Welcome to Peer Review'd, the podcast where we break down the latest science news and make it actually make sense. I'm your host, and wow, do we have a packed episode for you today. From ancient fossils rewriting evolutionary history, to breakthroughs in Alzheimer's treatment, to astronauts fixing toilets in space — yes, really — let's dive in.

Let's start with some big news from the medical world. A major clinical trial is offering reassurance to parents about two of the most common infant medications: acetaminophen — that's Tylenol — and ibuprofen, like Advil. Earlier studies had raised concerns about potential developmental effects. But new findings are pushing back on that worry, showing reassuring early results. If you've ever anxiously given your feverish baby a dose of Tylenol at 2 AM, this is the kind of study you want to hear about.

And here's something wild: your sweat might actually be protecting you from the flu. Scientists at the Fisabio Foundation have discovered that dermcidin — a peptide your body continuously produces — doesn't just fight bacteria and fungi. It also shows antiviral activity against influenza, interfering with the virus at one of its most critical steps. Basically, your skin is running its own quiet antiviral defense system. Science is incredible.

Now let's talk Alzheimer's, because there were multiple major developments this week. First, researchers at the University of Barcelona have developed an experimental drug called FLAV-27 that takes a completely different approach from existing treatments. Instead of just clearing the beta-amyloid plaques we typically associate with the disease, this compound targets gene regulation — essentially rewiring the brain at a molecular level. It's early days, but the concept is genuinely exciting.

And separately, scientists are exploring a surprisingly simple screening tool: a nasal swab. Research out of Duke Health suggests that a routine outpatient nose swab could detect early biological signals of Alzheimer's years before symptoms even appear. Early detection has always been one of the biggest challenges with this disease, so a low-cost, accessible test like this could be a real game-changer.

There's also a fascinating — and somewhat surprising — dietary finding. A new study found that older adults carrying high-risk APOE gene variants, which are associated with Alzheimer's, actually showed slower cognitive decline if they ate relatively high amounts of meat. This challenges conventional dietary advice and suggests that genetics may play a much bigger role in how diet affects brain health than we previously thought. Context, as always, matters enormously.

Moving to equally exciting news — a new gene therapy is giving people born deaf the ability to hear, sometimes within just weeks of a single injection. In a small but groundbreaking study, all ten patients — ranging from young children to adults — experienced improved hearing after researchers delivered a working copy of a key hearing gene directly into the inner ear. Some showed rapid gains in as little as one month. One injection. Weeks. That's remarkable.

Also on the treatment front, a clinical trial found that a fasting-mimicking diet — just five days a month of low-calorie, plant-based meals — led to noticeable improvements for most Crohn's disease patients. And it didn't just reduce symptoms. It also lowered biological markers of inflammation in the body. For a disease that has long lacked clear dietary guidance, this is a meaningful step forward.

Now let's shift gears to something that might make you rethink your wardrobe choices — especially if you have young kids. Researchers testing children's shirts from multiple retailers found that every single sample exceeded U.S. safety limits for lead. Every one. Brightly colored fabrics like red and yellow were particularly high. And since young children often chew on their clothing, the exposure risk is real. Fast fashion, it turns out, may come with a hidden toxic price tag.

Here's another health headline that's hard to ignore: a new study says BMI is getting it wrong for more than one-third of adults. By comparing BMI classifications with precise body fat measurements using advanced DXA scans, researchers found that many people labeled as overweight or obese didn't actually have the corresponding body fat levels — while others were missed entirely. It's a stark reminder that a simple height-to-weight ratio is a pretty blunt tool for assessing health.

And if you needed another reason to keep a consistent sleep schedule: research from the University of Oulu found that large variations in bedtime could double the risk of cardiovascular disease. It's not just about how much sleep you get — it's about the consistency of when you get it. Your heart, apparently, likes routine.

Scientists also issued a serious warning this week about vaping. A sweeping review led by UNSW Sydney and published in the journal Carcinogenesis concludes that nicotine-based e-cigarettes likely pose a significant cancer risk — challenging the long-standing perception that vaping is a safer alternative to smoking. The evidence has been building for a while, and this review draws it all together in a pretty compelling case.

Let's zoom out to some planetary and evolutionary science, because there was no shortage of mind-bending discoveries this week.

A 500-million-year-old fossil is rewriting the origin story of spiders. During routine fossil cleaning, researchers discovered a tiny claw in a specimen where no claw should exist — and that small detail revealed a brand new species called Megachelicerax cousteaui. It's now the oldest known relative of spiders, pushing the origins of this entire group back by 20 million years. And it shows that key features of modern spiders and horseshoe crabs were already taking shape during the Cambrian Explosion.

Speaking of the Cambrian Explosion — scientists have also discovered fossils showing that complex animals existed millions of years before that iconic evolutionary event, at a newly identified fossil site in southwest China. The finds reveal a strange, diverse ecosystem where early versions of modern animals were already evolving. The timeline of complex life on Earth just got pushed back, again.

And there's more from the ancient world: wrinkled rock formations in Morocco known as elephant skin rocks suggest that microbes may have thrived deep in the dark ocean far earlier than expected — fueled not by sunlight, but by chemicals delivered by underwater landslides. It raises the possibility that we've been misinterpreting or overlooking similar fossils for years.

In a fascinating corner of paleontology, researchers found that ancient bees in a cave on Hispaniola were nesting inside fossilized bones, left behind by giant barn owls. The bees took advantage of the soft sediment and tiny cavities in fossilized jaws as ready-made nest sites, coating them with a smooth waterproof lining. Nature finds a way — even millions of years later.

Also this week, new research suggests that surviving burn injuries may have actually shaped human evolution. Repeated exposure to high-temperature burns throughout our history appears to have driven genetic adaptations that improve healing and infection response — though those same adaptations may worsen outcomes in severe trauma cases today. It's a striking example of how our ancient environment left marks on our biology.

And hominins in China were apparently far more advanced than we gave them credit for. An international team found evidence of sophisticated stone tool technologies in East Asia dating back 160,000 years — challenging previous assumptions about when and where complex innovation emerged in human prehistory.

On the climate front, two major findings caught our attention. First, old-growth boreal forests in Sweden are storing dramatically more carbon than managed forests that replace them — far more than scientists previously estimated. This has serious implications for how we think about forest management and climate strategy. Second, ancient Antarctic ice is now extending our climate record back three million years, offering new insight into how Earth's climate has evolved over deep time. Ice cores: nature's climate archive.

And Earth's magnetic field — which went through a period of wild, seemingly chaotic shifts about 600 million years ago — may not have been as random as it looked. A new study suggests those fluctuations may actually have followed a deeper global, organized pattern. Scientists are still piecing it together, but the planet's magnetic history just got a lot more interesting.

Now let's head to space, because NASA's Artemis II mission had quite a week. First, the crew received the official go-ahead for a critical engine burn that will send them on a path around the Moon — the first time humans will travel to lunar orbit since Apollo 17 in 1972. That is genuinely historic. But also — and we can't skip this — the crew had to deal with an unexpected toilet malfunction aboard the Orion spacecraft. They fixed it. They're back on track. But yes, even in the age of cutting-edge space exploration, plumbing remains a challenge.

And in the realm of future space exploration, a new concept proposes using SpaceX's Starship to cut travel time to Uranus nearly in half. By refueling in orbit and using the vehicle to help slow the spacecraft on arrival, a mission that would otherwise take over a decade to reach its destination could get there significantly faster. Uranus remains one of the most scientifically intriguing and least-visited planets in our solar system — and this could finally change that.

One more to round us out: scientists discovered that aging lung cells can trigger an exaggerated inflammatory response — creating clusters of immune cells that end up damaging lung tissue instead of protecting it. This helps explain why flu and COVID can become so much more dangerous for older adults. When they replicated this aging-related signal in young mice, their lungs behaved like older ones, leading to severe illness. Understanding this pathway could open new doors for treatment.

And finally — better french fries through science. Researchers found that combining regular frying with microwave heating reduces the amount of oil absorbed during cooking by using internal pressure to push oil out rather than letting it seep in. The result: faster, lower-fat fries that can still stay crispy. Sometimes science really does work for the people.

That is a wrap on today's episode of Peer Review'd. We covered deafness reversed by a single injection, ancient fossils rewriting evolutionary timelines, astronauts orbiting the Moon, and yes, healthier french fries. Science is relentless, and so are we. Thanks for listening — we'll see you next time.