DNA ‘barcodes' shed light on how the blood ages
It could also pave the way for the exploration of therapies that slow down or reverse ageing, researchers suggested.
The study, published in the journal Nature, identified stem cells that gradually take over blood production between the ages of 50 and 60.
These cells, known as 'clones', prefer to produce myeloid cells, a type of immune cell linked to chronic inflammation.
Young people have between 50,000 and 200,000 stem cells, which are responsible for replacing between 100 billion and 200 billion blood cells every day.
'As we age, some of these stem cells disappear and their function needs to be taken over by others, which then expand,' said Dr Lars Velten, group leader at the Centre for Genomic Regulation (CRG) in Barcelona.
'And by the age of 50 or 60, we get these clones. This is a group of cells that stem from the same mother stem cell.
'And these clones are important because they are first step in leukaemia formation, and they also contribute to inflammation, because the blood cells that derive from them are emitting molecules that fuel the inflammation process, and therefore there's also this link to heart disease risk.'
According to Dr Velten, tracking every blood cell back to its original stem cell has been possible only in animal research.
His team looked at changes in the chemical tags, known as methylation marks, attached to DNA.
Theses tags help cells know which genes to switch on and off, and when a stem cell divides, methylation marks are copied to its daughter cells.
'This is sort of like having a unique barcode for every cell when we're young, and then this barcode identifies all the descendants, all the children and grandchildren and great-grandchildren, of these cells as we age,' Dr Velten added.
To read these 'barcodes', scientists developed a technique known as EPI-Clone.
They used it to reconstruct the history of blood production in both mice and humans, tracing which stem cells contributed to making blood.
In older mice, EPI-Clone showed that blood stem cells comprised just a few dozen large clones.
The pattern was also found in humans, with larger clones taking over blood production from age 50.
This discovery could one day allow doctors to look at how a patient's blood is ageing, potentially years before diseases develop, researchers suggested.
Dr Alejo Rodriguez-Fraticelli, also group leader at IRB Barcelona, said: 'The idea is that this could be an early intervention tool for cancers, starting with blood cancers, where we know that expansions in these stem cells identify individuals that are at risk of developing blood malignancies.'
The study also found many of the dominant clones produced myeloid cells, which are linked to chronic inflammation.
Research using mice has shown removing these particular clones can rejuvenate blood stem cells.
Researchers are hopeful the tool could pave the way for the exploration of rejuvenation therapies in humans as it allows for scientists to pinpoint problematic clones.
Dr Rodriguez-Fraticelli added: 'If we target the expanded clones, there may be the hope that we may ablate them and then let the diversity of the hematopoietic system, the blood regeneration system, really rejuvenate.'
Dr Velten said: 'If we want to move beyond generic anti-ageing treatments and into real precision medicine for ageing, this is exactly the kind of tool we need.
'We can't fix what we can't see and for the first time, EPI-Clone can facilitate this for humans.'
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The Guardian
12 hours ago
- The Guardian
Helm by Sarah Hall review – a mighty epic of climate change in slow motion
Even if Sarah Hall did not begin her acknowledgments by saying that it's taken her 20 years to write Helm it would be evident. Not from a cursory glance at her bibliography, perhaps: in that time Hall has published six other novels and three volumes of extraordinary short stories. But in every other way, and the moment you begin reading. There's the subject, for starters. Ever since the first paragraph of her first novel, Haweswater, in which an early 20th-century man drives his horse and cart through the waters of a Cumbrian valley recently drowned by a dam, Hall has been concerned with landscape, with weather, with nature in all its forms, with the ways in which we affect each other. In The Carhullan Army, climate change has already happened. Cumbria is semi-tropical, temperate England a folk memory; a dystopian vision that feels, this baked summer, uncomfortably close to reality. 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An ice age, sun flares, ash cloud; and, relatively insignificant in the context of such deep time, the evolution of humanity. Because there are many people in the novel, too, which is structured by braiding their stories with Helm's, but also with lists: the forces of Helm, for instance, which range from '0. Zero Helm (complete calm). Mean wind speed < 1mph. Weathervanes and trees unmoving, grass still, water as mirror, smoke rising vertically from roundhouses/cottages/plague pyres' to '12. Hurricane Helm (Hand of God). Wind speed 73-83mph, phenomenal damage and widescale loss of life, Eden reconfigured biblically, Carlisle-Settle train lifted off the tracks, history made, FIN.' Other lists include names for Helm and the damage Helm can wreak; or the trinkets Helm collects, often after that damage (Howdah pistol, iron skullcap, Apple iPhone 11 64GB, Tornado F3 series, eject pin). The pictures humans make, trying to understand, locate, corral Helm. Helm finds people amusing, and watches as they succeed each other; Hall's ambition may be bounded by one valley, but it reaches through thousands of years. Her subjects range from a neolithic tribe to a medieval exorcist; from an isolated 18th-century wife to a quixotic Victorian meteorologist; from a wind-touched, lonely mid-20th-century child to a present-day academic counting plastic particles in the air. From stone tools to the Industrial Revolution to the advent of AI, each era has its own existential encounters with Helm: as deity or devil, as a psychological or a scientific mystery. Both sides are made complacent by Helm's longevity, size and power, by human smallness and briefness, neither realising, until perhaps too late, that these little beings threaten Helm's own existence. A project of this scope, which requires a range of research and imagination that could have produced several historical novels, not to mention an entire other volume of meteorological expertise, holds so much in suspension around its whirling, windy core that it could easily blow apart. But, despite the occasional threat or lull, Helm doesn't. Partly, I would argue, this is because of Hall's development as a consummate short story writer. Her novels are never less than hugely accomplished, but the narrative demands of the longer form, especially in more conventional earlier work, can sometimes dissipate the blaze of which she is capable. Hall is freed by the constraints of the short story – like the female sculptor in her last novel, Burntcoat, she burns away everything extraneous – and her work only gains in concentrated, suggestive power. Each strand of Helm has this concentration; the characters and voices could stand alone, but they flow together into something deep and rich, held together by the Eden valley, and its Helm. And by the writing. Hall's work on place, and especially this corner of England, has always been virtuosic, a tough and supple poetry anchored in decades of attention to Cumbrian land and plants and skies. In her first novels it sometimes threatened to submerge everything else, but in Helm is so embedded on the page that it's easy to take for granted, until you pause and back up to really look at the 'dirty, clay-slipped sky', or a gaggle of Victorian children, born into the shantytown that grows up around the railway, collecting on a hillside to eat magic mushrooms and stare at the 'silly jinking stars'. Every era in Helm has its own seeing; the same land, the same wind filtered through time-specific fears and hopes and work, time-specific knowings, from a neolithic world interpreted through animal behaviour to the bathos of 21st-century cycling waterproofs, pub menus, emails. Hall has a thrilling command of vocabulary, with the concurrent deployment of etymologies and the hinterlands they bring; words often work not as single notes, but as chords, big ideas slipping in on the wakes of concrete specificities. So NaNay, a neolithic girl, watches as the wind approaches: 'In the centre it was blue-grey, like bull-hide, with the dull pearl-shine of scales at its edges. It was faceless and its body was its only government.' The 'spectral gap' is a technical term of modern mathematics and quantum mechanics as well as meteorology. But what heft and metaphorical possibility such a gap has, when a retired policeman in a glider is required to fly into it. Above all it is the wind itself that holds this vastly ambitious, serious – but also often playful and ironic – book together. Some might find Helm's voice initially a little arch, a little unplaced relative to the human voices, but it grows on you. Antic, needy, angry, curious, millennia-old Helm, who gives and takes, fascinates and awes, is feared and loved, and loves in return; who absorbs violences, propitiations, yearnings, and who is now beginning to feel 'a bit wrong'. There has been so much change, over so many millennia, but this is different. 'It's complicated. Hard to put Helm's fingers on it.' It isn't that Helm is old, more that 'Whatever is wrong … feels insidious, sneaky, infectious. The surprise disease on the routine tests. Some kind of weird intimate growth you find accidentally and go, Jesus, how long has that been there? A toxic waft when you're asleep. Lights out.' Sign up to Inside Saturday The only way to get a look behind the scenes of the Saturday magazine. Sign up to get the inside story from our top writers as well as all the must-read articles and columns, delivered to your inbox every weekend. after newsletter promotion The neolithic tribe listens to Helm in its prime, 'splintering and shredding the valley, its voice mourning its own violence'. In the mid-20th century Helm searches for a young girl, his friend, who has been locked in an asylum, and, trying to look beyond the valley, 'rises, higher, until being is difficult'. At the 21st-century meteorological observation post, 2,000ft up, Helm whips and churns and 'calls to awful prayer'. A prayer for itself, perhaps, because whatever Hall's intentions – an urgent rallying, a tribute, a warning – this novel reads like nothing so much as an elegy. Helm by Sarah Hall is published by Faber (£20). To support the Guardian order your copy at Delivery charges may apply.
Daily Mail
2 days ago
- Daily Mail
Mystery of ancient DNA marker rewrites story of how humans first reached the Americas
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Telegraph
2 days ago
- Telegraph
The simple food swaps that can double your weight loss
'If two diets are nutritionally equal, according to nutritional guidance, does the level of processing still affect weight and health?' It's the question Dr Sam Dicken, a research fellow in the department of behavioural science and health at University College London (UCL), set out to answer in a landmark study published in Nature. The results showed that people who ate a diet of minimally processed foods (MPFs) lost twice the weight as those eating ultra-processed foods (UPFs) – even when both diets met Government healthy-eating guidelines. In the UK, more than half our calories come from UPFs such as ready meals, breakfast cereals and mass-produced bread. These everyday foods have been linked to more than 30 chronic diseases, including obesity, type 2 diabetes and stroke. Until now, most research has centred on nutritionally poor UPFs – high in sugar, salt and saturated fat, while low in fibre. This is the first study to focus on 'healthy' UPFs that meet nutritional recommendations for fat, saturated fat, protein, carbohydrate, salt, fibre, fruit and vegetables. 'Not all UPFs are inherently unhealthy,' says Dr Dicken, the lead author of the study. 'Supermarkets now offer plenty of healthier, nutritionally balanced UPFs, like wholegrain breakfast cereals and high-fibre ready meals.' Rob Hobson, a nutritionist and the author of Unprocess Your Family Life, says the study adds to concerns about the role of UPFs in weight gain and wider health. 'It's not just about additives, calories or sugar, but how food is made and how that affects our eating behaviour,' he explains. 'Relying less on UPFs – even ones marketed as 'healthy' – can support better weight management and long-term health.' While cutting out all UPFs is unrealistic in our current food environment, making a few, smart food swaps can make all the difference, say the scientists. Here's how to do it. Swap breakfast cereal with milk for overnight oats with frozen or fresh fruit Most breakfast cereals are ultra-processed, even those labelled 'wholegrain'. While often fortified with vitamins and minerals, they are typically sweetened and low in fibre – leaving you hungry again by mid-morning. 'Switching from a sugary, ready-made cereal to homemade oats with milk and fruit reduces calorie and sugar intake while boosting fibre, protein, antioxidants, vitamins and calcium,' says Dr Adrian Brown, the study's co-author and a senior research fellow in nutrition and dietetics at UCL. ' Oats provide slow-release energy, helping control blood-glucose levels, which may keep you feeling fuller for longer. Overall, they're a better option.' A review in Current Nutrition Reports found eating oats can support weight management by reducing body fat and regulating appetite. Rob Hobson's quick-and-easy overnight oats recipe Mix 50g rolled oats with 100ml semi-skimmed milk and 100ml apple juice Add half a grated apple, 1 tbsp chia seeds, and a squeeze of lime juice. Leave overnight in the fridge Top with berries and a spoonful of natural yogurt Swap a meal-deal chicken sandwich for homemade chicken-salad flatbread Even healthy-sounding sandwich fillings, such as chicken, can be processed or loaded with saturated fat and calories, especially with added mayonnaise. ' Pre-packaged sandwiches, often made with ultra-processed bread, have a soft texture that may encourage faster eating and less awareness of fullness,' says Hobson. A study in Cell Metabolism found people on a UPF diet ate twice as fast and consumed 50 per cent more calories per minute – an extra 500 calories per day. 'A homemade flatbread with grilled chicken, salad and a yogurt-based dressing contains lean protein and fibre in a more structured meal, encouraging you to eat more slowly and feel more satisfied,' says Hobson. Rob Hobson's quick chicken flatbread recipe Fill a wholemeal flatbread with 80-100g grilled chicken breast, mixed salad leaves, sliced cucumber and tomato Add a spoonful of plain yogurt, lemon juice and fresh herbs, such as coriander or parsley Swap a spaghetti bolognese ready meal for a homemade equivalent 'A ready-made spaghetti bolognese will contain processed meat that may be higher in fat and saturated fat,' says Dr Brown. 'It will be more energy-dense, providing more calories per bite.' The soft texture doesn't require much chewing, so you will eat faster and potentially override your body's satiety signals, consuming more before you realise you are full. 'Switch to a homemade version, made with lean, 5 per cent mince, and you'll likely eat fewer calories and less saturated fat for the same portion size,' says Dr Brown. 'Improve the protein and fibre content by adding lentils, vegetables, herbs and spices, and serving with wholewheat pasta. This will help you feel fuller.' Swap low-fat fruit yogurt for low-fat natural yogurt with fruit Low-fat fruit yogurts are often highly processed, with added sugars or sweeteners, flavours and thickeners. 'The label may show moderate calories, but the texture and sweetness can make them less filling and more rewarding to the brain, encouraging you to eat more,' says Hobson. 'A natural yogurt with whole fruit or a little honey is less processed, has more texture, and provides protein and natural fats that keep you fuller for longer. You can also control the sugar content.' If you're trying to lose weight, Dr Brown advises checking labels. 'Some natural yogurts are higher in fat – look for a reduced-fat option,' he says. Swap processed nut snacks for whole nuts 'Processed nut snacks [such as a fruit-and-nut bar], especially flavoured ones, are often UPFs even if they include nutritious ingredients,' says Hobson. 'Their engineered textures and sweet-salty profiles can drive reward-driven eating.' That's why it's so hard to stop at one handful. Whole nuts with dried fruit provide more fibre, slowing down eating speed and energy release. 'This reduces calorie intake and help control appetite,' says Hobson. A Harvard study found people who ate whole nuts were less likely to gain weight gain. If processed fruit and nut bars are your go-to, Dr Brown recommends the following: 'Swap for a small, 25g handful of unsalted nuts, such as almonds or walnuts, plus a piece of fruit,' he says. 'You'll get less salt, more vitamins, minerals, antioxidants and fibre – and the fruit counts towards your five a day.' What we can learn from the UPF v MPF trial In the trial, 55 overweight adults were given either: a UPF diet of convenience foods, such as cottage pie ready meals, fortified cereals and pre-packaged sandwiches an MPF diet of homemade meals, such as cottage pie, overnight oats with berries, and chicken salad with flatbread Both diets met the UK's Eatwell Guide, which outlines the main food groups and their recommended proportions for a healthy, balanced diet. Meals were delivered for eight weeks, with no calorie counting or portion control. After a four-week break, participants switched diets, for another eight weeks. Both groups lost weight, but people eating MPF meals lost twice as much (2 per cent of body weight, versus 1 per cent on the UPF diet). 'Continued over a year, the MPF diet could mean a 9 to 13 per cent weight loss, compared with 4 to 5 per cent on the UPF diet,' says Dr Dicken. 'That's significant.' The MPF diet also led to greater fat loss, especially visceral fat, which raises the risk of metabolic disease. Neither diet caused muscle loss – likely because the diets were nutritionally balanced. 'The main message is that nutritional guidelines work – both groups lost weight,' says Dr Dicken. 'However, processing still makes a difference. Choosing foods that are less processed may help you lose more weight.' UPFs are engineered to be moreish. 'They can often be energy-dense, with more calories per bite, and softer in texture,' says Dr Dicken. 'This makes them easier to eat quickly, so you consume more before your brain realises you're full.' By contrast, MPFs are bulkier, higher in fibre and take longer to eat, so they are more filling. In the trial, MPF participants consumed about 290 fewer calories a day, compared with 120 fewer on the UPF diet. They also found it twice as easy to resist cravings. Healthy weight loss tips from the experts Dr Sam Dickens says: Follow the Eatwell Guide: more fruit, vegetables, wholegrains, pulses, nuts, lean proteins. Fewer than 0.1 per cent of Britons follow all the guidelines. Prioritise high-fibre foods. Check calorie density and be cautious with calorie-dense foods that have a soft texture, because they're easier to overeat. Using front-of-pack labelling as a guide, aim for foods with around 120-130 kcal per 100g. Dr Adrian Brown says: Speak to a GP or practice nurse. You may be eligible for structured support, such as the NHS Digital weight management programme or a local referral scheme. Avoid focusing solely on weight loss. Concentrate on improving your general health and small-scale victories, such as better sleep, improved energy, or being able to play with your grandchildren. Having other goals keeps you motivated and supports long-term success. If it feels overwhelming, reach out for support. Weight regulation is complex. No one should feel they're expected to do it alone.
