The Active Site

Microplastics have been detected in human brain tissue, and in 2025 one study produced a number that spread around the world: roughly a spoonful of plastic in the brain. But the closer you look at how that number was produced, the stranger the story becomes. This investigation follows the evidence to find out what is actually accumulating in our brains, how much is there, and whether it is doing harm.

Time Stamps

0:00 – The spo...

BPC-157 is now used as a recovery peptide for tendon injuries, muscle strains, and stubborn joint problems. Some people report remarkable results, while others feel nothing. But its story did not begin in sports medicine. It traces back through human stomach fluid, an old Yugoslav research program, pharmaceutical development, and decades of experiments that still leave major parts of the peptide’s history unresolved. This inv...

There is an element sitting in your brain right now, and nobody has established how much you are supposed to have.  It may shape how you think, how you act, and whether your mind holds up as you age. Last year a Harvard lab placed it near the center of Alzheimer's, arguing that running short of it may be one of the first things that goes wrong in the diease. It is already sold as the next longevity compound, the thing that fin...

Creatine is one of the most-studied supplements in the world, taken by millions of people who have been told for years it is about as safe as anything on the shelf. Then, within weeks of each other, two peer-reviewed studies reached opposite conclusions about what it does to cancer. One found that creatine helped cancer spread faster through the body. The other found that creatine helped the body fight cancer off. Same molecule, se...

There are tests now that claim to measure how old you really are. Not the number on your birth certificate, but your biological age, the idea being that two people born on the same day can be aging at different speeds, and that a blood or saliva sample can tell them apart. It starts with a discovery from fifteen years ago, that chemical marks on your DNA shift as you get older. Since then, the clocks built on it have moved fast, fr...

For decades the reassuring story about tattoos was that the ink stays put: a permanent mark, sealed in the skin, chemically done with your body. It isn't. Pigment migrates out of the skin and lodges in your lymph nodes, carrying the carcinogens it came with, and it stays there for the rest of your life. That's not in dispute. What is in dispute is whether any of it actually causes cancer, and in 2024 and 2025 several teams finally ...

For most of a decade, vitamin D came with a warning: take it on its own, and the calcium it raises ends up in your arteries instead of your bones. The fix, supposedly, is vitamin K2. The claim is unusually specific for supplement advice, specific enough to put to randomized, placebo-controlled trials with arterial calcium scored on CT before and after. The trials came back. They don't agree with each other. So what does the evidenc...

For most of the last century, apigenin was a footnote — a yellow pigment in chamomile and parsley, studied mostly by people cataloguing the antioxidants in plants. In the last few years it has become one of the most-recommended compounds on the internet: the third ingredient in the famous sleep stack, a fixture in longevity protocols built around NAD+, and an addition to formulas aimed at cellular aging itself. But how do...

For decades, magnesium sat in the supplement aisle as a mineral for muscle cramps, sleep, and general nutrition. Around 2010, that changed. A branded form called magnesium L-threonate launched on the back of a 2010 MIT rodent paper, and a new category was born — magnesium for the brain. Fifteen years later, that category has expanded to include other brand-targeted forms, premium price points, and confident claims about cogni...

For thirty years, the supplement aisle has sold fish oil as one of the simplest decisions you can make for your brain. In 2026, two research teams on opposite sides of the world published papers that complicate that story, and the literature behind them has been building for almost twenty years.

IN THIS INVESTIGATION

• What a 2026 ADNI cohort study of 800+ older adults actually found
• Why faster cognitive decline in fish oil users sh...

PREFACE: This is an explanation of the debate the guidelines have stimulated. It references the data used to rationalize the guidelines and the data used to oppose them. There is nothing here that was not cited by the new or old guidelines. For a full review, please see my website.

The 2025–2030 Dietary Guidelines introduced changes that have caused confusion, disagreement, and strong reactions across nutrition and public heal...

Omega-3 supplements are at the center of a controversy regarding their oxidation levels and potential harm. This presentation addresses the gap between claims of harm and the available human data, explaining how oxidation is measured and interpreted. 

00:00 Introduction to Omega-3 Supplements

00:49 Understanding Oxidation in Fish Oil

01:10 Measuring Oxidation: Peroxide, Anisidine, and Totox Values

01:50 The Flavoring Problem in Ox...

Nutrients are usually studied in isolation, yet synapses don’t operate that way. This episode examines research showing that coordinated nutritional inputs can reshape synaptic proteins and neural firing patterns (effects that isolated inputs fail to produce). The shift isn’t about stronger signaling, but more organized signaling within brain circuits.

The goal: explain why biological systems respond to combinations rath...

L-arginine is usually treated as a simple nitric-oxide precursor, a molecule with a narrow vascular role. But across multiple lines of research, it keeps appearing in places it shouldn’t: improving cerebral blood flow in older adults, shifting cognitive performance, and, most unexpectedly, altering how amyloid-β proteins aggregate in the brain. This episode unpacks why these effects are so unusual, and how they connect to the...

Parkinson’s is often framed as a brain-first disorder, but some of its earliest changes unfold in the gut. This episode unpacks a global metagenomic analysis showing that two surprisingly ordinary microbial compounds, ones most people consume every day, quietly disappear in Parkinson’s. When these pathways vanish, gut defenses weaken, protective metabolites fall, and enteric neurons may become vulnerable to the toxins t...

A new brain-imaging meta-analysis has uncovered the first consistent biochemical signature across multiple anxiety disorders (a shift in a single molecule that moves in the opposite direction of every major psychiatric condition studied to date). Even more surprising, a separate study in young adults under metabolic strain reveals a nearly identical pattern emerging outside the brain. In this episode, we trace the science behind th...

Magnesium salts are often marketed as if they target specific tissues - i.e., “threonate for the brain,” “glycinate for calm,” “taurate for the heart.” Part 2 breaks down what the evidence actually shows: animal studies demonstrating tissue differences that have never been replicated in humans, cognitive and sleep trials where multiple forms show benefit, and meta-analytic data indicating what re...

Magnesium supplements are marketed like different compounds with different biological targets - i.e., “for sleep,” “for the brain,” “for stress,” “for energy.” But the foundation of these claims depends on chemistry: how magnesium salts dissolve, how they release Mg²⁺ in the gut, and how much actually reaches circulation.

Part 1 breaks down the first half of the magnesium story: why ma...

A medication used by millions (including off-label usage for “longevity” purposes) may alter the fundamental pathways responsible for exercise adaptation. This episode reviews new 2025 data showing reduced improvements in vascular insulin sensitivity, aerobic capacity, and glucose regulation when the medication is paired with structured training. We look at prior evidence of blunted mitochondrial respiration and diminis...