Brain ageing starts in midlife – and your metabolism could be to blame

It’s easy to think of brain ageing as something that happens much later in life.

But research increasingly shows that changes in brain structure and function begin earlier than most people realise – often in your 40s.

Sure, many health problems become more common as we age (no news there), but changes to the brain – causing issues like memory loss and slower thinking – play a particularly big role in loss of independence and quality of life later on.

So, this really is worth thinking about sooner rather than later.

If you’ve found yourself feeling more forgetful, foggy or mentally drained lately, it might not just be down to stress or a busy schedule.

Your metabolism – the system that turns food into energy and helps keep your body in balance – could be playing a role.

Let’s explore the link between midlife metabolism and brain ageing.

When do our brains start to age?

Several recent studies suggest that brain ageing starts in midlife – often between the ages of 40 and 45. These include measurable changes in brain volume and connectivity, especially in areas related to memory, focus and decision making.

While this doesn’t mean everyone will experience noticeable cognitive decline at this age, it highlights the importance of protecting brain health early.

The metabolism–brain connection

Metabolism is not just about weight. It’s about how efficiently your body turns food into energy. Problems like insulin resistance, high blood sugars and inflammation affect every organ – including the brain.

In fact, some scientists now refer to Alzheimer’s as 'type 3 diabetes' because of the strong links between poor glucose control and cognitive decline.

That means the same habits that drive midlife weight gain and fatigue could also accelerate brain ageing.

What you can do in midlife

Midlife is when investing in your metabolic health pays off, not just for your waistline but also for your brain.

The good news is that small, consistent changes can make a big difference.

Strategies that take care of your metabolic health, and therefore are good for your brain, include:

• Eating a minimally processed, nutrient-dense diet

• Keeping blood sugars steady by balancing protein, fat and carbohydrates

• Prioritising regular physical activity, especially resistance training to maintain muscle

• Managing stress and getting enough restorative sleep

None of these are quick fixes; protecting your brain health is a long game, but the best time to start is now.

Summary

Brain ageing doesn’t wait for old age – it begins in midlife.

And your metabolism may be one of the most important levers you can pull to slow it down.

By taking action today, you’re investing in sharper thinking, better memory and greater independence tomorrow.

Ready to support your brain and metabolic health?

If stress, blood sugar swings or low energy are creeping into your life, you’re not alone – and you don’t need to navigate it on your own.

I work with men and women in midlife to optimise metabolic function, improve energy and support long-term brain health.

Get in touch if you’d like personalised guidance to help protect your brain, boost your energy and take charge of your health.

Contact me

Disclaimer

The information and advice I provided here is of a general nature and should never replace individual health or medical advice provided by your doctor or other healthcare professional involved in your care.