Microplastics Might Be Messing With Your Brain

Sometimes I can kinda get a little health nutty. I’m trying not to be all Bryan Johnson but sometimes I can latch on to things. I try to be scientific about things but, as many, I have a growing concern for microplastics and PFAS. Not only do non degradable plastics have a cost for the environment. They probably do for our health as well. And so I thought I’d touch on this in this week’s Neurosurgeon’s Guide Newsletter.

In This Edition

1. Brain Health News

2. Brain Hack of the Week

3. Reflections from the OR

4. The HPA-Axis

5. Final Thoughts

Microplastics Found in Human Brain: A Hidden Health Crisis 🧠

New research shows tiny plastic particles are building up in our brains at alarming rates, with possible links to diseases like Alzheimer's.

Scientists have found something scary in our brains - tiny bits of plastic. These microplastics (pieces smaller than 5mm) aren't just floating in our oceans or food - they're actually getting into our bodies and staying there. And what's really worrying is how much of it is in our brains.

A 2024 study found that brain samples contained about 0.5% plastic by weight. That might not sound like much, but it's actually 10 to 20 times more than what's found in other organs like the liver and kidneys. Even more concerning? People with dementia had up to ten times more plastic in their brains than those without the condition.

The numbers keep going up too. Between 2016 and 2024, the amount of microplastics found in brain tissue jumped by about 50%. These aren't just harmless specks - they can mess with how our cells work, cause inflammation, and might lead to heart problems and other health issues.

Think your body's natural defenses will keep you safe? Think again. These tiny plastic particles are sneaky - they're getting past the blood-brain barrier, which is supposed to protect our brains from harmful stuff. They're not just in our brains either - scientists have found them in bone marrow, reproductive organs, and even in unborn babies through the placenta.

Animal studies paint an even grimmer picture, showing these plastics might cause fertility problems and certain types of cancer. The scary part is that we're still learning about all the ways these particles might be hurting us.

What's clear is that plastic pollution isn't just an environmental problem anymore - it's become a health crisis that's literally getting inside our heads. We need to act fast to understand exactly what these plastics are doing to our bodies and figure out how to protect ourselves.

TLDR:

• Microplastics found in human brains at levels 10-20 times higher than other organs

• Brain samples contain about 0.5% plastic by weight

• People with dementia show up to 10x more plastic in their brains

• Microplastic levels in brain tissue increased 50% from 2016 to 2024

• Particles found throughout the body, including bone marrow and reproductive organs

• May cause inflammation, cell damage, and various health problems

• More research needed to understand long-term health effects

Brain Hack of the Week: The 90-Second Cold Rinse Reset

What it is:
A rapid cold exposure technique that boosts mental clarity, lowers inflammation, and sharpens executive function — all in under 2 minutes.

How to do it:

1. End your shower with 90 seconds of cold water (as cold as tolerable).

2. Breathe deeply — 4 seconds in, 6 seconds out — to avoid the gasp reflex.

3. Focus on relaxing your shoulders and jaw to minimize tension.

Why it works:
Cold exposure activates the locus coeruleus, a brainstem nucleus that floods your brain with norepinephrine, enhancing attention, alertness, and mood. It also reduces neuroinflammation and trains your body to better regulate stress.

When to use it:

• First thing in the morning to replace coffee

• Before cognitively demanding tasks

• Midday slump (especially if you’ve been sitting for hours)

Scientific roots:
Research shows that brief cold exposure increases dopamine levels by up to 250%, improves working memory, and enhances stress resilience via the hypothalamic-pituitary-adrenal (HPA) axis reset.

Reflections from the OR

I hate being sick. But I also hate working not to be. Sickness and death are inevitabilities, it is true. And I see plenty of people who make healthy choices and still get terrible diseases. But there is no doubt that your choices can improve your chance of living healthier and potentially happier.

Some of these are simple - don’t smoke, take your statin, walk. Some of them are harder - cut down on ice cream 😀 

Or take a cold plunge.

Or cut out plastics.

I don’t fault anyone for their choices for themselves. I won’t get into the nuance of social costs of public health. In general who am I to be upset at a reasonable adult for driving without a seatbelt or eating a ton of processed foods? In the end, to each their own in some ways.

But I can certainly offer advice for healthier choices and I do think that while optimizing for health all the time, at all moments can rob us opportunities and humanities that in general living healthier gives you a longer function span and health span and give you more time for happiness and a life you enjoy.

And so I try to live a little bit healthier every week. Small changes can add up. I don’t need to be Bryan Johnson. I don’t need to judge myself when I fall short of those changes - say having some extra cookies. I just need to try to do better next time.

The HPA Axis – Your Brain’s Stress Thermostat

What it is:
The Hypothalamic-Pituitary-Adrenal (HPA) axis is your brain-body communication highway for managing stress. It connects the hypothalamus (brain command center), pituitary gland (master hormone regulator), and adrenal glands(cortisol producers).

How It Works (In Seconds):

1. A stressor (real or perceived) is detected by your brain.

2. The hypothalamus sends CRH (corticotropin-releasing hormone) to the pituitary.

3. The pituitary releases ACTH (adrenocorticotropic hormone), signaling the adrenals.

4. The adrenals pump out cortisol — your body’s main stress hormone.

Why It Matters for Cognitive Health:

• Short bursts of cortisol improve memory encoding and focus.

• Chronic activation of the HPA axis leads to hippocampal shrinkage, impaired memory, and executive dysfunction — a key driver of brain fog and cognitive fatigue.

• Over time, your brain becomes less sensitive to cortisol, causing dysregulation of mood, sleep, and energy.

Optimization Tip:

Daily practices like deep diaphragmatic breathing, cold exposure, morning sunlight, and adaptogens (e.g., ashwagandha, rhodiola) help reset HPA axis tone, reducing baseline cortisol and sharpening cognitive performance.

Final Thoughts

Be healthy a little bit more every week. Take what is valuable for your health and your brain fitness and try to adopt it. Don’t judge if you fall short of the practice, just try again. And those things that seem kooky or too much? Throw them aside.

Stay sharp,

Colin