Something happens to your brain in your early 40s that no one tells you.
I’m approaching that milestone myself. And if you’re anything like me, you’re probably juggling work, relationships, and doing your best to stay healthy and grounded.
But how often do you stop and think about your brain's long-term health?
Because here’s the thing: a massive study involving over 19,000 brain scans just revealed that your early 40s might be a critical window for preventing age-related cognitive decline.
The researchers found that around age 40, the brain’s internal communication networks - the ones that keep you thinking clearly, feeling focused, and staying creative - start to destabilise.
And this decline doesn’t happen slowly. It accelerates through your 50s and 60s.
The Brain-Body Connection
So what’s causing this sudden brain shift? The researchers found the main culprit is metabolic dysfunction. Which essentially means the way your body uses energy.
Sign of metabolic dysfunction includes things like:
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Insulin resistance (your cells don’t process sugar properly)
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Chronic inflammation
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Vascular issues (poor blood flow)
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Excess fat and low muscle mass
When these things build up in midlife, they make it harder for your brain to get the energy it needs.
That’s when issues like brain fog, low mood, and memory problems can sneak in.
It doesn’t mean anything’s wrong with you. It’s just how the system your body ages. But now that we know this, we can act early.
And there are a number of ways you can improve your metabolic function at any age.
The Power of Ketones
The same study tested a solution. When people followed a ketogenic diet or used exogenous ketones, their brains stabilised.
Ketones are an alternative fuel your brain can use when carbs are low.
Unlike glucose, ketones don’t need insulin to enter brain cells. They slide in through a special “side door” (MCT transporters) and start powering your neurons, keeping brain networks strong and reducing wear and tear.
And guess who saw the biggest benefit in the study? People aged 40–59.
Whether you go full keto or experiment with ketone supplements, the research shows this could help you think clearer, feel better, and reduce your risk of future brain disease.
Other Metabolic Therapies
Ketones aren’t the only way to support your brain through metabolism.
If the idea of going full keto feels like a lot, there are plenty of other ways to boost your metabolic health and and protect your brain in the process.
These practices help reduce inflammation, improve insulin sensitivity, and support mitochondrial function.
And the best part? You might already be doing some of them.
Here are some of our favourite brain-friendly metabolic therapies:
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🧘 Breathwork & Meditation
Reduce stress, calm your nervous system, and lower inflammation. Deep breathing also improves oxygen delivery and blood sugar regulation. -
❄️ Cold Plunges
Cold exposure trains your mitochondria, improves insulin sensitivity, and boosts feel-good neurotransmitters like dopamine. -
🔥 Sauna
Mimics the effects of exercise, increases blood flow to the brain, and supports detox pathways. Regular sauna use is linked to lower risk of dementia. -
🌳 Nature Exposure
Time outdoors regulates circadian rhythms, supports parasympathetic nervous system activity, and lowers stress hormones that mess with metabolism. -
💤 Deep Sleep
Sleep is when your brain detoxes, repairs, and resets. Prioritising high-quality, uninterrupted deep sleep improves insulin sensitivity, lowers inflammation, and supports memory and focus. -
🏃♀️ Movement & Exercise
Whether it’s walking by the sea or strength training at home, consistent movement enhances glucose metabolism, brain-derived neurotrophic factor (BDNF), and mood. -
🍄 Functional Mushrooms
Mushies like lion’s mane, cordyceps, and reishi support cognition, energy, stress resilience, and even metabolic health. They work synergistically with the practices above to keep your brain resilient.
Together, these tools create a metabolic environment where your brain can thrive. The key is consistency and tuning into what makes you feel clear, strong, and inspired.
What This Means for You
Maybe you’re already health-conscious. Maybe you’ve tried meditation, cold dips, or whole foods.
Well, this is about building on that foundation, using metabolic therapies to support your most important tool: your mind.
This isn’t just about “avoiding Alzheimer’s.” It’s about showing up every day as your most energised, inspired self.
The kind who brings their whole creative genius to the table, and still has energy left for a truly enriching life.
Study: https://www.pnas.org/doi/10.1073/pnas.2416433122
