Extra Virgin Olive Oil and Brain Health: How EVOO Protects Cognitive Function After 40

I've just come across some research from 2026 that's properly brilliant, and it's changed how I think about something I've been using wrong my entire life. Extra virgin olive oil. Not the cheap stuff you grab from the supermarket shelf without thinking. The good stuff. The liquid gold that actually costs what it's worth.

Turns out, the oil you drizzle on your salad isn't just making your rocket leaves taste better. It's feeding your gut bacteria, and those bad boys are running the show when it comes to keeping your brain sharp as you age.

Your Gut Is Running Your Brain (And Most People Don't Know It)

Right, let me paint you a picture. You've got trillions of bacteria living in your gut. Proper trillions. And they're not just sitting there having a laugh. They're producing chemicals, sending signals, and basically deciding whether your brain stays firing on all cylinders or starts sputtering like a knackered engine.

Recent research has shown that virgin olive oil, specifically the extra virgin stuff, protects cognitive function through the gut microbiota. People consuming EVOO showed greater microbial diversity and improved cognitive function. But here's where it gets mental. Those who consumed refined olive oil? Less diverse microbiota over time. The difference is stark.

The science points to a specific bacterial genus called Adlercreutzia. These microscopic legends appear to be linked directly to the cognitive benefits you get from quality olive oil. Feed them the good stuff, and they help keep your brain healthy. Feed them refined dish water, and you're basically starving the team that's supposed to keep you sharp.

This isn't some woo-woo nonsense. We're talking about measurable improvements in blood-brain barrier function, the thing that protects your grey matter from all the crap floating around in your bloodstream. When that barrier breaks down, you're looking at early signs of Alzheimer's and dementia. And nobody wants that.

The Super Unleaded vs Cheap Crap Analogy

You know when you put cheap fuel in a performance car? It runs. But it doesn't run properly. It's sluggish, it misfires, and over time, you're doing damage you can't see until it's too late.

Your brain is that performance car. Extra virgin olive oil is super unleaded. Refined olive oil? That's the cheap crap you regret using six months down the line when things start going wrong.

The difference between EVOO and refined oil comes down to biophenols. These are bioactive compounds that get stripped out during the refinement process. Multiple studies show that while both types of olive oil improved cognitive ratings, only EVOO enhanced blood-brain barrier function and reduced permeability. That's huge.

EVOO contains up to 83% monounsaturated fatty acids by weight, plus polyphenols with antioxidant activity. These components work through multiple mechanisms, promoting neurogenesis (fancy word for growing new brain cells), reducing Alzheimer's biomarkers like amyloid-beta and tau phosphorylation, and enhancing functional connectivity between brain regions.

In plain English? The good stuff helps your brain grow new connections, sweep out the rubbish, and stay connected.

The Numbers Don't Lie (And Neither Does Your Microbiome)

Here's something that'll make you pay attention. People consuming at least 7 grams of olive oil daily, that's roughly half a tablespoon, showed a 28% lower risk of dementia-related death compared to non-consumers. Let that sink in for a second. Half a tablespoon. That's nothing.

But it has to be the right oil. The research is clear. In individuals with mild cognitive impairment, daily EVOO consumption improved clinical dementia ratings and behavioural scores while enhancing blood-brain barrier function. These are clinical measures, not someone's opinion about feeling a bit sharper after lunch.

The gut connection is what fascinates me most. We've been banging on about gut health and microbiome diversity for years at Functional Drinks Club, but this research ties it directly to cognitive function in a way that's impossible to ignore.

Your gut bacteria produce short-chain fatty acids (SCFAs) when they ferment the right fibres and fats. These SCFAs are chemical messengers that influence everything from inflammation to brain function. When you feed your microbiome quality fats like those found in EVOO, you're essentially giving your gut bacteria the tools they need to send "keep this brain healthy" signals.

Improving Gut Health Isn't Just About Kombucha (But That Helps Too)

Right, I know what you're thinking. "Kev, you sell fermented drinks. Of course you're going to link this back to gut health." Fair point. But hear me out.

The quality over quantity principle applies to everything you put in your body. Whether it's the oil you cook with, the kombucha you drink, or the beer you choose when you're off the sauce. It all matters.

We know that gut bacteria control food cravings. We know that diversity in your microbiome is linked to better health outcomes across the board. And now we know that the type of olive oil you use can directly influence how well your brain ages.

The Mediterranean diet, which is heavy on EVOO, consistently shows associations with preserved cognitive function and reduced dementia risk. The MIND diet, a hybrid of Mediterranean and DASH diets, does the same. But here's the thing, it's not just the diet as a whole. It's the individual components doing their job.

Quality fermented drinks like kombucha, quality fats like extra virgin olive oil, quality sleep, quality movement. These aren't luxuries for people with too much time on their hands. They're the basics of being fit after 40 and not turning into a confused mess by the time you hit 60.

What This Means For You (The Actionable Bit)

Stop buying cheap olive oil. I'm serious. That bottle for £3.99 at the supermarket? Bin it. It's doing nothing for you except adding empty calories.

Invest in proper extra virgin olive oil. Cold-pressed, ideally from a single source, in a dark bottle. Yes, it's more expensive. Yes, it's worth it. This is your brain we're talking about, not a Sunday roast.

Use at least half a tablespoon daily. Drizzle it on salads, dip your bread in it, use it to finish cooked dishes. Don't cook with it at high heat (you'll destroy the polyphenols), but use it liberally everywhere else.

Combine it with other gut-friendly habits. Fermented foods, prebiotic fibres, quality movement. Your microbiome needs variety to thrive, and improving gut health isn't a one-trick show.

Support independent makers. This goes for olive oil, functional drinks, everything. The big corporations aren't incentivised to sell you quality. They're incentivised to sell you volume at the lowest possible cost. That means refinement, processing, and stripping out the very compounds that make food functional.

When you buy from independent producers who give a damn about their craft, you're not just getting better products. You're supporting a system that values quality over quarterly profits. And that matters more than most people realise.

The Bottom Line

At 46, I'm done pretending that quick fixes and cheap shortcuts are going to cut it. Your brain is the most complex machine you'll ever own, and it deserves better than bargain bin fuel.

The research is clear. Extra virgin olive oil protects cognitive function through your gut microbiota. It enhances blood-brain barrier function. It reduces dementia risk. And all it takes is half a tablespoon of the good stuff daily.

This isn't about living forever or trying to stay 25 until you're 70. It's about staying sharp, staying functional, and being able to remember why you walked into that room when you're 65. That's not too much to ask.

So go buy some proper olive oil. Pour it generously. Feed your gut bacteria the quality fuel they deserve. And maybe, just maybe, grab some quality kombucha while you're at it. Your future self will thank you.

Trust me, your brain's worth more than the price difference between cheap and quality. And if you're not willing to invest in that now, you'll pay for it later when it actually matters.

You can buy some of the good stuff right here from our shop.