‘Ferritin face’: what you need to know about low iron

Madeleine Finlay and co-host Ian Sample discuss the three science stories you need to know about this week, including an alternative to BMI for diagnosing obesity which could ‘prevent misdiagnosis for millions’. Also on the agenda: an update from this year’s Cop climate conference in Turkey, and a study that claims to have found the key to better conversations with the help of a concept from physics. Help support our independent journalism at theguardian.com/sciencepod

As the nights draw in, many of us can experience low mood. But for a small proportion of people a more intense depression develops through the winter months. It’s a phenomenon that since the 1980s has been labelled seasonal affective disorder, or Sad, and can be debilitating for sufferers. To find out more about the latest scientific understanding of Sad, Ian Sample speaks to Russell Foster, professor of circadian neuroscience at the University of Oxford. He explains what scientists think the mechanism for the condition could be and what the evidence says about the best way to tackle it. • In the UK and Ireland, Samaritans can be contacted on freephone 116 123. In the US, you can call or text the 988 Suicide & Crisis Lifeline at 988 or chat at 988lifeline.org. In Australia, the crisis support service Lifeline is 13 11 14. Other international helplines can be found at befrienders.org. Help support our independent journalism at theguardian.com/sciencepod

When the water in Flint, Michigan, became contaminated with dangerous levels of lead, Dr Siddhartha Roy, then a third year PhD student, was part of the team of scientists who publicly contradicted state and federal claims that it was safe. He became a local hero until a new piece of research challenged the idea that children in Flint had been left permanently brain damaged by the crisis. His adherence to the evidence, no matter who it offended, has earned him the 2026 Maddox prize, which recognises individuals who stand up for science and evidence, despite challenges or hostility. He tells Ian Sample how he reflects on his experience in Flint, and why he lost friends as a result of his work there. Help support our independent journalism at theguardian.com/sciencepod

As one of the world’s leading forensic anthropologists, Dame Sue Black has acted as an expert witness in a myriad of high-profile criminal cases. Her work has taken her from the lab to active war zones and the aftermath of natural disasters to identify victims’ bodies. Speaking to Ian Sample, the professor explains why standing up in front of a judge and jury has been one of the more terrifying parts of her career, the reputational risk of presenting evidence in court and what the future of forensic science could look like. Help support our independent journalism at theguardian.com/sciencepod

Perimenopause has become a hot topic, with celebrities sharing their experiences and doctors offering tips and advice online. But despite the benefits of growing awareness, a rising number of women are now encountering misinformation about treatments such as HRT. Madeleine Finlay hears from Dr Paula Briggs, a consultant in sexual and reproductive health, about why experts have raised the alarm. Science correspondent Nicola Davis gives the facts on symptoms, tests and treatments. Help support our independent journalism at theguardian.com/sciencepod