Episode 350

What If Alzheimer’s disease starts in the body, not the brain? A radical new theory upends everything we thought we knew about the disease. Alzheimer’s is the most common form of dementia - the leading cause of death in the UK. And for 100 years we believed it all happened in the brain.

Despite all of the major symptoms of Alzheimer’s being brain related, scientists studying gene activity have discovered something surprising. Most risk variants for the disease appear in the skin, lungs and gut - not the brain.

This could mean the leading suspects of the disease - amyloid plaques and tau proteins - may not be to blame. But if not them, then what?

Rowan Hooper is joined by New Scientist’s Australia reporter Alice Klein to discuss the findings.

Chapters

(00:00) Intro - A radical new understanding of Alzheimer’s

(01:23) Why amyloid and tau treatments aren’t proving effective

(02:16) How gum and dental health is linked to Alzheimer’s

(03:09) Could proteins in the brain be a protective feature?

(03:56) Why amyloid and tau really aren’t the full picture

(04:35) Why scientists have gone back to the drawing board

(05:37) Does Alzheimer’s start in the skin, lungs and gut?

(06:14) Alzheimer’s risk genes found in the immune system and barrier tissues

(07:12) Where inflammation fits into the puzzle of Alzheimer’s

(09:10) The role of the blood brain barrier

(10:00) How have scientists responded to these findings?

(10:58) What other health conditions are linked to Alzheimer’s?

(12:08) Preventative measures you can take to reduce your Alzheimer’s risk

(15:03) How reframing diseases leads to better treatments

To read more about these stories, visit https://www.newscientist.com/

Read the latest New Scientist CoLab article: https://newscientist.com/eternal

Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 349

One of the most vital systems of ocean currents - needed to keep life in northern Europe stable - is at risk of collapse. And now we can predict when it’s going to happen.

Thanks to the work of climate scientists, we now have a model that tells us when major shifts in the Atlantic Meridional Overturning Circulation (AMOC) are expected. The AMOC is the Atlantic conveyor belt that keeps northern Europe temperate. If it turns off, northern Europe would be plunged into freezing conditions that would decimate agriculture and upend life as we know it. And it’s becoming clear that it is already weakening.

Rowan Hooper is joined by climate journalist Alec Luhn. Together they explain how the AMOC and gulf stream work, why fears of a “tipping point” have been growing in recent years, and how this new model helps us prepare for the worst.

Also hear from climate scientist René van Westen, who co-authored the report in Nature.

To read more about these stories, visit https://www.newscientist.com/

Listen to the latest episode of New Scientist CoLab: https://newscientist.com/eternalpod 

Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 348

Thought extinct for 6,000 years, two marsupial species have been discovered alive in New Guinea. Biologists have found a new genus of marsupial glider and the Pygmy Long-fingered Possum on a small Western part of the island.

One biologist said this discovery was “more important than finding a living Thylacine in Tasmania”.

Host Rowan Hooper is joined by Tim Flannery of the Australian Museum in Sydney, who led the team that confirmed the discovery. He tells us all about these quirky and cute creatures, one of which is held up as sacred by some Indigenous communities - who won’t even utter its name in public.

Learn about the glider’s habit of forming monogamous relationships and its gardening prowess. And discover why the long-fingered possum’s finger is so long.

Other key players in this research are Professor Kris Helgen, multiple researchers from the University of Papua - and some of the local villagers.

To read more about these stories, visit https://www.newscientist.com/

Glider image credits: Dewa, Australian Museum

Other image credits: Flannery et al

Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 347

Drones have taken over the battlefield in Russia’s war on Ukraine. Tens of thousands of drones are being produced every day - operating as kill vehicles for both sides. Multiple types are being deployed, including flying artillery drones and ground drones.

Now the deadliest war since World War 2 - and considered the first “drone war” - the conflict is being fought in a way unlike we’ve ever seen before. With more than 80 per cent of military hits now made by drones. So on this special edition of the podcast we ask: is this the future of warfare? 

Driving these vehicles is in some ways like playing a video game, with operators sitting behind a screen with a handheld controller. And the gamification goes beyond this, with drone operators earning “points” for kills - that can be cashed in for more military equipment. AI is increasingly used to guide drones and to analyse targets. 

Joining hosts Rowan Hooper and Penny Sarchet are Matt Sparkes, who’s recently returned from a drone factory in Ukraine, and Serhii Andriev, Deputy Company Commander of “Kraken” 3rd Army Corps drone regiment. 

The team also hear from Andrii Hrytseniuk, CEO of Ukraine government organisation Brave 1 - and Trusta, an Ukrainian engineer and drone pilot trainer.

To read more about these stories, visit https://www.newscientist.com/

Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 346

The world is running out of water, with many countries suffering from significant water shortages. We’re now having to rely on groundwater that takes thousands of years to replenish – so what can we do? One group says, to save us from worldwide “water bankruptcy”, we need to artificially change the weather. Although “cloud-seeding” has been around for a long time, a new technique is getting big results in the US. But the idea is becoming increasingly controversial – with cloud-seeding held responsible for recent floods in Dubai and Texas. So will this help, or hurt?

Grief is a very normal experience for those who suffer a loss. But for 1 in 20 of us, this intense sadness doesn’t go away. “Prolonged grief disorder” was recognised as a distinct psychiatric condition in 2022 – but it was controversial, with some concerned we’re pathologising a normal human response. But new research suggests there really are unique things happening in the brains of those suffering from PGD. Could this help us find better ways to treat the condition?

Is the black hole in the centre of our universe actually a massive clump of dark matter? It seems ridiculous to ask, but the new theory is genuinely worth investigating. Researchers say Sagittarius A* is just the right size that it could defy everything we think we know about it. Could we have an answer to the puzzle of dark matter, right on our doorstep?

Hosted by Penny Sarchet and Timothy Revell, with guests Alec Luhn, Alexandra Thompson and Leah Crane.

To read more about these stories, visit https://www.newscientist.com/

Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 345

More than 8,500 years ago, ancient people crossed the ocean to the remote island of Malta for the first time. Long before compasses or sails were invented, these prehistoric people navigated the seas on logs, using the stars to travel vast distances. Recent findings show we’ve long underestimated the voyaging capabilities of stone-age hunter-gatherers. We discuss the many examples of ancient travel - and what this all tells us about the ancient mind.

Could just one hour of brain training a day be enough to stave off dementia? For the first time, an intervention against dementia has been tested in a randomised control trial. Lasting an impressive 20 years, participants in the trial played a brain training game for just a few hours a week - and the results were remarkable.

The legendary space scientist Maggie Aderin joins the show to discuss her new book, Starchild: My Life Under the Night Sky. The Sky at Night presenter discusses her motivation for writing a memoir, how her love of astronomy came about, what it was like as the only Black woman in her university class, her time working on the James Webb telescope - and more.

Hosted by Rowan Hooper and Penny Sarchet, with guests Maggie Aderin, Michael Marshall and Alexandra Thompson.
To read more about these stories, visit https://www.newscientist.com/

Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 344

Elon Musk has announced he wants to merge SpaceX with another of his companies, xAI, and launch one million satellites into space. One reason - according to Musk - is to eventually harness the entire power of the sun, a sci-fi sounding idea that would make us a Kardashev Type II civilisation. But he also wants the satellites to help power AI and move data centres off Earth. Is his goal realistic… and what would be the consequences?

Parents desperate to get their children to sleep are resorting to melatonin gummies - and it’s proving very effective. Melatonin is a sleep hormone which is only available on prescription in many countries. So some parents are importing them from America - where they can be bought over-the-counter. The trouble is the long-term side effects are not really known - and cases of melatonin overdose in children are on the rise.

Despite global agreement to cut the "overall risk" from pesticides by at least half by 2030 - new data shows we’re not even close. Countries made this commitment at a UN biodiversity meeting in 2022, but so far it’s been almost impossible to measure success. Thanks to a researcher in Germany, we now have a way to track our progress - and it’s not looking good. Could an increase in organic farming be the solution, or CRISPR gene editing?

Hosted by Rowan Hooper and Penny Sarchet, with guests Jonathan O’Callaghan, Alice Klein and Michael Le Page.

To read more about these stories, visit https://www.newscientist.com/

Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 343

The task of growing human brains in a lab has taken a step forward. Scientists have been creating brain organoids since 2013, but have now grown blood vessels in them for the first time. These mini brains resemble the developing cortex - the area of the brain that thinks, feels and stores memories. These advancements will help us learn more about the brain and conditions like dementia. But what if we go too far and they become conscious?

Geoengineering is being talked about more and more as countries fail to hit emissions targets. Without reductions we are on course to hit 4.5°C of warming by 2100, so new solutions are needed. But will artificially cooling the climate really help, or do even more damage? One popular method is solar radiation management - but that would require at least 100 aircraft working for hundreds of years. And new research shows that while it could work, the moment we stop doing temperatures would rebound rapidly. So is it worth even trying?

An incredible trove of ancient fossils have been discovered in a quarry in China, dating from 512 million years ago, just after Earth’s first mass extinction event. More than 8000 fossils have been analysed and nearly 60 per cent of the species are new to science. This group of arthropods, molluscs and brachiopods contain some very weird and wonderful creatures - including one which looks remarkably like a penis with long branching tentacles growing out of the end.

Hosted by Rowan Hooper and Penny Sarchet, with guests Carissa Wong, Alec Luhn and Sam Wong.

To read more about these stories, visit https://www.newscientist.com/

Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 342

Social media began with the best intentions - but it soon went sour. Platforms that once fostered connection are now driven by an endless desire to monopolise our time. From the endless scroll to ragebait content, social media is no longer designed to connect us with friends and family - but to profit from our attention. And that’s not to mention the damaging political influence it can have. As countries and governments move to act against it, is there a good solution to these problems?

Bitcoin is one big disaster for the environment. Mining bitcoin requires an inordinate amount of energy - and that cost only increases as more bitcoin is mined. It’s also a terrible investment these days, with some experts suggesting you’d be better off buying a load of Pokémon cards. Adding to that its role in fuelling crime on the dark web - and it becomes a strong contender for worst idea of the 21st century.

Carbon off-sets - another well intentioned solution to the climate crisis that’s gone horribly wrong. The idea is you can lessen the environmental impact of your actions, by off-setting the damage. Maybe you take a long-haul flight, but you plant a tree in return. The trouble is, not only does this give people permission to keep polluting the environment, it’s not even clear if offsetting actually works. But perhaps it’s not all bad?

Effective altruism is a surprising addition to the list, given that it’s meant to be a way of ensuring money goes to only the best causes. But judging which charities deserve donations above others is much more difficult than it seems. And part of the effective altruism movement suggests people should earn as much money as possible so they can one day give it away - which can obviously end badly. And then there are those who have taken it too far - ruining their life.

One seemingly good fix for environmental damage is the promise of alternative fuels, like natural gases, hydrogen and biofuels. But it turns out they probably do a lot more damage than good. Biofuels in particular require massive amounts of farmland to produce, which alone is highly polluting. Add to that the fact they’re driving up prices at the supermarket - perhaps there’s a better way to stop the climate from warming?

Hosted by Rowan Hooper and Abby Beall, with guests Matt Sparkes, Leah Crane, Michael Le Page and Joshua Howgego.
To read more about these stories, visit https://www.newscientist.com/

Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 341

"The best minds of my generation are thinking about how to make people click ads. That sucks." A compelling quote that sums up the thesis of Rutger Bregman’s new book. In Moral Ambition, the Dutch historian and the best-selling author argues that smart people need to stop wasting their lives in “BS” jobs - and turn their skills to causes that benefit humanity. By reflecting on the history of the abolitionist and women’s rights movements, he explains why it’s never too late to take action on major issues - like climate change or the exploitation of animals. He also explores how AI experts are preparing for a massive shift in the way we live, that we need to pay attention to.

Same-sex sexual behaviour in primates is incredibly common - despite seemingly having no evolutionary advantage. But scientists have now noticed something counterintuitive. This behaviour happens more often in high-stress environments, where food is scarce, suggesting it may aid with social cohesion. It may even improve the success of straight sex - increasing the number of offspring in a group.

If you want to live a longer, healthier life - it may be way easier than you think. Most modern longevity advice is about optimising every aspect of your life - and can feel overwhelming for many people. But a new study shows you can add a full year to your life, just by making very minor tweaks to things like sleep and exercise. Find out how.

For three years in a row, average global temperatures have exceeded 1.5 degrees Celsius above preindustrial temperatures. As we fail to get a handle on rising global heating, scientists are exploring a new - slightly odd - way of managing carbon levels. The idea is to protect Earth’s climate from future wildfires, but cutting down vast swathes of forest and sinking the trees in the Arctic ocean. But will it work - or make things worse?

Hosted by Rowan Hooper with guests Rutger Bregman, Michael Le Page, Carissa Wong and Alec Luhn.

To read more about these stories, visit https://www.newscientist.com/

Learn about New Scientist CoLab and ViiV Healthcare’s roundtable discussion here: [email protected]

Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 340

Acquiring Greenland has been deemed a national security priority by America. President Trump wants to use the country to deter adversaries in the Arctic, have control over its rare minerals and oil - and maybe even build experimental cities. But with the challenges of a changing climate, difficulty actually extracting any natural resources and the fact that Greenland isn’t free to occupy, how realistic are Trump's goals? 

Human-plant hybrid cells are being used to answer the mystery of “dark DNA”. Also known as “junk DNA”, this refers to the fact that much of the human genome seems to be inactive. And this new experiment may have proven this claim, showing that only about 10 per cent of our DNA is useful…the rest is just rubbish. What does that mean for the story of evolution, or the future of genetic modification? The team explores two major ways to interpret the results.

And two diet-related stories this week. First, that fibre seems to have a beneficial effect on sleep quality, according to a large observational study review. And second, how people who stop taking GLP-1 weight-loss drugs, like Ozempic and Wegovy, tend to regain the weight they lost within less than two years.

Hosted by Rowan Hooper and Penny Sarchet, with guests Michael Le Page, Alexandra Thompson, Anna Merril, Ruth Mottram and Martin Stendel.
To read more about these stories, visit https://www.newscientist.com/

Learn more about your ad choices. Visit megaphone.fm/adchoices