On this episode of the podcast, and just in time for Easter, Professor Luke O'Neill is looking at the science of snacking.

What are the main reasons why we snack? Why do we like a crunchy snack? And what is 'food noise'?

There has been an outbreak of meningitis centred in Kent, in the UK, in recent weeks.

On this episode of Show Me The Science, Professor Luke O’Neill explains why this has happened, and what the two types of meningitis are...

This week, Professor Luke O’Neill dives into one of the most remarkable stories in modern medicine: the birth of Hugo, the first child in the UK to be born from a womb transplanted from a deceased donor. His mother, Grace Bell, born without a womb due to MRKH syndrome, calls her baby son “simply a miracle.”

Luke explores the incredible medical journey behind this milestone. The 10-hour womb transplant took place at The Churchill Hospital in Oxford in June 2024, followed by IVF treatment at The Lister Fertility Clinic in London. Consultant gynaecologist Professor Richard Smith, who has researched womb transplantation for over 25 years and was present at Hugo’s birth, was even honoured in Hugo’s full name.

Beyond the headline-grabbing story, Luke takes listeners through the broader science of organ transplantation. He explains how immunosuppressant drugs revolutionised transplant success, looks at cutting-edge frontiers like 3D-printed organs and the potential use of animal organs, and considers the ongoing challenge of organ shortages. He also touches on Ireland’s organ waiting list, especially for kidneys, and the recent updates to donor rules.

With St Patrick’s Day just around the corner, Professor Luke O’Neill takes a closer look at the man behind the legend—and the science behind the stories. Drawing on Patrick’s own Confessio, Luke explores how the saint lived a long life, likely thanks to a mix of lifestyle and genetics.

Could there have been two Patricks, Patricius and Palladius? Luke unpacks this theory and shares its surprising connection to the early days of Ireland’s Dublin Institute for Advanced Studies.

He also tackles the myth of Patrick banishing snakes, explaining how the last Ice Age shaped Ireland’s landscape and wildlife. And he examines the shamrock, used by Patrick to illustrate the Holy Trinity, and its medicinal properties, from easing menopausal symptoms and asthma to treating wounds and fevers.

It’s history, myth, and biology all rolled into one festive podcast.

Winter sports look clean and crystalline on the surface. Snow, ice, precision, courage. But scratch that frozen surface and you find molecular biology doing quiet, mischievous work.

In this week’s podcast, Professor Luke O'Neill takes us from the ski jump ramp to the veg aisle, via one of the strangest alleged performance hacks of the recent Winter Olympics.

First stop: hyaluronic acid. A substance your body already makes, found in skin and connective tissue, famous for its ability to hold vast amounts of water. That’s why it appears in skin creams, dermal fillers, and treatments for sore joints — it hydrates, cushions, and plumps.

Reports suggested some ski jumpers injected it weeks before competition to temporarily enlarge their genitals while being fitted for tightly regulated suits. If the swelling subsided by competition time, the slightly looser fabric could improve aerodynamics. In a sport decided by metres, even tiny changes in airflow can translate into significant gains. That raises an awkward question: if it enhances performance without acting like a traditional drug, does it still count as doping?

Then there’s broccoli. Many athletes were reportedly using concentrated broccoli juice supplements. Broccoli and other cruciferous vegetables contain isothiocyanates, compounds linked to anti-inflammatory effects. In high-impact, repetitive sports, reducing inflammation may aid recovery between events.

There’s early research exploring whether these molecules could help in conditions like ulcerative colitis and multiple sclerosis. But while broccoli is unquestionably nutritious, robust clinical evidence for performance-boosting concentrated extracts is limited. A single shot can equal several large heads of broccoli — and tastes predictably grim.

Winter sports may look like poetry in motion. Underneath, it’s chemistry in motion. And sometimes, it’s broccoli.

Cholesterol has a reputation problem. We tend to think of it as the enemy, but your body makes it for a reason. Every cell membrane relies on it, and it’s the building block for key hormones like oestrogen, progesterone, and corticosteroids. You also get cholesterol from your diet. The real issue isn’t cholesterol itself — it’s where it ends up.

In the early 1900s, pathologists examining people who died from heart attacks found arteries lined with cholesterol-rich plaques, complete with visible crystals. By the 1950s and 60s, research confirmed that high cholesterol in the blood is a major risk factor for heart disease. When plaques build up, they trigger inflammation and clotting, potentially cutting off blood supply to the heart.

Cholesterol doesn’t travel freely in the bloodstream — it’s packaged into tiny particles called lipoproteins. These act like delivery vehicles, carrying cholesterol around the body. Drugs such as statins reduce cholesterol production and improve its clearance, saving millions of lives. Exercise, diet, and blood pressure control are also critical, especially since high blood pressure and high cholesterol together significantly increase risk.

But there’s more to the story. Around one in 250 people have inherited conditions that leave them with very high cholesterol levels. And as listener Tara asked in her email to the podcast, what about Lipoprotein little a — or Lp(a)?

Lp(a) is a specialised lipoprotein that can increase inflammation and clot formation. Elevated levels are linked to a greater risk of heart attack — even if your standard cholesterol numbers look normal. That means measuring total cholesterol alone may not tell the full story.

On this week’s podcast Professor Luke O’Neill explores why cholesterol is essential, how it becomes dangerous, and why particles like Lp(a) could be key to identifying hidden heart risk.

Have a science question you’d like answered? Email laoneill@tcd.ie and it might feature in a future episode.

Why do we sweat? And what secrets does it hold about our bodies? On this week’s podcast, Professor Luke O'Neill dives into the fascinating science of sweat. From keeping our body temperature in check to signalling stress and even potential mate selection, sweat is far more than just water and salt.

The podcast explores how sweat is made by specialized eccrine glands, originating from plasma in our blood, and why humans are among the sweatiest animals on the planet. Luke explains how the average adult can produce up to four litres a day, and why staying hydrated is crucial.

But there’s more: stress, exercise, and climate all change how and why we sweat. Sweat itself is odorless, but bacteria, lactic acid, and urea can create the smells we associate with adolescence, gyms, and armpits. And surprisingly, sweat contains proteins that fight bacteria, hinting at a role in our body’s natural defence.

Could sweat one day be a diagnostic tool for disease? Why do identical twins sweat the same amount? And could it even act as a pheromone signal? Professor O’Neill explains all this and more, in a conversation sparked by a listener question from Siún.

If you want to ask Luke your own science question, email him at:

📧 laoneill@tcd.ie

Weather forecasts are famously imperfect, but the science behind them is far cleverer than we usually give it credit for.

In this week's podcast, Professor Luke O’Neill explores how weather forecasting works, and why floods remain one of the hardest things to predict. Luke isn’t a meteorologist — although he did briefly consider it in college — but too much physics put him off. Still, he’s an ideal guide to the basics because the weather is really about a few core ideas behaving badly.

At its heart, forecasting comes down to temperature, air pressure, humidity, sunlight, and the way air flows like a fluid. Air moves from high to low pressure, dragging wind and weather systems with it. Add water vapour into the mix and things get interesting very quickly.

People have been trying to predict the weather for hundreds of years, using almanacs, folklore, and observation. It was never perfect, but it mattered hugely to farmers and sailors. Rain, in particular, remains tricky. Moist air rises, cools and condenses into clouds — but rain doesn’t just appear. It needs tiny particles like dust, sea salt, or pollen to form droplets, and those microscopic details are hard to pin down.

Today’s forecasts rely on satellites, radar, weather balloons, and ground stations, all feeding data into powerful computer models. Those models keep improving, and artificial intelligence is now helping to sharpen predictions.

Flooding is even more complicated. It’s not just about how much rain falls, but how fast it falls, how long it lasts, and where it lands. Soil type, vegetation, evaporation, and urban concrete all matter. Forests and wetlands act like sponges, while cities can make flooding worse — something Ireland knows well after decades of building on flood plains.

Some countries lead the world in flood modelling, but nowhere reliably predicts flash floods. Luke argues that weather is a brilliant way to teach science, and that we already know how to reduce flood risk. The challenge now is acting on that knowledge and getting on with it.