Published23 minutes agoShareclose panelShare pageCopy linkAbout sharingImage source, Getty ImagesBy James GallagherHealth and science correspondentAfter more than three billion doses, the Oxford-AstraZeneca Covid vaccine is being withdrawn.AstraZeneca said it was “incredibly proud” of the vaccine, but it had made a commercial decision.It said the rise of new coronavirus variants meant demand had shifted to the newer updated vaccines.Its vaccine was estimated to have saved millions of lives during the pandemic, but also caused rare, and sometimes, fatal blood clots.In the race to lift the world out of pandemic lockdowns, the Covid vaccine was developed by scientists at the University of Oxford in record time. A process that normally takes 10 years was accelerated down to about 10 months. Oxford vaccine: How did they make it so quickly?In November 2020, it was heralded as “a vaccine for the world” as it was far cheaper and easier to store than other Covid vaccines. The pharmaceutical giant AstraZeneca had agreed to manufacture it on mass.Initially, it was the cornerstone of the UK’s plans to vaccinate our way out of lockdown.”The truth is it made an enormous difference, it was what lifted us out of the catastrophe that was unfolding at the time, combined with the other vaccine from Pfizer,” said Prof Adam Finn, from the University of Bristol. However, its reputation was dented as unusual blood clots emerged as a rare side effect of the vaccine, and the UK turned to alternatives.Covid: Trigger of rare blood clots with AstraZeneca jab found by scientistsIn a statement, AstraZeneca said: “According to independent estimates, over 6.5 million lives were saved in the first year of use alone.”Our efforts have been recognised by governments around the world and are widely regarded as being a critical component of ending the global pandemic.”It said the development of new vaccines that more closely match the mutated forms of Covid that are now circulating meant there was a “surplus of available updated vaccines”, leading to a “decline in demand” for its vaccine which is “no longer being manufactured or supplied”.Prof Finn added: “I think the withdrawal of the vaccine simply reflects it’s no longer useful. “It’s turned out that this virus is very agile and it’s evolved away from the original vaccines, so they have in a sense become irrelevant and only the reformulated vaccines are likely to be being used now.”More on this storyWho can get a Covid booster this spring?Published18 minutes agoScientists find trigger for rare AstraZeneca clotsPublished2 December 2021AstraZeneca faces legal challenge over Covid jabPublished9 November 2023Widow sues AstraZeneca after husband’s vaccine deathPublished22 FebruaryRelated Internet LinksAstraZeneca UK – Biopharmaceutical companyThe BBC is not responsible for the content of external sites.

Published1 day agoShareclose panelShare pageCopy linkAbout sharingImage source, Getty ImagesBy James GallagherInside Health presenter, BBC Radio 4What is it like to catch Covid now? It is a question I have been pondering since a friend was surprised by how roughed up they were by it. Their third bout of Covid was significantly worse than the previous time they caught it. “I thought every time you catch an illness it’s supposed to be a bit better each time?” was the message from his sickbed. That has certainly been said a lot during the pandemic. But I also know work colleagues and people I have interviewed or chatted to at the school gates, who have been hit hard by Covid in the past few months. A familiar tale has been a week of coughing, headaches or fever followed by a lingering fatigue. It is important to stress that Covid has always caused a wide range of symptoms. Even before vaccines, some lucky people barely got sick or did not even develop symptoms. For some of us, Covid is just a sniffle – not even enough to make you go digging around in the bathroom cabinet to see if there is a lateral flow test hiding in there. But scientists specialising in our immune system warn Covid is still causing stonking infections that may be worse than before and knock us out for weeks.So what is going on?How we fare after being exposed to Covid comes down to the battle between the virus itself and our body’s defences. The earliest stages are crucial as they dictate how much of a foothold the virus gets inside our body, and how severe it is going to be. However, waning immunity and the virus evolving are tipping the scales. ‘Feel pretty rough’Prof Eleanor Riley, an immunologist at the University of Edinburgh, has had her own “horrid” bout of Covid that was “much worse” than expected. She told me: “People’s antibody levels against Covid are probably as low now as they have been since the vaccine was first introduced.”Antibodies are like microscopic missiles that stick to the surface of the virus and stop it from infecting our body’s cells. So, if you have lots of antibodies, they can mop up the virus quickly and any infection will hopefully be short and mild.”Now, because antibodies are lower, a higher dose [of the virus] is getting through and causing a more severe bout of disease,” Prof Riley says.Antibody levels are relatively low because it has been a long time since many of us were vaccinated (if you are young and healthy you were only ever offered two doses and a booster) or infected, which also tops up immunity. Prof Peter Openshaw, from Imperial College London, told me: “The thing that made the huge difference before was the very wide and fast rollout of vaccines – even young adults managed to get vaccinated, and that made an absolutely huge difference.”Image source, Getty ImagesThis year even fewer people are being offered the vaccine. Last winter, all over-50s could have one. Now it is only the over-65s, unless you are in an at-risk group. Prof Openshaw says he is not a “doomster”, but thinks the result will be “a lot of people having a pretty nasty illness that is going to knock them out for several days or weeks”.”I’m also hearing of people having nasty bouts of Covid, who are otherwise young and fit. It’s a surprisingly devious virus, sometimes making people quite ill and occasionally leading to having ‘long Covid’,” he says.He thinks there is a “good chance” you are susceptible if you have not caught Covid in the past year.The official government decision in the UK is to vaccinate those at risk of dying from Covid or needing hospital treatment. This relieves pressure on the National Health Service. Prof Riley argues: “But that’s not to say people who are under 65 are not going to get Covid, and are not going to feel pretty rough. “I think the consequence of not boosting those people is we have more people who are off work for a week or two or three over winter.”Decisions on who gets vaccinated are not the only thing to have altered – the virus is also changing.’Little immunity’Antibodies are highly precise as they rely on a close match between the antibody and the part of the virus to which they stick. The more a virus evolves to change its appearance, the less effective the antibodies become. Prof Openshaw said: “The viruses circulating now are pretty distant immunologically from the original virus which was used to make the early vaccines, or which last infected them.”A lot of people have very little immunity to the Omicron viruses and their variants.”Image source, Getty ImagesIf you are feeling rough with Covid – or rougher than you have done before – it could be this combination of waning antibodies and evolving viruses.But this does not mean you are more likely to become critically ill or need hospital treatment. A different part of our immune system – called T-cells – kick in once an infection is already under way and they have been trained by past infections and vaccines.T-cells are less easily befuddled by mutating viruses as they spot cells that have been infected with Covid and kill them. “They will stop you getting severely ill and ending up in hospital, but in that process of killing off the virus there’s collateral damage that makes you feel pretty rough,” says Prof Riley.Relying on your T-cells to clear out Covid is what results in the muscle pain, fever and chills. So where does this leave the thought that Covid is on a trajectory towards becoming a mild, innocuous infection?There are four other human coronaviruses, related to Covid, that cause common cold symptoms. One of the reasons they are thought to be mild is we catch them in childhood and then throughout our lives.Prof Openshaw is clear “we are not there yet” with Covid, but “with repeated infection we should build up natural immunity”.In the meantime will some of us have to suck up a grotty winter?”I fear so,” says Prof Riley.Are you affected by the issues raised in this story? Share your experiences by emailing haveyoursay@bbc.co.uk.Please include a contact number if you are willing to speak to a BBC journalist. You can also get in touch in the following ways:WhatsApp: +44 7756 165803Tweet: @BBC_HaveYourSayUpload pictures or videoPlease read our terms & conditions and privacy policy

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Published11 hours agoShareclose panelShare pageCopy linkAbout sharingImage source, EPABy James GallagherHealth and science correspondentThe Nobel Prize in Physiology or Medicine has been awarded to a pair of scientists who developed the technology that led to the mRNA Covid vaccines. Professors Katalin Kariko and Drew Weissman will share the prize.The technology was experimental before the pandemic, but has now been given to millions of people around the world to protect them against serious Covid-19.The same mRNA technology is now being researched for other diseases, including cancer. The Nobel Prize committee said: “The laureates contributed to the unprecedented rate of vaccine development during one of the greatest threats to human health in modern times.”Vaccines train the immune system to recognise and fight threats such as viruses or bacteria. Traditional vaccine technology has been based on dead or weakened versions of the original virus or bacterium – or by using fragments of the infectious agent. Warning that Covid will ‘continue to surprise us’In contrast, messenger ribonucleic acid (mRNA) vaccines use a completely differently approach. During the Covid pandemic, the Moderna and Pfizer/BioNTech vaccines were both based on mRNA technology. Professor Kariko and Professor Weissman met in the early 1990s when they were working at the University of Pennsylvania, in the United States, when their interest in mRNA was seen as a scientific backwater. “I would go to meetings and present what I was working on, and people would look at me and say: ‘Well, that’s very nice, but why don’t you do something worthwhile with your time mRNA will never work.’. But Katie and I kept pushing,” Professor Wiseman told the BBC’s Newshour programme.Asked about how the pair first reacted to hearing the news that they had won the prize, Professor Kaliko said she thought it was “just a joke” initially.In a similar vein, Professor Weissman said: “I was you know, sort of overjoyed and then disbelief, and a little bit suspecting that there was some anti-vaxxer playing a prank on us.””But when we saw the announcement, we knew it was real and there was just a fantastic feeling.”An mRNA Covid vaccine contains the genetic instructions for building one component – a protein – from the coronavirus.When this is injected into the body, our cells start producing lots of the viral protein. The immune system recognises these as foreign so it attacks and has learned how to fight the virus, and therefore has a head start when future infections occur. The big idea behind the technology is that you can rapidly develop a vaccine against almost anything – as long as you know the right genetic instructions to use. This makes it far faster and more flexible than traditional approaches to vaccine development.There are even experimental approaches using the technology that are teaching patients’ bodies how to fight their own cancers.Scientists analyse a patient’s tumour, look for abnormal proteins being produced by the cancer that are not in healthy tissue and develop a vaccine to target those and inject that into the patient. Profs Kariko and Weissman made the crucial breakthroughs that made mRNA vaccines happen. The principle taps into normal human biology. RNA’s role in our body is to convert the instructions that are locked away in our genetic code, or DNA, into the proteins that our body is built from.However, there were challenges. But by refining the technology, the researchers were able to produce large amounts of the intended protein without causing dangerous levels of inflammation that had been seen in animal experiments. This paved the way for developing the vaccine technology for use in people. Katalin Kariko is now a professor at Szeged University in Hungary and Drew Weissman is still working as a professor at the University of Pennsylvania. Previous Nobel winners2022 – Svante Paabo for his work on human evolution. 2021 – David Julius and Ardem Patapoutian for their work on how the body senses touch and temperature. 2020 – Michael Houghton, Harvey Alter and Charles Rice for the discovery of the virus Hepatitis C.2019 – Sir Peter Ratcliffe, William Kaelin and Gregg Semenza for discovering how cells sense and adapt to oxygen levels2018 – James P Allison and Tasuku Honjo for discovering how to fight cancer using the body’s immune system2017- Jeffrey Hall, Michael Rosbash and Michael Young for unravelling how bodies keep a circadian rhythm or body clock2016 – Yoshinori Ohsumi for discovering how cells remain healthy by recycling wasteSign up for our morning newsletter and get BBC News in your inbox.More on this storyWarning that Covid will ‘continue to surprise us’Published23 hours agoNobel Prize goes to Neanderthal DNA researchPublished3 October 2022UK plan for national mRNA cancer vaccine advancePublished6 January

Published11 minutes agoShareclose panelShare pageCopy linkAbout sharingImage source, University of OxfordBy James GallagherHealth and science correspondentA cheap malaria vaccine that can be produced on a massive scale has been recommended for use by the World Health Organization. The vaccine has been developed by the University of Oxford and is only the second malaria vaccine to be developed. Malaria kills mostly babies and infants, and has been one of the biggest scourges on humanity.There are already agreements in place to manufacture more than 100 million doses a year.It has taken more than a century of scientific effort to develop effective vaccines against malaria. The disease is caused by a complex parasite, which is spread by the bite of blood-sucking mosquitoes. It is far more sophisticated than a virus as it hides from our immune system by constantly shape-shifting inside the human body. That makes it hard to build up immunity naturally through catching malaria, and difficult to develop a vaccine against it.It is almost two years to the day since the first vaccine – called RTS,S and developed by GSK – was backed by the World Health Organization. Two similar vaccinesDr Tedros Adhanom Ghebreyesus, director-general of the WHO, said today was a moment of “great pleasure”.”I used to dream of the day we would have a safe and effective vaccine against malaria, now we have two,” he said.The WHO said the effectiveness of the two vaccines was “very similar” and there was no evidence one was better than the other. However, the key difference is the ability to manufacture the University of Oxford vaccine – called R21 – at scale. The world’s largest vaccine manufacturer – the Serum Institute of India – is already lined up to make more than 100 million doses a year and plans to scale up to 200 million doses a year.So far there are only 18 million doses of RTS,S. The World Health Organization said the new R21 vaccine would be a “vital additional tool”. Each dose costs US$2-4 and four doses is needed per person. That is about half the price of RTS,S.In 2021, there were 247 million cases of malaria and 619,000 people died, most of them children under the age of five. More than 95% of malaria is found in Africa. Life-saving potentialDr Matshidiso Moeti, the WHO regional director for Africa, said: “This second vaccine holds real potential to close the huge demand-and-supply gap. “Delivered to scale and rolled out widely, the two vaccines can help bolster malaria prevention, control efforts and save hundreds of thousands of young lives.”Data that has been published online, but has not been through the usual process of scientific review, shows the R21 vaccine is 75% effective at preventing the disease in areas where malaria is a seasonal disease.The World Health Organization’s strategic advisory group of experts said that figure was comparable to the first vaccine (RTS,S) in seasonal areas.The effectiveness of malaria vaccines is lower in areas where the parasite is present all year round. Prof Sir Adrian Hill, director of the Jenner Institute in Oxford where R21 was developed, said: “The vaccine is easily deployable, cost effective and affordable, ready for distribution in areas where it is needed most, with the potential to save hundreds of thousands of lives a year.”Gareth Jenkins, from Malaria No More UK, said: “The reality is that malaria financing globally is far from where it needs to be and annual deaths from malaria rose during the pandemic and are still above pre-pandemic levels, so we cannot afford to be complacent as new tools are developed.”More on this storyMalaria vaccine is world-changing, say scientistsPublished8 September 2022Ghana first to approve ‘world-changer’ malaria vaccinePublished13 AprilChance discovery helps fight against malariaPublished4 August

Published2 hours agoShareclose panelShare pageCopy linkAbout sharingImage source, Getty ImagesBy James GallagherHealth and science correspondentScientists in the UK and Belgium think they have figured out how brain cells die in Alzheimer’s disease.It has been a mystery and a source of scientific debate for decades.But the team, writing in the journal Science, connect the abnormal proteins that build up in the brain with “necroptosis” – a form of cellular suicide.The findings have been described as “cool” and “exciting”, as they give new ideas for treating the disease.Long-awaited cluesIt is the loss of brain cells, called neurons, that lead to the symptoms of Alzheimer’s, including memory loss.And if you look inside the brains of people with the disease you’d see the build-up of abnormal proteins called amyloid and tau.But scientists have not been able to join the dots between these key traits of the disease.This is what the researchers – at the UK’s Dementia Research Institute at University College London and KU Leuven in Belgium – now think is happening.They say abnormal amyloid starts to build up in the spaces between neurons, leading to brain inflammation, which the neurons do not like. This starts to change their internal chemistry.Tangles of tau appear and the brain cells start producing a specific molecule (it’s called MEG3) that triggers death by necroptosis. Necroptosis is one of the methods our bodies normally use to purge unwanted cells as fresh ones are made.The brain cells survived when the team were able to block MEG3.”This is a very important and interesting finding,” researcher Prof Bart De Strooper, from the UK’s Dementia Research Institute, told the BBC.”For the first time we get a clue to how and why neurons die in Alzheimer’s disease. There’s been a lot of speculation for 30-40 years, but nobody has been able to pinpoint the mechanisms.”It really provides strong evidence it’s this specific suicide pathway.”The answers came from experiments where human brain cells were transplanted into the brains of genetically modified mice. The animals were programmed to produce large quantities of abnormal amyloid.There has been recent success in developing drugs that strip amyloid out of the brain and they mark the first treatments to slow the destruction of brain cells. New drugs for Alzheimer’s hailed as turning pointI’ve got dementia – dementia hasn’t got meFiona Phillips: How common is early Alzheimer’s?Prof De Strooper says the discovery that blocking the MEG3 molecule can hold off brain cell death could lead to a “whole new line of drugs development”.However, this will take years of research.Prof Tara Spires-Jones, from the University of Edinburgh and the president of the British Neuroscience Association, told me “that is a cool paper”.She said it “addresses one of the fundamental gaps in Alzheimer’s research… these are fascinating results and will be important for the field moving forward.”However, she stressed that “many steps are needed” before knowing whether it could be harnessed as an effective treatment for Alzheimer’s.Dr Susan Kohlhaas, from Alzheimer’s Research UK, said the findings were “exciting” but still at an early stage.”This discovery is important because it points to new mechanisms of cell death in Alzheimer’s disease that we didn’t previously understand and could pave the way for new treatments to slow, or even stop disease progression in the future.”ONE OF THE GREATEST SCIENTIFIC THEORIES OF ALL TIME: Join Brian Cox and Robin Ince for a lesson on Einstein’s theory of General Relativity DESERT ISLAND DISCS, RE-SPUN: First broadcast in 1986, Elton John shares the soundtrack of his life in this classic edition More on this storyNew drugs for Alzheimer’s hailed as turning pointPublished17 JulyI’ve got dementia – dementia hasn’t got mePublished13 October 2021Fiona Phillips: How common is early Alzheimer’s?Published5 July

Published26 minutes agoShareclose panelShare pageCopy linkAbout sharingImage source, Weizmann Institute of ScienceBy James GallagherHealth and science correspondentScientists have grown an entity that closely resembles an early human embryo, without using sperm, eggs or a womb. The Weizmann Institute team say their “embryo model”, made using stem cells, looks like a textbook example of a real 14-day-old embryo.It even released hormones that turned a pregnancy test positive in the lab.The ambition for embryo models is to provide an ethical way of understanding the earliest moments of our lives.The first weeks after a sperm fertilises an egg is a period of dramatic change – from a collection of indistinct cells to something that eventually becomes recognisable on a baby scan. This crucial time is a major source of miscarriage and birth defects but poorly understood. “It’s a black box and that’s not a cliche – our knowledge is very limited,” Prof Jacob Hanna, from the Weizmann Institute of Science, tells me.Starting materialEmbryo research is legally, ethically and technically fraught. But there is now a rapidly developing field mimicking natural embryo development.This research, published in the journal Nature, is described by the Israeli team as the first “complete” embryo model for mimicking all the key structures that emerge in the early embryo. “This is really a textbook image of a human day-14 embryo,” Prof Hanna says, which “hasn’t been done before”.Instead of a sperm and egg, the starting material was naive stem cells – reprogrammed to gain the potential to become any type of tissue in the body. Chemicals were then used to coax these stem cells into becoming four types of cell found in the earliest stages of the human embryo:epiblast cells, which become the embryo proper (or foetus)trophoblast cells, which become the placentahypoblast cells, which become the supportive yolk sac extraembryonic mesoderm cellsA total of 120 of these cells were mixed in a precise ratio – and then, the scientists step back and watch. About 1% of the mixture began the journey of spontaneously assembling themselves into a structure that resembles, but is not identical to, a human embryo.”I give great credit to the cells – you have to bring the right mix and have the right environment and it just takes off,” Prof Hanna says. “That’s an amazing phenomenon.” Synthetic human embryo raises ethical issuesSynthetic mouse embryo develops beating heartThe embryo models were allowed to grow and develop until they were comparable to an embryo 14 days after fertilisation. In many countries, this is the legal cut-off for normal embryo research. Despite the late-night video call, I can hear the passion as Prof Hanna gives me a 3D tour of the “exquisitely fine architecture” of the embryo model.I can see the trophoblast, which would normally become the placenta, enveloping the embryo. And it includes the cavities – called lacuna – that fill with the mother’s blood to transfer nutrients to the baby. There is a yolk sac, which has some of the roles of the liver and kidneys, and a bilaminar embryonic disc – one of the key hallmarks of this stage of embryo development.’Making sense’The hope is embryo models can help scientists explain how different types of cell emerge, witness the earliest steps in building the body’s organs or understand inherited or genetic diseases.Already, this study shows other parts of the embryo will not form unless the early placenta cells can surround it.There is even talk of improving in vitro fertilisation (IVF) success rates by helping to understand why some embryos fail or using the models to test whether medicines are safe during pregnancy. Prof Robin Lovell Badge, who researches embryo development at the Francis Crick Institute, tells me these embryo models “do look pretty good” and “do look pretty normal”.”I think it’s good, I thinks it’s done very well, it’s all making sense and I’m pretty impressed with it,” he says.But the current 99% failure rate would need to be improved, he adds. It would be hard to understand what was going wrong in miscarriage or infertility if the model failed to assemble itself most of the time. Legally distinctThe work also raises the question of whether embryo development could be mimicked past the 14-day stage. This would not be illegal, even in the UK, as embryo models are legally distinct from embryos. “Some will welcome this – but others won’t like it,” Prof Lovell-Badge says.Prof Alfonso Martinez Arias, from the department of experimental and health sciences at Pompeu Fabra University, said it was “a most important piece of research”.”The work has, for the first time, achieved a faithful construction of the complete structure [of a human embryo] from stem cells” in the lab, he said, “thus opening the door for studies of the events that lead to the formation of the human body plan”.The researchers stress it would be unethical, illegal and actually impossible to achieve a pregnancy using these embryo models – assembling the 120 cells together goes beyond the point an embryo could successfully implant into the lining of the womb.Follow James on Twitter.More on this storySynthetic human embryo raises ethical issuesPublished15 JuneRelated Internet LinksNature journalThe BBC is not responsible for the content of external sites.

Published8 hours agoShareclose panelShare pageCopy linkAbout sharingImage source, Getty ImagesBy James GallagherHealth and science correspondentAdvice on how much aspartame we can eat or drink is unchanged, despite the sweetener being classified as “possibly” causing cancer. Two groups of experts at the World Health Organization have been reviewing thousands of scientific studies. The “possibly carcinogenic” label often causes fear and confusion, but just means the evidence is unconvincing. Most people consume less than the safe upper limits of aspartame, but the WHO recommends heavy consumers cut down.Aspartame is found in diet and sugar-free versions of foods, as the chemical gives a taste 200 times sweeter than sugar for little calories.Famous brands containing the sweetener include Diet Coke, Coke Zero, Pepsi Max and 7 Up Free, but aspartame is in around 6,000 products ranging from toothpaste and chewing gums to yoghurts and cough sweets.Despite being so widespread, the chemical’s safety has been a source of controversy since it was introduced in the 1980s.I asked Dr Francesco Branca, the director of the department of nutrition and food safety at the World Health Organisation (WHO), what was the healthier choice: sugar or sweetener? He told me: “Faced with a decision of whether to take cola with sweeteners or one with sugar, I think there should be a third option, which is to drink water instead and to limit the consumption of sweetened products altogether.”He said the reviews had “raised the flag” that aspartame may not be great for your health, but said you “shouldn’t have a concern” about an occasional diet drink or other product containing the sweetener, adding “the problem is for high consumers”. The first body to assess the evidence was the WHO’s cancer experts – the International Agency for Research on Cancer.IARC uses four possible classifications: Group 1 – Carcinogenic (cancer causing) to humansGroup 2A – Probably carcinogenic to humansGroup 2B – Possibly carcinogenic to humansGroup 3- Not classifiable It has moved aspartame into the “possibly carcinogenic” category alongside other substances such as aloe vera and lead. This decision largely centres on three studies suggesting a connection to a type of liver cancer. However, the “possibly” refers only to the strength of scientific evidence. If the evidence was strong, then aspartame would be in a higher category.Dr Mary Schubauer-Berigan, of the International Agency for Research on Cancer, said the “evidence was not of sufficiently high quality or convincing enough” and “this is really more a call to the research community” to study the sweetener more. The cancer classifications frequently lead to misleading headlines. Alcohol and plutonium are in the same category (both are proven to cause cancer), but one is seriously more dangerous than the other. So a separate body – the World Health Organization and the Food and Agriculture Organization Joint Expert Committee on Food Additives – has the job of working out safe doses.It analysed the cancer risk as well as other issues such as heart disease and type 2 diabetes, but found “no sufficient reason” to alter the advice it has had since 1981.So the safe limits remain at 40 milligrams per kilogram of your body weight, per day. These aren’t targets, they’re the upper safety limits. But as the advice is based on body weight, it is easier for children to get close to the limit.Dr Branca said it was “not a good practice” to have a bottle of sweet fizzy drink on the table at family dinner time, as children risked being set up with a sweet tooth for life. He also stressed that large reviews of the evidence show sweeteners do not help people lose weight.So his advice is for everyone to shift to a less sweet diet – cutting both sugar and sweeteners – and for companies to produce foods that are less sweet, but still tasty.One of the big outstanding research questions is how might aspartame result in cancer (if indeed it does). The WHO reports show that aspartame itself is rapidly broken down in the gut into three other substances – phenylalanine, aspartic acid and methanol.But these are also the product of digesting a wide variety of other foods that are not linked with cancer. And the researchers concluded that aspartame is not directly making cancerous mutations in people’s DNA. Raising levels of inflammation in the body is one possibility. Frances Hunt-Wood, secretary general of the International Sweeteners Association, said the work had “once again reaffirmed aspartame’s safety”.She added: “Aspartame, like all low/no calorie sweeteners, when used as part of a balanced diet, provides consumers with choice to reduce sugar intake, a critical public health objective.”There are some people who cannot safely consume aspartame. These are people with an inherited disease called phenylketonuria or PKU, who are born unable to metabolise the phenylalanine that is released as aspartame is broken down. Follow Jameson Twitter.More on this storyAspartame – is it a possible cause of cancer?Published29 June

Published17 minutes agoShareclose panelShare pageCopy linkAbout sharingImage source, Getty ImagesBy James GallagherHealth and science correspondentThe sweetener aspartame – found in a variety of foods – is set to be officially labelled as “possibly carcinogenic to humans”, reports claim. The classification frequently causes confusion and does not tell us how risky consuming aspartame actually is.Other “possibly carcinogenic” substances include aloe vera, diesel and pickled Asian vegetables. The BBC understands the International Agency for Research on Cancer (IARC) will make an announcement on 14 July. What has aspartame in it?Aspartame is 200 times sweeter than sugar, so it gives the taste without the calories. You will find it on the ingredients list of many diet or sugar-free foods including diet drinks, chewing gums and some yoghurts. The sweetener has been used for decades and approved by food safety bodies, but there has been a swirl of controversy around the ingredient.IARC, the cancer research arm of the World Health Organization, has been reviewing about 1,300 studies on aspartame and cancer. The Reuters news agency says it has spoken to sources close to the process, and aspartame will be classified “possibly carcinogenic”.The BBC understands official announcements will be made by IARC and a separate expert committee on food additives – alongside a publication in the Lancet Oncology medical journal on 14 July. IARC uses four possible classifications: Group 1 – Carcinogenic to humansGroup 2A – Probably carcinogenic to humansGroup 2B – Possibly carcinogenic to humansGroup 3- Not classifiable However, this is where it can get confusing. “The IARC categorisation won’t tell us anything about the actual level of risk from aspartame, because that’s not what IARC categorisations mean,” says Kevin McConway, professor of statistics at the Open University.IARC tells us how strong the evidence is, not how risky a substance is to your health. The “possibly” category is used when there is “limited” evidence in people or data from animal experiments. It includes diesel, talc on the perineum, nickel, aloe vera, Asian pickled vegetables and a host of chemical substances. “I emphasise though that the evidence that these things could cause cancer is not very strong or they would have been put in group 1 or 2A,” added Prof McConway. The IARC classifications have caused confusion in the past, and have been criticised for creating unnecessary alarm. When processed red meat was categorised as carcinogenic, it led to reports equating it to smoking. But the risk of giving 100 people an extra 1.7oz (50g) of bacon – on top of any they already eat – every single day for the rest of their lives would lead to one case of bowel cancer.We do not have the equivalent numbers for aspartame, however, the Joint World Health Organization and Food and Agriculture Organization’s Expert Committee on Food Additives is due to report in July. Its stance since 1981 has been a daily intake of 40 milligrams, per kilogram of your body weight, per day was safe. That works out at between 12 and 36 cans of diet drinks (depending on the exact ingredients) a day for a 60 kg (nine-and-a-half stones) adult.The International Council of Beverages Associations’ executive director Kate Loatman said public health authorities should be “deeply concerned” by the “leaked opinion”, and also warned it “could needlessly mislead consumers into consuming more sugar, rather than choosing safe no-and low-sugar options”.Rick Mumford, the deputy chief scientific adviser to the UK’s Food Standards Agency, said the body would “closely study” the reports, but “our view is that the safety of this sweetener has been evaluated by various scientific committees and it is considered safe at current permitted use levels”.A study in the early 2000s linked it to cancer in mouse and rat experiments, but the findings were criticised and other animal studies have not found a cancer risk. Last year a study of 105,000 people compared people who consumed no sweeteners with those who consumed large amounts. High levels of sweeteners – including aspartame – were linked to a higher risk of cancer, but there are many differences in the health and lifestyles between the two groups. There are some people who cannot safely consume aspartame. These are people with an inherited disease called phenylketonuria or PKU.People with PKU are unable to metabolise a component of aspartame.Follow James on Twitter.

Published13 minutes agoShareclose panelShare pageCopy linkAbout sharingImage source, ReutersBy James GallagherHealth and science correspondentA key defence that blocks nearly all bird flu when it attempts to invade our body has been discovered by scientists. Bird flus have been involved in four pandemics since 1918 – killing millions of people.The research, led by the University of Glasgow, showed those pandemics and normal winter flus had evolved ways of getting round this “powerful barrier”. The team think we will soon be able to predict which of the flus currently in birds pose the biggest risk.The scientists were investigating spillover events. These are the moments a person catches an infection from an animal. This jump across species is a critical step in the start of a new pandemic. Listen: The Jump on BBC SoundsIn laboratory experiments, researchers uncovered a section of our genetic code – our DNA – that becomes activated in response to an infection. It is called BTN3A3 (although even the researchers admit “we’re stuck” with a clunky name). The data, published in the journal Nature, showed BTN3A3 became active in our nose, throat and lungs and that it reduced the ability of bird flus to replicate. Researcher Dr Rute Maria Pinto said “nearly all” bird flus are unable to bypass this protection so “these are normally blocked by it, so they don’t jump”.She added: “The big majority of human viruses and in fact all pandemic viruses so far, have [resistance to BTN3A3] so they overcome this block and therefore infect.”There is a constant chance of bird flus making the jump into people. There is a variety of flu viruses in wild birds, and poultry poses a high risk because of the sheer number of farmed animals and their close proximity to people. The 1918 flu pandemic is thought to have started in birds and is estimated to have killed 50 million people. The researchers showed a form of bird flu called H7N9 developed higher levels of resistance to BTN3A3 in 2011 and 2012 before the first human cases emerged in 2013.Evolving ways of bypassing BTN3A3 is one of the steps a bird flu can take to successfully infect us. The researchers’ vision is to routinely analyse – or sequence – the genetic code of flus that are currently circulating in birds, identify the dangerous ones and tackle them. Image source, PA MediaProf Massimo Palmarini, director of the Centre for Virus Research in Glasgow, told me: “In the not so distant future we’ll be able to put together all the pieces of the puzzle.”From a sequence of a virus, we’ll be able to say this has a 90% chance to cross over to humans, this virus has only a 10% chance.”Then targeted measures could be introduced to help control viruses that do have a high risk of making the jump.The current outbreak?The world’s bird populations have been hit by the largest bird – or avian – flu outbreak ever recorded. Bird flu outbreak: What is it and what’s behind it?Bird flu: Brazil declares animal health emergencyThe virus – H5N1 – has occasionally jumped into people coming into close contact with infected animals, but it has not spread from one person to another. Prof Palmarini said “a bit more than 50%” of virus samples from birds and “all seven” cases detected in people this year had resistance to BTN3A3.”That is one layer of concern, the other is the virus has spread as never before,” he told me. However, the ability to bypass BTN3A3 is only one aspect of the virus’s threat to human health.Dr Stephen Oakeshott, the head of infections and immunity at the Medical Research Council, said: “This interesting study illustrates an important piece of the very complex puzzle underpinning viral transmission between species.”This type of mechanistic scientific insight, coupled with genetic surveillance, can offer a window into future disease risks to inform public health planning.”Follow James on Twitter.

Published31 minutes agoShareclose panelShare pageCopy linkAbout sharingImage source, Getty ImagesBy James GallagherHealth and science correspondentRegularly finding time for a little snooze is good for our brain and helps keep it bigger for longer, say University College London researchers.The team showed nappers’ brains were 15 cubic centimetres (0.9 cubic inches) larger – equivalent to delaying ageing by between three and six years. However, the scientists recommend keeping naps to less than half an hour.But they said a daytime sleep was hard in many careers, with work culture often frowning on the practice. “We are suggesting that everybody could potentially experience some benefit from napping,” Dr Victoria Garfield told me. She described the findings as “quite novel and quite exciting”.Napping has been shown to be critical for development when we are babies, becomes less common as we age and then goes through a resurgence in popularity after retirement, with 27% of people over 65 reporting having a daytime nap. Dr Garfield says advice to nap is “something quite easy” to do in comparison to weight loss or exercise which are “difficult for a lot of people”.The brain naturally shrinks with age, but whether naps could help prevent diseases like Alzheimer’s will still need extra research. Overall brain health is important for protecting against dementia and the condition is linked to disturbed sleep.The researchers suggest poor sleep is damaging the brain over time by causing inflammation and affecting the connections between brain cells. “Thus, regular napping could protect against neurodegeneration by compensating for deficient sleep,” researcher Valentina Paz said.However, Dr Garfield is not about to find a comfy spot to snooze at work and prefers other ways of looking after her brain.”Honestly, I would rather spend 30 minutes exercising than napping, I’ll probably try and recommend that my mum does it.” How to find the answer?Studying napping can be a challenge. Napping might boost health, but the reverse is also true as your health can leave you so tired you need to nap more. So the researchers used a clever technique to prove that napping is beneficial. They used a gigantic natural experiment based on the DNA – the genetic code – with which we are born. Previous studies have identified 97 snippets of our DNA that either make us more likely to be nappers or to power through the day. So the team took data from 35,000 people, aged 40 to 69, taking part in the UK Biobank project and simply compared those genetic “nappers” and “non-nappers”.The results, published in the journal Sleep Health, showed a 15 cubic centimetre difference – equivalent to 2.6 to 6.5 years of ageing. Total brain volumes were about 1,480 cubic centimetres in the study. “I enjoy short naps on the weekends and this study has convinced me that I shouldn’t feel lazy napping, it may even be protecting my brain,” Prof Tara Spires-Jones, from the University of Edinburgh and the president of the British Neuroscience Association, told me.She said the “interesting” findings study showed a “small but significant increase in brain volume” and “adds to the data indicating that sleep is important for brain health”.The researchers did not directly study having a big sleep in the middle of the day, but said the science pointed towards a cut off of half an hour. Follow James on Twitter.