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