5 Things You Can Do In Midlife To Prevent Dementia

Did you know that dementia is now the leading cause of death in women in Australia? And that women are twice as likely to develop Alzheimer's disease as men?

The good news is that dementia is not inevitable. The science is clear: what you do in midlife matters enormously for your brain decades down the track. In fact, the brain changes that lead to dementia can begin 20 to 30 years before any symptoms appear, which means midlife is the most powerful window to act.

In episodes 307 and 308 of the Real Health and Weight Loss Podcast, Dr Mary and Dr Lucy break down exactly what drives dementia and what you can do about it. Here are five of the most important things you can start doing right now.

What is dementia?

Dementia is not a single disease. It's an umbrella term for a group of conditions that affect memory, thinking, behaviour, and the ability to carry out everyday tasks. More than 400,000 Australians are living with dementia right now, and that number is projected to reach almost one million by 2058.

There are several types, but these are the most common:

Alzheimer's disease is the most prevalent, accounting for around 70% of all dementia cases. It's characterised by the build-up of amyloid plaques and tau tangles in the brain, which progressively damage and destroy brain cells. One of the most striking things we now understand is that Alzheimer's is closely linked to insulin resistance in the brain, so much so that some researchers refer to it as "Type 3 Diabetes."

Vascular dementia is the second most common type. It occurs when blood flow to the brain is reduced or interrupted, often following strokes or as a result of long-term damage to blood vessels. High blood pressure, high blood sugar, and poor metabolic health are all significant risk factors.

Lewy body dementia involves abnormal protein deposits called Lewy bodies forming in the brain. It often causes changes in alertness, visual hallucinations, and movement problems similar to Parkinson's disease.

Frontotemporal dementia affects the frontal and temporal lobes of the brain, which control personality, behaviour, and language. It tends to appear at a younger age than other types, sometimes in people in their 40s and 50s.

While the types differ in their mechanisms, they share many of the same underlying risk factors: insulin resistance, chronic inflammation, poor sleep, chronic stress, and, for women, declining oestrogen. This is important because it means the same lifestyle changes that protect your metabolic health also protect your brain.

1. Improve your metabolic health

One of the most important, and most overlooked, connections in brain health is between insulin resistance and dementia. Alzheimer's disease is sometimes called "Type 3 Diabetes" because of how closely it is linked to insulin resistance in the brain.

When your cells stop responding properly to insulin, your brain is starved of the energy it needs to function. Over time, this drives inflammation, damages brain cells, and sets the stage for cognitive decline.

Where to start? Reducing ultra-processed foods and refined carbohydrates, prioritising real whole foods, and keeping your blood sugar stable are all steps that research supports. You don't need to count calories. You need to understand what's driving your insulin.

If you're not sure where to start, listen to Episode 307: How to prevent dementia where we break down the metabolic drivers of brain disease in plain language.

2. Prioritise sleep, non-negotiably

Sleep is when your brain does its housekeeping. During deep sleep, your brain's glymphatic system flushes out metabolic waste, including the amyloid plaques and tau tangles associated with Alzheimer's disease. When sleep is cut short or disrupted, that process is incomplete. Night after night, that adds up.

The research on this is striking. A landmark study published in Nature Communications (2021) found that people in their 50s and 60s who slept six hours or less per night were 30% more likely to be diagnosed with dementia later in life compared to those getting seven hours. A Monash University-led study published in Neurology (2023) found that people with the most irregular sleep patterns were 53% more likely to develop dementia over a 7-year follow-up period, with researchers pointing to circadian disruption as a likely driver of metabolic dysfunction and vascular brain damage. And a 2025 study in Neurology found that chronic insomnia was associated with a 40% higher risk of dementia or mild cognitive impairment, with sleep disruption appearing to accelerate brain ageing by three to four years.

We’ll saay it louder for the people up the back! Three to four years of accelerated brain ageing from poor sleep. That is not a small effect.

The good news is that sleep is something you can work on. Aim for seven to nine hours per night. Go to bed at a consistent time. Reduce alcohol, late-night screens, and high-stress evenings where you can. Going to bed on time is one of the most evidence-backed, completely free things you can do for your brain, and it didn't even make the ABC's list this week.

3. Move your body, especially after meals

Exercise is one of the most well-researched ways to reduce dementia risk. It increases blood flow to the brain, reduces inflammation, improves insulin sensitivity, and supports the growth of new brain cells.

Here's something most people don't know: even ten minutes of movement after a meal can significantly lower your post-meal blood sugar spike. This matters because repeated blood sugar spikes over years and decades contribute to the very insulin resistance that can affect your brain.

You don't need to run marathons. A short walk after dinner, some resistance training a few times a week, and moving more throughout the day all add up to meaningful protection over time.

4. Manage stress. Your brain is listening.

Chronic stress is a significant driver of insulin resistance and brain inflammation. When your stress response is constantly activated, cortisol remains elevated, and over time, research suggests this can affect the hippocampus, the part of your brain central to memory and learning.

Stress management isn't a luxury. It's a brain health strategy. Practical approaches include mindfulness, breathwork, time in nature, and building social connections. Even a few minutes of deliberate calm each day can shift your nervous system in the right direction.

5. Consider the role of oestrogen

This one is specifically for women in perimenopause and menopause, and it's worth knowing about.

Oestrogen is not just a reproductive hormone. It's deeply neuroprotective. It supports blood flow to the brain, reduces inflammation, and helps regulate the metabolic processes that research suggests are protective against Alzheimer's disease. The significant drop in oestrogen during menopause is thought to be one of the key reasons women are at higher risk.

For decades, women and doctors were scared off hormone therapy by the flawed 2003 WHI study. But the latest evidence tells a very different story: for many women, menopausal hormone therapy (MHT) initiated in the right window may help reduce dementia risk.

If MHT isn't right for you, the other strategies in this list still powerfully support brain health. This is a conversation worth having with your doctor, and we break it all down in Episode 308: Can HRT prevent dementia?

The bottom line

Dementia is not just bad luck. It has clear drivers, and many of them are things you have real influence over, starting right now.

Your metabolic health, your sleep, your movement, your stress levels, and for women, your hormones, are all levers you can pull. The earlier you start, the more protection you build.

Listen to episodes 307 and 308 of the Real Health and Weight Loss Podcast wherever you get your podcasts, or head to rlmedicine.com/podcast.

About us

We are Dr Mary Barson and Dr Lucy Burns, the founders of Real Life Medicine. We help women who have been on every diet under the sun optimise their health without feeling miserable or deprived.

We do this with our three-step framework:

• Strategies to improve your metabolism
• Brain-based skills to overcome self-sabotage
• Tools to make it easy to implement

With this comes increased energy, vitality, and confidence. At Real Life Medicine, we believe in the power of small steps. You don't have to do all the steps at once.

We go further into this in My Metabolic Action Plan (MyMAP).

This step-by-step programme is the map to improved metabolic health that not only supports weight loss and increases your energy levels and mood, but also helps reduce the risk of chronic disease in the future.

Find out more about My Metabolic Action Plan

This content is for general information purposes only and does not constitute medical advice. Please speak with your healthcare provider before making changes to your health care.