas tout, car au-delà de ces questions de sécurité alimentaire se pose un autre problème, moins visible : celui de la biodisponibilité des nutriments présents dans les aliments. Ce paramètre, qui désigne la fraction d’un composé alimentaire absorbée par l’organisme et acheminée vers les tissus après digestion, est également perturbé par ces bouleversements.

Pour la première fois, nous avons analysé les liens, à la fois directs et indirects, entre le changement climatique et la biodisponibilité de composés alimentaires clés : protéines, micronutriments liposolubles, minéraux, composés phénoliques et glucosinolates. Voici ce que nous a appris l’analyse de la littérature.

Le changement climatique menace les approvisionnements en protéines

Le changement climatique remet en question les sources traditionnelles de protéines animales (viande rouge notamment, dont il faudrait réduire la consommation pour améliorer la durabilité de notre alimentation, mais aussi certaines sources de protéines végétales (blé, maïs, riz) au profit de sources plus résilientes au changement climatique (millet, sorgho).

Cependant, il faut souligner que la qualité, la digestibilité et la biodisponibilité des protéines végétales peuvent être inférieures à celles des protéines animales. Ceci s’explique notamment par un manque en certains acides aminés essentiels comme la lysine, ou la présence de composés dits « antinutritionnels » tels que les phytates ou les tannins, qui interfèrent avec les enzymes durant la digestion.

En outre, l’augmentation des concentrations de CO₂ pourrait réduire la teneur en protéines des végétaux, jusqu’à 15 % pour le blé, le riz et l’orge, en faveur d’une production accrue de glucides. En revanche, les pics de chaleurs pourraient augmenter la teneur en protéines.

Micronutriments liposolubles : une vulnérabilité accrue

Les micronutriments liposolubles, comme les vitamines A, D, E, K, sont des molécules indispensables pour se maintenir en bonne santé. Or, les sources naturelles de nutriments vont probablement subir dans les années à venir les effets du changement climatique. Ce dernier menace notamment déjà certaines populations de poissons gras riches en vitamine D.

Dans le même temps, la vitamine D présente dans la viande, le lait ou les œufs pourrait être amenée à augmenter selon les régions, car sa teneur dépend de l’exposition des animaux au soleil.

Autre exemple : le changement climatique pourrait induire une baisse drastique des populations de pollinisateurs, ce qui impacterait directement la production de fruits et légumes riches en caroténoïdes provitaminiques A. Actuellement, environ 70 % de la vitamine A des aliments vient de cultures dépendantes de l’action de pollinisateurs.

Bien que l’exposition aux UV stimule la synthèse de caroténoïdes dans certaines plantes, leur teneur diminue sous des taux élevés de CO₂. Sécheresse et chaleur augmentent également les teneurs en phytates et en fibres, qui réduisent la biodisponibilité des micronutriments liposolubles en interférant avec le fonctionnement des enzymes digestives ou en ralentissant la digestion.

Les insectes comestibles pourraient offrir une solution innovante pour recycler ces composés dans la chaîne alimentaire.

Les minéraux : une disponibilité en déclin

Les carences en minéraux essentiels, tels que le fer, le zinc et le calcium, devraient s’aggraver d’ici 2050, avec une réduction estimée de 14 à 20 % de leur disponibilité globale.

Les cultures céréalières, les légumineuses, les poissons et les fruits de mer, sources majeures de minéraux, sont particulièrement vulnérables aux stress climatiques. Sous l’effet d’un CO₂ élevé, les teneurs en fer, zinc, calcium et magnésium diminuent, pouvant atteindre jusqu’à 30 % pour le fer dans les légumes-feuilles.

Cependant, l’association du CO₂ et de températures plus chaudes peut atténuer cette baisse pour certains minéraux, comme le zinc dans le blé. Comme pour les micronutriments liposolubles, la biodisponibilité des minéraux est directement affectée par la présence de phytates et de fibres.

Les composés phénoliques et glucosinolates : des réponses contrastées

Les polyphénols, abondants dans les fruits, légumes, céréales et légumineuses, jouent un rôle clé dans la prévention des maladies chroniques grâce à leurs propriétés antioxydantes et anti-inflammatoires.

Les glucosinolates, présents dans les crucifères comme le brocoli et le chou, sont quant à eux reconnus pour leurs effets anticancéreux.

Les réponses des plantes aux stress climatiques sont variables : sécheresse et chaleur peuvent soit augmenter, soit réduire les teneurs en polyphénols et en glucosinolates, selon les espèces. Leur biodisponibilité dépend également de la présence de composés antinutritionnels et de fibres.

Pour atténuer les impacts délétères du changement climatique sur la biodisponibilité des (micro)nutriments et des bioactifs d’intérêt, plusieurs pistes sont envisagées.

Enrichir et préserver les micronutriments

L’enrichissement des cultures en micronutriments, par le biais de la biofortification constitue une stratégie clé pour lutter contre les carences nutritionnelles.

Par ailleurs, l’optimisation des procédés de transformation alimentaire (haute pressionLe traitement à haute pression est une technique non thermique de conservation des aliments qui tue les micro-organismes susceptibles de provoquer des maladies ou d’altérer les aliments.
Basé sur l’application d’une pression très élevée pendant un certain temps, il a des effets minimes sur le goût, la texture, l’aspect ou la valeur nutritive.
, champs électriques pulsésL’emploi de champs électriques pulsés de haute intensité est un processus non thermique utilisé pour traiter différents types de nourriture.
Il est utilisé depuis des décennies, notamment pour pasteuriser des aliments liquides (jus de fruits, lait, œufs liquides, smoothies); extraire du jus, de l’eau et des composés bioactifs des plantes; déshydrater des tissus.
, microfluidisationApparue dans les années 80, la microfluidisation est une technique qui permet la formation de microémulsions, améliorant notamment la stabilité d’un produit.) permet de préserver la biodisponibilité des nutriments, notamment en éliminant les composés antinutritionnels, tout ayant un impact environnemental réduit par rapport aux procédés traditionnels.

Enfin, des méthodes traditionnelles comme la germination et la fermentation permettent aussi de maintenir la biodisponibilité des nutriments (comme dans le cas du quinoa).

Diversifier les sources

Il est essentiel non seulement de promouvoir des cultures résilientes, mais aussi de développer des sources de protéines alternatives.

En ce qui concerne les protéines d’origine végétale, les scientifiques travaillent à identifier des céréales qui sont non seulement résistantes aux stress climatiques, mais qui présentent également des profils nutritionnels intéressants.
C’est par exemple le cas du millet et du sorgho, cultivés en Afrique et en Asie, ainsi que des légumineuses comme les pois chiches.

Soulignons que la complémentarité entre les protéines de céréales et de légumineuses, dans un ratio de 2 :1, reste essentielle pour équilibrer les apports en acides aminés essentiels et optimiser la qualité protéique des régimes végétaux. L’emploi des protéines de pomme de terre est également envisagé.

Ces céréales pourraient remplacer les céréales actuelles dans leurs principaux usages (farines pour le pain, les pâtes, etc.), et pour circonvenir les problèmes techniques ou d’acceptation par les consommateurs, il pourrait être envisageable de ne remplacer que partiellement la céréale utilisée traditionnellement, ou d’adapter les recettes.

Par ailleurs, les protéines alternatives, comme celles issues d’insectes, de microalgues (spiruline, chlorella) ou d’organismes unicellulaires (levures), suscitent un intérêt croissant. Elles offrent un double avantage : elles présentent des profils nutritionnels favorables et leur empreinte écologique est faible.

En définitive, seule une approche globale, combinant innovation agricole, transformation durable et politiques publiques adaptées, permettra d’adapter les systèmes alimentaires aux défis posés par le changement climatique.

The Conversation

Emmanuelle Reboul ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’a déclaré aucune autre affiliation que son organisme de recherche.

ref. Aliments : le changement climatique modifie la biodisponibilité des (micro)nutriments – https://theconversation.com/aliments-le-changement-climatique-modifie-la-biodisponibilite-des-micro-nutriments-273991