The One Olive Oil Swap That Could Protect Your Brain As You Age
What if the olive oil in your pantry is actually working against your brain?
If you've been drizzling olive oil on everything, such as salads, roasted veggies, and bread, you're probably feeling pretty good about your choices. Olive oil is healthy, right? Well, yes. But new research1 suggests it's a bit more complicated than that.
A study published in the journal Microbiome found that the type of olive oil you consume may significantly impact your cognitive function over time. And here's the twist: while virgin olive oil was linked to improved brain health, common (refined) olive oil was actually associated with cognitive decline. The difference? It may come down to your gut.
What the study found
Researchers analyzed 656 participants aged 55 to 75 with overweight or obesity and metabolic syndrome (a population at high risk for cognitive decline). They tracked olive oil consumption and measured cognitive performance at baseline and after a two-year follow-up.
The key distinction: virgin olive oil (VOO) versus common olive oil (COO), which is more refined and lower in bioactive compounds.
The findings were striking:
- Higher intake of virgin olive oil was associated with improved cognitive function over the two-year study period.
- Higher consumption of common olive oil was linked to lower gut microbiota diversity and accelerated cognitive decline.
This wasn't a subtle difference. The type of olive oil people reached for appeared to push their brain health in opposite directions.
Perhaps most intriguingly, the researchers found that gut microbiota (specifically a bacterium called Adlercreutzia) may serve as a mediator in the relationship between virgin olive oil consumption and positive changes in cognitive function. In other words, the beneficial effects of virgin olive oil on the brain appear to work, at least in part, through changes in gut bacteria.
Why virgin olive oil works differently
So why does virgin olive oil protect your brain while refined olive oil may not? It comes down to polyphenols.
Virgin olive oil retains the bioactive compounds naturally present in olives—including polyphenols like hydroxytyrosol and oleuropein, which are powerful antioxidants with anti-inflammatory properties. When olive oil is refined (processed to remove impurities and extend shelf life), most of these beneficial compounds are stripped away. What you're left with is a neutral-tasting oil that shares a similar fat profile but is missing the good stuff.
Those polyphenols in virgin olive oil don't just float around doing nothing. They serve as fuel for beneficial gut bacteria. And your gut microbiome has a direct line to your brain.
This connection is called the gut-brain axis: a bidirectional communication system between your gut and your central nervous system. What you feed your gut bacteria influences the signals they send to your brain through immunological, neuronal, and metabolic pathways.
Think of it this way: virgin olive oil is like premium fuel that your gut bacteria can actually use. Refined olive oil? It's more like empty calories for your microbiome, and it doesn't give them much to work with.
The study confirmed this mechanism: participants who consumed more virgin olive oil had greater gut microbiota diversity overall, while those consuming more common olive oil had lower alpha diversity of their microbial communities.
How to choose the right olive oil
Ready for the practical part? Here's how to make sure you're getting the brain-boosting benefits:
- Look for the right label. You want "extra virgin" or "virgin" olive oil. If the label says "pure," "light," or just "olive oil," it's refined and missing most of those polyphenols.
- Check for a harvest date. Unlike wine, olive oil doesn't get better with age. Look for bottles with a harvest date and try to use it within 12-18 months of that date.
- Store it properly. Keep your olive oil in a dark bottle (or a dark cabinet), away from heat and light. These degrade the polyphenols over time.
- Don't be fooled by price alone. Expensive doesn't always mean better. Look for certifications like the California Olive Oil Council seal or PDO (Protected Designation of Origin) labels from Europe.
- Use it generously. The study participants who saw benefits were consuming virgin olive oil regularly as their primary fat source. Drizzle it on salads, use it for low-to-medium heat cooking, and finish dishes with a good pour.
The bottom line
The type of olive oil you choose may matter as much as using olive oil at all. According to this study, virgin olive oil (with its polyphenols intact) appears to support cognitive function by feeding the beneficial bacteria in your gut. Refined olive oil, on the other hand, may not offer the same protection, and could even work against you.
This is one of the easiest swaps you can make. You don't need to overhaul your entire diet. Just upgrade your olive oil. Your gut (and your brain) will thank you.