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DW
7 hours ago
- Health
- DW
Sunscreens and staying safe in summer – DW – 07/25/2025
Summer and sunscreen go together. But how exactly do these products protect against skin damage and lower your cancer risk? Skin cancers, of which more than 300,000 new cases are diagnosed each year, are preventable. And yet cases continue to rise, particularly in regions of the world where numbers have previously been low. As well as avoiding direct sunlight and wearing protective clothing such as hats, long-sleeved shirts and pants, effective sunscreen products have been available for years. But as genuine concerns about product safety mix with myths and falsehoods on social media and elsewhere online, some people may move away from these cancer-preventing products. "The most important thing that I always want to emphasize in any of the research I'm doing is the importance of using [sunscreen]," said Richard Blackburn, a materials scientist at the University of Leeds and Keracol Limited, UK, who researches and develops new sunscreens and skin products. "We should be worried about skin, skin damage, DNA damage, skin aging, so the use of a sunscreen, if you're going to be out, is really, really important." Ultraviolet (UV) light is emitted by the sun, penetrates Earth's atmosphere and reaches the surface. And it's dangerous. "UV damages all living things," said Antony Young, a photobiologist at Kings College London, UK. UV is invisible but the damage it causes to humans when it's absorbed by the skin is obvious. Even a short-term exposure to sunlight — sometimes less than half an hour — can cause sunburn. There are two types of UV light: UVA and UVB. UVA is a longer wavelength form of ultraviolet and reaches deep layers of the skin. UVB usually penetrates the outer skin layers, such as the epidermis, and is the main cause of sunburn. Even people with darker skin tones need to be careful of UV. While natural pigmentation can provide a temporary guard against ultraviolet light, skin is skin, and damage can still occur after extensive exposure. In the 20th century, sunscreens were developed to reduce the harm caused by UV. They contain many ingredients but are generally divided into two categories based on their active properties. One of these are "chemical" sunscreens. But scientists are trying to move away from that description because, after all, everything on our planet is made of chemicals. The term they prefer is "organic sunscreen" because they contain carbon-based active ingredients. These molecules absorb and diminish UV rays when they hit the skin, helping to prevent sunburn. The other category is sometimes called "physical" or "natural" sunscreens. The active ingredients in these are chemicals too — but they aren't carbon-based. Instead, these use titanium or zinc oxide particles to provide a physical filter. Both sunscreens absorb and block UV from penetrating and damaging skin. The radiation is released as heat. While no sunscreen filters out 100% of UV, they are vital at blocking out an overwhelming amount of it. Suncreens are rated using protective factor labels, abbreviated to "SPF' or "UPF,' indicating how much UV is filtered out. SPF15, for example, filters away 93% of UVB radiation; SPF30 filters 97%, and SPF50 filters 98%. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Health authorities are increasingly vocal about the importance of using sunscreen, and general sun protection, to prevent skin damage and reduce skin cancer rates. But these messages are also competing with claims, including ones circulated on social media, that sunscreen can do more harm than good. Some of these are falsehoods misrepresenting data. Bu there are also reasonable concerns about the safety profile of some chemicals that have been used in sunscreen for years. While these have generally been considered safe, some long-approved substances like oxybenzone, avobenzone and octinoxate have been detected in the bloodstream, and may break down into toxic compounds. The question scientists — and health regulators — are asking is, are these toxins enough to pose a danger? "What matters is the dose," Young said. "This is also true with concerns about sunscreen pollution into the oceans. The trouble is a lot of the toxicity studies are done with doses that are not going to be achieved, or [are] very difficult to achieve." Among other recommendations from dermatologists and researchers are for consumers to pay attention to expiry dates, storage conditions and to avoid mixing different sunscreens at the same time. That includes cosmetics that have an SPF rating. Blackburn's research has shown applying two different types of sunscreen products can diminish their protective benefits. "We found it actually can reverse the whole process by combining those [different sunscreens] together, and that's very counterintuitive," Blackburn said "You would almost think you're layering and layering and you get better [protection], It's not the case." But the SPF of these ingredients is usually negligible. Products marketed as "natural" will usually contain chemicals like zinc or titanium oxide to provide adequate protection. Young warns against do-it-yourself sunscreens. "The thing about these homemade efforts is that you can't test them. Formulating a sunscreen is quite a technically tricky job to get it both cosmetically appealing, stable and also protective." To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video While most sunscreen chemicals, whether skin-aborbed carbon compounds or physical protectors like zinc are the current gold-standard for SPF, scientists are finding new chemicals in nature. Like many pharmaceuticals, chemical compounds evolved by plants, fungi and other animals could be harnessed to provide health benefits. "There are natural chemicals that have the potential to be protective," said Young, "And plants in particular produce chemicals to protect their DNA." Labs like those run by Blackburn are trying to identify, isolate and produce such chemical compounds for use in sunscreens. It could reduce the reliance on lab synthezised chemicals in future sunscreens, though in places like the US, these would still need regulatory approval. "Everything is chemistry," Blackburn said. "If we can understand from a chemical level and a mechanistic perspective what's working, we can actually improve [sunscreen], look to... plants that can provide the same function."
Telegraph
2 days ago
- Health
- Telegraph
Revealed: The number of steps you need to improve your life expectancy
Walking 7,000 steps a day is the sweet spot for preventing many chronic diseases that can lead to an early death, a major study has shown. While the goal of 10,000 daily steps has become firmly established in the public consciousness, an international team of researchers found even a modest amount of walking brings major benefits. British scientists said it finally 'debunked the myth' of 10,000 steps and should encourage people to try and hit the lower target. The major review of 57 studies involving 160,000 adults, which was published in The Lancet, concluded that for most conditions health benefits tended to level off beyond 7,000 steps. Hitting 7,000 steps a day was found to reduce all-cause-mortality by 47 per cent, cardiovascular disease by 25 per cent, cancer by six per cent, diabetes by 14 per cent, dementia by 38 per cent and depression by 22 per cent. Health benefits were also apparent from 4,000 steps when compared to 'inactive' people who walked just 2,000, the study led by the University of Sydney found. Every extra 1,000 steps brought better outcomes, researchers found. Commenting on the study, Steven Harridge, professor of human and applied physiology at King's College London, said: 'Humans are designed to be physically active – our evolutionary heritage as hunter gatherers. 'There has been debate about the amount of activity an individual should be doing with 10,000 steps as a generalised target, not well evidenced. 'This paper shows that 7,000 steps is sufficient for reducing the risk for most diseases covered, and 10, 000 steps does not confer much additional benefit.' According to World Health Organisation data, insufficient physical activity is the fourth most frequent cause of death in the world, with 3.2 million deaths a year related to physical inactivity. Many health organisations recommend hitting 10,000 steps a day, although there is little evidence for the target, which is believed to have arisen from a Japanese marketing campaign in the 1960s. In the run-up to the 1964 Tokyo Olympics, the company Yamasa sought to capitalise on the sudden interest in fitness, so designed the world's first wearable step-counter. They called it the Manpo-kei, or '10,000-step meter'. The company appears to have chosen the figure at random, as a fun goal, but it has stuck ever since. The new paper found that for heart disease, walking more than 7,000 steps was beneficial, but for most conditions there was little gain from putting in more effort. Experts said it was still unclear why walking brings such striking benefits but said it is likely to increase cardiorespiratory fitness, which is known to be positively associated with better health and all-cause mortality outcomes. Commenting on the research, Dr Daniel Bailey, an expert in sedentary behaviour and health at Brunel University of London, said the 7,000 steps target was more achievable for many people than 10,000 steps. 'Just adding more steps from your starting point can have important benefits for health,' he said. 'This study adds to existing evidence by showing that the more steps people do, the less their risk of developing different health conditions. 'The finding that doing 5,000-7,000 steps per day is beneficial, is an important addition to the literature which helps to debunk the myth that 10,000 steps per day should be the target for optimal health.' The Alzheimer's Society also welcomed the study saying it demonstrated that inactivity is a major risk factor for dementia. Dr Richard Oakley, associate director of research and innovation at the charity said: 'It adds to the evidence that what's good for the heart is good for the head.'
Medscape
2 days ago
- Health
- Medscape
Could Ketamine Addiction Become the UK's Next Drug Crisis?
Doctors are warning that ketamine is not the harmless party drug many believe it to be, as rising numbers of young people in the UK are being treated for addiction and serious organ damage. Despite the surge in use, many users — and even frontline clinicians — remain unaware of the drug's addictive potential and its severe physical health consequences, including bladder failure, kidney damage, and extreme weight loss. According to the Home Office, an estimated 299,000 people aged 16-59 had reported ketamine use in the year ending March 2023 – the largest number on record. In a June 2025 editorial in The BMJ , addiction psychiatrists said that 3609 people began treatment for ketamine addiction in 2023-2024. That is more than eight times the number recorded in 2014-2015. The drug's relatively low cost made it popular among young people, according to the experts from King's College London and South London and Maudsley NHS Foundation Trust. 'Not Just a Party Drug' Dr Irene Guerrini Consultant addiction psychiatrist Dr Irene Guerrini, who led the study, told Medscape News UK : 'The vast majority of clinicians think ketamine is a party drug used at clubs and raves, but it's not just that. My young patients often go to A&E and primary care and are told ketamine is not addictive, but it is addictive and can cause serious harm.' Guerrini said that ketamine uropathy is the most common complication of frequent use. 'It causes serious bladder, kidney and liver problems, and often extreme weight loss, which can be confused with an eating disorder by some health professionals.' Earlier this month, Alder Hey children's hospital in Liverpool opened a specialist ketamine clinic to treat young people under 16 for ketamine-induced uropathy. Physical and Psychological Harm A separate study by the University of Exeter and University College London (UCL), published in the journal Addiction in April, also found a strong link between ketamine addiction and physical and psychological health problems. Among 274 people with ketamine use disorder, 60% had experienced bladder or nasal problems. More than half (56%) reported painful cramping in the abdomen, known as 'k-cramps'. Chemicals released when ketamine breaks down in the body can damage the bladder lining, leading to pain, bleeding, and scarring. Some bladder damage was so severe that it required bladder removal and the use of a urostomy bag. Celia Morgan Study author Professor Celia Morgan, of the University of Exeter told Medscape News UK , ' Ketamine use is increasing. We have observed users are younger and the trajectory to dependence seems fast in some individuals. 'In those who are sucked in to repeated heavy ketamine use, the physical consequences are severe in terms of bladder complications, but also dramatic weight loss and in severe cases, multi-organ failure.' Sharp Rise in Rehab Admissions UK Addiction Treatment (UKAT) centres have reported a surge in people seeking help. Zaheen Ahmed Zaheen Ahmed, director of addiction treatment at UKAT, told Medscape News UK that there had been ' a staggering rise in both enquiries for help and admissions into our centres'. Admissions were up 35% in 2024 compared with the previous year. 'Ketamine addiction has become the norm, and we're seeing it and treating it daily now,' he said. Ahmed warned, 'Ketamine is a really dangerous drug, because it doesn't give the user an awful come down like other substances do.' The drug is also 'incredibly cheap, making it very appealing, especially to young people'. Medical Use and Misuse Ketamine is used clinically as an anaesthetic. At lower doses, it is prescribed for chronic pain, treatment-resistant depression, and suicidality. It is also being trialled in studies to treat post-traumatic stress disorder (PTSD) and severe alcohol dependence. However, experts have warned that increasing availability through private clinics may normalise unsupervised or self-directed use. The drug has also been linked to the deaths of Friends actor Matthew Perry and drag performer The Vivienne. Missed Diagnoses in Primary Care The Exeter/UCL Study found that most people with ketamine use disorder do not seek treatment. Existing services are often perceived as ineffective. 'In our study, a common report was that doctors and health professionals were ignorant to ketamine addiction and its physical health impacts,' said Morgan. 'We need to urgently raise awareness and educate professionals of this often devastating and life-threatening condition.' Guerrini agreed that doctors should be more alert to the possibility of ketamine addition. 'M aybe if I'm a GP and see a particularly young patient coming to me with a urinary tract problem like cystitis, be I'll be more inquisitive, ask the correct questions, and think maybe this patient is on ketamine.' Similarly, A&E doctors should develop 'clinical curiosity' if a young patient has high liver enzymes and severe pain. Guerrini called for better diagnostic tools, a national registry, and earlier screening to support treatment and help evaluate emerging therapies. 'It's important to increase awareness among professionals and encourage joined up working between substance misuse services, urology services, and mental health services, as these young people often have chronic depression along with physical issues caused by ketamine,' she said. Government Considering Reclassification Ketamine is currently controlled as a Class B substance. The maximum penalty for supplying and producing it is up to 14 years in prison, an unlimited fine, or both. Earlier this year, the Home Office asked independent experts for advice on whether ketamine should remain controlled as a Class B substance or become a Class A drug. Ahmed said that reclassification would increase penalties for dealers, but more importantly, ' it will hopefully discourage young people especially to even experiment with it at all'.
Yahoo
2 days ago
- Health
- Yahoo
The three types of hunger – and how to stay fuller for longer
For some people, eating a meal keeps them happily satiated until the next one, whereas for others, hunger is a far more complicated business. A couple of hours after eating, they're starving again and trying desperately not to succumb to the lure of the fridge or office vending machine. But is what they're experiencing really physical hunger, also known as homeostatic hunger, or could it be fuelled by one of the other kinds? There is hedonic hunger – the drive to eat for pleasure, rather than out of a physiological need for energy and, one of the most persuasive, emotional hunger, where food serves as a form of self-soothing when negative feelings arise. 'Physical hunger, when your body needs refuelling, is just one type of hunger, but we don't necessarily talk about the other types as much – although we should, because understanding them can be important for our health,' says Dr Emily Leeming, a microbiome scientist at King's College London, dietician and author of Genius Gut. Hedonic and emotional hunger are among the main culprits when it comes to weight gain. In fact, a broad new review of existing research found a significant positive link between hedonic hunger and food addiction, defined as symptoms similar to those in drug addiction, including cravings, tolerance and withdrawal effects – as well as to increased calorie intake and weight gain. So which might you suffer from? Here's a science-backed guide to all three, understanding their triggers and learning how to beat them. Physical hunger That empty-stomach feeling, often accompanied by a growling sound, dip in energy and 'hanger' (hungry anger) – caused by cortisol and adrenaline rising as our blood sugars drop – is our body's way of signalling to the brain that we need food. This drop in blood sugar and insulin levels, a few hours after eating, triggers the stomach to produce ghrelin, the hormone that stimulates appetite. But for some of us, our appetites seem to be in overdrive. The reasons for this can be complex: some people seem to be less sensitive to the suppression of ghrelin that comes when the stomach encounters food, while for others, their brains could be less sensitive to leptin signals, which tell the brain to stop eating when we're full. For most people, however, focusing on what we eat can make a huge difference in managing our hunger. Eating too many refined white carbohydrates is one of the primary reasons many of us find ourselves reaching for sugary snacks between meals. 'With white or refined carbs, such as white bread, pasta and rice, most of their nutrients and fibre have been lost, so our bodies don't have to work hard to break them down,' says Laura Southern, the founder of London Food Therapy. 'That causes very high blood sugar spikes.' These trigger an immediate release of insulin, causing blood glucose levels of fall, which then signals the release of hunger hormones to replenish them. Research from King's College London has shown that when blood sugar levels dipped below their baseline, people reported a 9 per cent increase in hunger and ate over 300 calories more that day than others whose blood sugar levels did not dip. Tips to stop physical hunger pangs Opting for unrefined carbs, such as oats, barley, rye and quinoa, will help keep blood sugar steady thanks to their higher fibre content. 'Ninety-three per cent of us are not getting the fibre we need, and we have a deficit of 35 to 40 per cent, which is a significant fibre gap,' says Dr Leeming. 'Fibre releases fullness hormones and it's quite bulky, so it gives that sense of fullness and satisfaction. It also feeds our gut microbiome, and there's early evidence that looking after the microbiome could potentially be involved in how tempting we find certain foods.' She recommends starting the day with a protein-rich breakfast, such as yogurt or eggs, which has been proven to reduce food cravings and snacking later in the day, and adding fibre, such as fruit, vegetables or seeds. Hedonic, or taste-hunger pangs It's the smell of the freshly baked croissants we cannot resist on holiday; or that irresistible extra portion of the darkest, ooziest chocolate fondant cake for pudding, followed by the cheese board. Eating for pleasure is one of our biggest drivers to consume more than we need. Food, quite rightly, is a sensory joy – and we all experience a hankering for the fattier, sugary treats, with temptation and advertising bombarding us from all corners. But for some, these cravings can spiral into persistent 'food noise' – intrusive thoughts about eating – or even develop into full-blown addiction. 'When we eat foods we find particularly appealing, our brain releases dopamine in its reward system,' explains Dr Anne-Laure Le Cunff, a neuroscientist at King's College London and founder of Ness Labs. 'This creates a sense of pleasure and reinforces the behaviour.' Unlike homeostatic hunger, which we often mistake it for, hedonic hunger, aptly named after Hedone, the Greek goddess of pleasure, has no mechanism to signal when we should stop eating – hence, it's now seen by scientists as one of the biggest causes of obesity. Tips to stop hedonic hunger pangs But there are measures we can take to combat these cravings, and they aren't as simple as trying to avoid food for which we have a weakness. Dr Leeming says: 'Cutting out the food we crave won't necessarily solve the craving: one study showed that women who cut out chocolate had more food cravings, and when they did eat chocolate, they ate twice as much.'Instead, she suggests eating the food, but with something else. 'If it's chocolate, have it with some fruit and nuts, which combine protein, fibre and healthy fat, so you'll probably eat less chocolate and it's going to satisfy you more,' she says. Dark chocolate is a better choice, with research suggesting it could have a positive impact on blood sugar levels, reducing cravings for less nutritious foods later. Maintaining a consistent eating pattern, including meal-times and portion sizes, is key to managing cravings, as a result of what's called the cold-hot empathy gap. In the cold state (meaning you're not starving hungry, and therefore feeling neutral, or 'cold' towards food) you're less likely to overestimate how hungry you'll be and overindulge – so this is the state to be in when you're planning meals. Getting enough sleep is also vital: research shows that just one night of poor sleep can significantly boost your ghrelin levels, making you snack more the next day. Eating spicy foods can help beat cravings, too. Capsaicin, the compound that makes peppers spicy, can suppress appetite and increase satiety. And don't skip bitter vegetables, such as dark leafy greens, since studies have shown they can trigger the release of appetite-control hormones in the gut and reduce our desire for sweet foods. Emotional hunger Research published last year by scientists at the University of California, Los Angeles in America found that women who perceive themselves to be lonely showed more brain activity in areas associated with food cravings, especially when shown pictures of high-calorie or sugary foods. The dopamine hit we experience when we eat these foods 'essentially teaches our brain that eating makes us feel better,' says Dr Le Cunff. For many people, this link between food and comfort is strong and dates way back to our childhoods. 'Over time, our brains learn to link eating with emotional relief,' says Dr Le Cunff. So when we're struggling emotionally, we're hard-wired to seek this kind of comfort, she explains. 'When we're stressed or feeling low, our brain's emotion centre, the amygdala, becomes more active and interacts with areas that control both hunger and reward-seeking behaviour.'Unfortunately, this can create unhealthy patterns, seeing us reach for food as comfort every time we experience negative emotions, then feeling guilty and ashamed – which can lead to yet more bingeing. Recognising that emotional eating is a normal part of life is important, Dr Leeming advises: 'Don't beat yourself up – think about the bigger picture of what you're eating in a week.' How to stop emotional hunger pangs Taking note of the feelings which lead to unhealthy eating can help identify your triggers, which is the first step in breaking the pattern. Next time you experience one, Dr Le Cunff says: 'Many other activities can activate similar reward pathways, in healthier ways, and these alternatives can help us regulate our emotions without relying on food.'Try contacting a friend – even a text message can provide the social connection that increases bonding hormones such as oxytocin. Or go for a walk or dance around the kitchen to uplifting music. As little as 10 minutes in Zone Two, where your heart rate is around 125-140 BPM and you can talk but not hold a proper conversation, can increase dopamine levels. Yoga, meditation and deep breathing can help us cope with stress, as can creative pursuits such as painting, writing, or gardening – and they can all act as a diversionary tactic to take our mind off the craving until it passes. Broaden your horizons with award-winning British journalism. Try The Telegraph free for 1 month with unlimited access to our award-winning website, exclusive app, money-saving offers and more.
Al Jazeera
16-07-2025
- Politics
- Al Jazeera
Ceasefire agreement 'harder' to reach as Israel strikes Syria
Ceasefire agreement 'harder' to reach as Israel strikes Syria Quotable 'I don't think that Israel and Syria are going to reach an agreement any time soon.' Robert Geist Pinfold, a lecturer at King's College London, explains why the Israeli attacks on Syria's capital Damascus will make it harder to reach a ceasefire agreement between the two countries. Video Duration 01 minutes 05 seconds 01:05 Video Duration 01 minutes 14 seconds 01:14 Video Duration 01 minutes 37 seconds 01:37 Video Duration 01 minutes 10 seconds 01:10 Video Duration 01 minutes 02 seconds 01:02 Video Duration 01 minutes 00 seconds 01:00 Video Duration 01 minutes 47 seconds 01:47
