Dementia: Can you really prevent it?

Most of us know someone who has (or had) dementia. It’s not surprising, as in 2024 it became the leading cause of death in Australia, beating out ischaemic heart disease for the first time. 

It’s estimated that in 2026 there are 459,000 Australians living with dementia, with 2% of women and 1.3% of men affected. Let’s look at what dementia is, and whether you can do anything about it.

What is dementia? 

Dementia is not one condition; it’s a way to describe a collection of symptoms affecting the brain. In general, dementia is a change in how the brain functions that gets worse over time. Dementia can affect various aspects of daily functioning, including:

• Memory and thinking, like planning and problem solving

• Language and communication, such as difficulty finding words or expressing oneself

• Judgement of distances, directions or time

• Mood, socialisation, and behaviour

• Physical functioning, such as sleep, coordination, or food preferences

Although dementia can affect people of all ages, including children, it becomes more common as we get older. With more than 100 conditions capable of causing dementia, symptoms can look quite different from person to person.

Alzheimer’s disease is a specific type of dementia and is the most common cause, accounting for around 60% of cases. It occurs when abnormal proteins build up in the brain, damaging neurons and affecting how the brain functions over time.

There is currently no cure for dementia, although there are some treatments available that can slow down it’s progression for a while.

Is it possible to prevent dementia?

The short answer is yes, to some extent. Dementia isn’t an inevitable part of aging. Many people live their entire long lives without developing dementia symptoms. Around 45% of dementia risk is linked to factors that can be modified, potentially lowering the chances of developing dementia.

What are the risk factors for dementia?

Dementia risk is influenced by a combination of factors, including age, genetics, health and lifestyle. While some factors are outside our control, others are potentially modifiable, meaning there are steps we can take to reduce their impact on our risk.

Non-modifiable risk factors

Age is the strongest known risk factor for dementia, with risk increasing as we get older. Genetics and family history can also play a role, but having a relative with dementia doesn’t mean you’ll necessarily develop it. Most forms of dementia aren’t directly inherited, and rare inherited forms account for only a small proportion of cases.

Modifiable risk factors

Research has identified several potentially modifiable risk factors that may influence dementia risk throughout life. These include:

• Cardiovascular and metabolic health: high blood pressure, high LDL cholesterol, diabetes and obesity.
• Lifestyle factors: physical inactivity, poor nutrition, smoking and excessive alcohol consumption.
• Brain and sensory health: preventing head injuries, addressing hearing loss and getting vision problems assessed and treated.
• Mental and social wellbeing: depression and social isolation.
• Early-life and environmental factors: lower levels of education and air pollution.

While not every case of dementia can be prevented, addressing modifiable risk factors may help reduce or delay its onset. Let’s look at some of the ways that you can help to reduce your risk of dementia.

How can you reduce your risk?

There are changes you can make that can lower your chance of developing dementia and improve your health and wellbeing. Ideally, you want to work on reducing your risk decades before you would expect symptoms to show, but the best time to start is now.

1. Physical activity

Why it’s important

People who are more physically active have lower rates of Alzheimer disease, vascular dementia, and dementia of all causes than inactive people. 

What can you do?

The Department of Health, Disability and Aging recommends that all adults get 30 minutes of moderate to vigorous activity most days, such as walking, a sport, an exercise class, or a dance break. Also, muscle-strengthening activities like strength or resistance training, or heavy labour or lifting tasks two days a week.

Functional activities, exercises or activities that involve multiple joints and muscles working together, are suggested at least three times a week. This could be going up and down stairs, balancing exercises, yoga, pilates, qigong or similar activities. It’s also recommended that you keep moving, with several hours of light activity every day, just moving around and living your life, doing chores, playing an instrument, shopping, or stretching. 

Before you get overwhelmed by all of that, some activities can cover multiple requirements, such as a bout of gardening where you’re lifting heavy pots or digging holes is a functional and strength activity and getting your heart rate up! The most effective changes are those that you enjoy doing, so focus on activities you can maintain.

2. Improving dietary choices

Why it’s important

How nutrition affects your brain is complicated and difficult to measure. However, we do know some of the benefits of a balanced diet. Vascular disease, or how our blood flows to affect our brains and other organs, is a risk factor for dementia, as are diabetes and high blood pressure, all of which can be improved by our diet. Studies suggest that managing the risk in our middle years, during our 40s and 50s is more effective than trying to do it later. 

What can you do?

While no single nutrient or supplement acts as a silver bullet, many small choices add up over time. Current evidence suggests that a diet like the Mediterranean diet or variants like the Dash (Dietary Approaches to Stop Hypertension) or MIND (Mediterranean-DASH Diet Intervention for Neurodegenerative Delay), provides support for your brain health.

These diets are mostly plant-based, focusing on wholegrains like brown rice or whole wheat pasta and bread. They recommend dark green leafy vegetables as well as other vegetables. They also incorporate legumes and fruits, particularly berries. For fats, they focus on olive oil and nuts, as well as fatty fish like salmon, tuna, or sardines. 

It also limits fried foods, pastries and sweets, along with red meat, butter and cheese.

3. Get good sleep 

Why it’s important

There is growing scientific evidence that sleep is a factor in managing our brain function, which will come as no surprise to anyone who has tried to function after a poor night's sleep. The amount of sleep we get, and the quality of our sleep are linked to our risk of dementia. 

What can you do?

Adults should be aiming to get seven to nine hours of sleep at night. Prioritising sleep is important. The lifestyle changes to encourage better sleep are called sleep hygiene, and include: 

• Going to bed and getting up at the same time every day 
• Avoiding alcohol, caffeine, or large meals later in the day
• Getting exposure to natural daylight, particularly early in the day
• Reducing light and screen exposure before bed
• Creating a bedtime routine, something relaxing
• Fitting in regular physical exercise

If you experience daytime sleepiness, or ongoing difficulties getting enough or good quality sleep, consider seeing your GP. 

4. Quit smoking, and consider your alcohol consumption

Why it’s important

Smoking tobacco, including in your 40s and 50s, increases your risk of dementia by 30-50%. Excessive alcohol use also significantly increases your risk of dementia. In fact, alcohol-related dementia is one of the few types of dementia where, if diagnosed and managed early, the symptoms can be improved or reversed. 

What can you do?

It can be difficult to quit smoking, but many people have done so successfully. There are many sources of support. You can speak to your GP or pharmacist, and there is more information at Quit.org.au. 

There are no entirely safe levels of alcohol, however Australian guidelines recommend under ten standard drinks per week, and no more than four standard drinks on any one day. Some ways to decrease your drinking can be breaking up your drinks by having water, other non-alcoholic drinks between drinks, having food as well, and ordering smaller serves rather than larger ones, like pints.

Additional steps that can help lower your risk

• Support your mental health and social connection: Depression is linked with increased risk of dementia, so managing your mental health can positively affect your long-term risks as well as short term quality of life. Social connection is a protective factor, so make time for your friends and family, and making new connections.
• Protect your hearing and your head: Both hearing impairment and brain injuries are significant risk factors. Use protective equipment to save your hearing and your head, both at work and at play. 
• Keep your brain working: Being involved with games, reading, learning, and problem solving are protective factors. However, there really isn’t enough evidence yet that any specific ‘brain training’ is helpful, so do what interests you.

When to speak to a healthcare professional

If you’ve experienced any unexplained changes in your memory, thinking or mood, this is something to speak to your doctor about. 

The bottom line

Dementia is common, but it isn’t an inevitable part of aging. There are many risk factors you can address to lower your chances of developing dementia, even decades before symptoms might appear. Most of these factors have the added benefit of improving your current quality of life as well. While no strategy can guarantee prevention, healthy lifestyle choices can significantly reduce risk and support healthier ageing overall.

Related reads:

Is there a healthiest diet for seniors? | Healthylife

10 ways to bring more incidental exercise into your day | Healthylife

How to set and keep effective fitness goals | healthylife | Healthylife

How to get better sleep: 10 tips to a good night's rest | Healthylife

Social connection: Why it's important for our health | Healthylife

Reviewed by the Healthylife Advisory Board October 2026.