Introduction
Dementia is not a single disease. It is a broad term for a group of conditions that affect memory, thinking, and the ability to carry out daily tasks. In Australia, dementia is now the leading cause of death overall, and has been the leading cause of death among Australian women since 2016. According to Dementia Australia, an estimated 446,500 Australians are currently living with dementia (Dementia Australia, 2026), and that number is expected to grow significantly as our population ages.
What many people do not realise is that dementia is not simply the result of getting older. Research increasingly points to lifestyle factors, many of them modifiable, as key contributors to cognitive decline. That means the way we live, the habits we carry for decades, can either protect the brain or gradually place it under strain.
This is about awareness. It is about giving families, carers, and older Australians the clearest possible picture of what the research shows, so that real conversations and real changes become possible.
At Fleet Healthcare, I have and our team have worked with hundreds of older Australians in their homes. I have seen how isolation, inactivity, poor sleep, and unmanaged health conditions quietly take a toll over time. I have also seen what happens when someone gets the right support early. The difference is real, and it matters.
So let us look at what the evidence actually says about the habits most commonly linked to dementia, and what you can do about it now.
Table of Contents
- Sedentary Lifestyle and Lack of Physical Activity
- Poor Sleep Patterns and Chronic Fatigue
- Social Isolation and Lack of Mental Stimulation
- High Sugar and Ultra Processed Diets
- Smoking and Excessive Alcohol Consumption
- Untreated Hearing Loss and Cognitive Strain
- Chronic Stress, Anxiety and Depression
- What the Research Says About Prevention
- When to Speak to a Health Professional
- Frequently Asked Questions
- Final Thoughts and Call to Action
Key Takeaways
- A sedentary lifestyle, poor sleep, social isolation, and an unhealthy diet are all linked to an increased risk of dementia in older Australians.
- Untreated hearing loss is a significant and often overlooked risk factor for cognitive decline.
- Smoking and excessive alcohol consumption damage the brain and vascular system over time, increasing dementia risk.
- Chronic stress, anxiety, and depression are not just emotional concerns. They can have lasting effects on brain structure and function.
- Many dementia risk factors are modifiable, meaning that changes made at any age, even later in life, can make a meaningful difference.
- Early intervention and access to the right allied health supports, including physiotherapy and occupational therapy, can help protect cognitive and physical function.
Sedentary Lifestyle and Lack of Physical Activity
One of the most consistent findings in the research on brain health is this: regular physical movement protects the brain. And the flipside is equally clear. A sedentary lifestyle is one of the habits most strongly associated with an increased risk of dementia.
When I visit clients at home, I often see how limited movement has become part of daily life without anyone intending it to be. A person who used to walk to the shops now sits for most of the day. Someone who once gardened regularly has stopped because their knees hurt. The activity gradually disappears, and with it goes one of the brain’s most important forms of protection.
Physical activity supports brain health in several ways. It increases blood flow to the brain, supports the growth of new nerve connections, reduces inflammation, and helps regulate blood pressure and blood sugar, both of which are independently linked to dementia risk. Exercise also supports mood, sleep quality, and social engagement, all of which have their own effects on cognitive function.
You do not need to run marathons. Walking, swimming, gentle strength work, and even supervised physiotherapy exercises at home can all contribute meaningfully to brain health. The key is consistency and finding movement that is realistic for someone’s life and ability.
This is exactly where mobile physiotherapy makes a real difference. Not everyone can get to a gym or a clinic. But we can bring structured, safe, supervised movement directly into the home. We meet people where they are, and we build activity into the life they actually live.
Healthdirect Australia notes that regular physical activity is one of the most effective steps a person can take to reduce their risk of dementia. You can read more at Visit Healthdirect
Poor Sleep Patterns and Chronic Fatigue
Can poor sleep lead to memory loss? Based on what we know now, the answer appears to be yes, particularly when poor sleep becomes a chronic pattern over years.
Sleep is not a passive state. During deep sleep, the brain undergoes a kind of biological maintenance. It consolidates memories, clears out metabolic waste products, and repairs neural pathways. One of the proteins that accumulates during wakefulness and is cleared during sleep is amyloid beta, which is associated with Alzheimer’s disease when it builds up in the brain.
People who consistently sleep fewer than six hours a night, experience fragmented sleep, or suffer from untreated sleep disorders such as sleep apnoea may be at higher risk of cognitive decline over time. This is not about the occasional bad night. It is about patterns that persist for months and years.
In older Australians, poor sleep is often dismissed as simply part of ageing. It is not. There are real and treatable causes. Pain, anxiety, depression, medication effects, and sleep apnoea are all common contributors. When these are identified and addressed, sleep can improve, and with it, cognitive function.
I have seen this play out clinically. Clients who begin to sleep better often report sharper memory, better mood, and more energy. These are not small improvements. They change quality of life.
If someone you care for is struggling with sleep, that is worth raising with their GP. It is also worth considering whether pain or mobility issues are affecting their ability to get comfortable or move safely at night. That is an area where a physiotherapist working in the home can genuinely help.
Social Isolation and Lack of Mental Stimulation
This is one that I feel strongly about. Social isolation is not just a quality of life issue. It is a brain health issue.
When we interact with others, when we problem solve, have conversations, laugh, argue, and share experiences, we are exercising the brain. Social engagement keeps neural networks active, challenges our thinking, and provides the kind of unpredictable mental stimulation that routine daily tasks simply cannot replicate.
Older Australians are at particular risk of isolation. Retirement, the loss of a partner, mobility difficulties, and the end of driving can all remove the social structures that kept a person connected. For many people, this happens gradually and quietly. By the time it is obvious, the withdrawal has already been significant.
Research from Australian and international sources consistently identifies social isolation as a major risk factor for cognitive decline. Dementia Australia highlights loneliness and social disconnection as significant contributors to the conditions that increase dementia risk.
Mental stimulation matters too. Activities like reading, learning new skills, playing games, engaging with creative pursuits, and even doing crosswords appear to support what researchers call cognitive reserve, the brain’s ability to cope with damage or decline by drawing on alternative pathways and networks.
At Fleet Healthcare, we think about this when we work with clients at home. Therapy is not just about physical outcomes. Conversations matter. Engagement matters. Sometimes the most important thing a home visit does is give someone a reason to think, prepare, and interact with another person that day.
Removing the barriers to better health includes removing the barriers to connection. For people who cannot easily leave home, we aim to bring not just clinical support, but meaningful human interaction as part of the care we provide.
High Sugar and Ultra Processed Diets
Can poor diet lead to memory loss? The relationship between what we eat and how our brain functions is increasingly supported by Australian research, and the evidence is worth taking seriously.
Diets high in added sugars, refined carbohydrates, and ultra processed foods are associated with conditions that increase dementia risk. These include type 2 diabetes, obesity, high blood pressure, and high cholesterol. Each of these conditions, particularly when poorly managed over time, can affect blood flow to the brain and increase the likelihood of vascular changes that contribute to cognitive decline.
Type 2 diabetes in particular has a well documented relationship with dementia. Chronically elevated blood sugar levels can damage the small blood vessels in the brain and affect how brain cells use energy. Some researchers have even described Alzheimer’s disease in terms of impaired insulin signalling in the brain, although this area of research continues to develop.
Ultra processed foods are a growing concern. These are products that are heavily manufactured, contain multiple artificial additives, and bear little resemblance to their original ingredients. They tend to be calorie dense, nutritionally poor, and engineered to be consumed in large quantities. When these foods make up the majority of someone’s diet, the nutritional gaps and systemic inflammation that result can have real effects on brain health over time.
A diet built around whole foods, vegetables, legumes, whole grains, fish, and healthy fats is consistently associated with better cognitive outcomes. This is not about perfection. It is about patterns. Small, sustainable shifts in the direction of whole food eating can make a meaningful difference, especially when combined with other healthy habits.
For older Australians managing their nutrition at home, this is an area where allied health support can be genuinely useful. Occupational therapists and dietitians can help with meal planning, preparation strategies, and practical modifications that fit the person’s actual environment and capabilities.
Smoking and Excessive Alcohol Consumption
These two are often discussed together, and for good reason. Both smoking and heavy alcohol use are independently linked to cognitive decline, and together they compound risk significantly.
Smoking damages the cardiovascular system and reduces the brain’s oxygen supply. It increases the risk of stroke, small vessel disease, and chronic inflammation, all of which can directly harm brain tissue. Long term smokers show measurable reductions in brain volume in areas associated with memory and executive function. The good news is that quitting at any age reduces these risks, and the brain begins to benefit relatively quickly after cessation.
Excessive alcohol is more complex, because small to moderate amounts are not consistently associated with harm in the research. However, heavy or chronic alcohol use is another matter. It is directly neurotoxic, meaning it damages brain cells. It also disrupts sleep, depletes critical nutrients including B vitamins, and is associated with a specific form of dementia related to thiamine deficiency, known as Wernicke Korsakoff syndrome.
In clinical practice, I am careful not to lecture people. These are sensitive areas, and most people already have some awareness of the risks. What I find more useful is exploring what role these habits are playing in someone’s life, whether there are other needs being met that could be addressed differently, and whether there is appetite for change.
For families, this is worth approaching with patience and care. Shame rarely helps. Practical support, including access to the right health professionals, often does. GPs, psychologists, and community health services in Australia can all assist with reducing or stopping smoking and alcohol use.
Untreated Hearing Loss and Cognitive Strain
How does hearing loss relate to dementia? This is a question I get less often than I should, because the connection is one of the most significant and least discussed risk factors in the field.
Untreated hearing loss has been identified as one of the largest modifiable risk factors for dementia. When someone struggles to hear, the brain works much harder to process sound and fill in gaps in conversation. Over time, this cognitive load can reduce the mental resources available for other functions, including memory and attention.
There is also a social dimension. People with hearing loss often withdraw from conversations and social situations because the effort required is exhausting and the experience of mishearing or misunderstanding is embarrassing. As we have already discussed, social isolation is itself a significant risk factor for cognitive decline. Hearing loss can be a gateway to that isolation.
The brain also adapts in ways that are not always beneficial. When auditory input is consistently reduced, the regions of the brain that process sound begin to change. Some of this cortical reorganisation may have downstream effects on broader cognitive networks.
The encouraging thing is that treating hearing loss appears to reduce this risk. Hearing aids, when worn consistently, have been associated with a reduced rate of cognitive decline in people with hearing impairment. Getting a hearing assessment, and acting on the results, is a concrete and relatively simple step that can have a meaningful impact on long term brain health.
If you are supporting an older person who avoids phone calls, asks for things to be repeated frequently, or has turned up the television volume significantly, it is worth encouraging a hearing assessment. GPs can provide a referral, and audiology services are available across Australia.
Chronic Stress, Anxiety and Depression
Mental health and brain health are not separate conversations. They are part of the same one.
Chronic stress triggers the release of cortisol, the body’s primary stress hormone. In small doses and short durations, cortisol is helpful. But when stress is sustained over months and years, elevated cortisol has a measurable and damaging effect on the hippocampus, the part of the brain most associated with memory and spatial navigation. This is the area affected earliest in many forms of dementia.
Anxiety and depression are also independently associated with increased dementia risk. This does not mean that everyone with anxiety or depression will develop dementia. The relationship is more nuanced than that. But it does mean that untreated, long term mental health conditions carry real brain health implications that deserve to be taken seriously.
One of the things I observe regularly in home visits is the extent to which chronic worry, grief, loneliness, and unresolved stress quietly shape someone’s daily functioning. These are not minor background concerns. They affect sleep, motivation, appetite, social engagement, and the overall texture of someone’s life. When they persist without support, they erode the foundations of good cognitive health.
Care that works in the real world has to account for this. Physiotherapy and exercise can play a meaningful role in managing stress and supporting mood. So can social engagement, routine, purposeful activity, and access to psychological support when needed.
If you or someone you care for is living with chronic anxiety, depression, or overwhelming stress, that is worth addressing with a GP or mental health professional. Beyond Blue and the Black Dog Institute are two trusted Australian organisations with resources and support pathways
What the Research Says About Prevention
The evidence on dementia prevention has matured considerably over the past decade, and the picture it presents is genuinely hopeful, even while being honest about the limits of what is currently known.
The 2024 Lancet Commission on Dementia Prevention, Intervention and Care identified 14 modifiable risk factors that together account for around 45% of dementia cases globally – meaning nearly half of all dementia cases could potentially be prevented or delayed by addressing these factors. These include low education in early life, hearing loss, high blood pressure, obesity, smoking, depression, physical inactivity, social isolation, excessive alcohol use, traumatic brain injury, air pollution, diabetes, untreated vision loss, and high LDL cholesterol. The final two were added in the 2024 update to the Commission’s report, expanding the list from 12 to 14 factors. (Source: Lancet Commission on Dementia Prevention, Intervention and Care, 2024)
What this means in practical terms is that a substantial number of dementia cases may be preventable or delayable through lifestyle changes and better management of health conditions. This is not a guarantee. Genetics and other factors play a role. But it does mean that action taken at any stage of life carries real potential.
In Australia, the National Health and Medical Research Council (NHMRC) supports ongoing research into dementia prevention. Dementia Australia provides evidence based guidance for individuals, families, and health professionals.
The best ways to reduce dementia risk, based on current evidence, combine several approaches at once. Physical activity, social engagement, cognitive stimulation, healthy nutrition, quality sleep, hearing care, mental health support, and management of vascular risk factors all contribute. No single intervention is sufficient on its own, but together, they build a meaningful layer of protection.
What I tell families is this: the goal is not to prevent ageing. It is to age well. And ageing well is an active process, supported by the right habits, the right relationships, and the right professional care when it is needed.
When to Speak to a Health Professional
Knowing when to take action is often the hardest part. In my experience, people tend to wait longer than they should, either because they do not want to be alarmist, or because they are afraid of what they might hear.
But earlier is almost always better. Not because a diagnosis changes everything immediately, but because early support gives people more time, more options, and a better chance of maintaining independence for longer.
You should speak to a GP if you or someone you care for is experiencing any of the following: noticeable changes in memory that affect daily life, increasing difficulty with familiar tasks, confusion about time or place, changes in mood or personality that feel out of character, difficulty following conversations or finding the right words, or withdrawal from activities and social engagement that were previously enjoyed.
A GP can conduct an initial assessment, arrange cognitive testing, and refer to the appropriate specialists if needed. In Australia, people living with dementia and their carers can also access support through My Aged Care.
Allied health professionals, including physiotherapists and occupational therapists, also play an important role in supporting people living with dementia and those at risk. Physiotherapy can address the physical deconditioning, fall risk, and pain that often accompany cognitive decline. Occupational therapy can support safety, daily function, and environmental modifications that allow people to remain at home.
At Fleet Healthcare, we provide mobile allied health services that come directly to you. We work with NDIS participants, older Australians supported through the Support at Home program, DVA clients, and private clients across Australia. Not everyone can come to a clinic, so we bring the clinic to them.
Frequently Asked Questions
What habits can increase the risk of dementia?
A sedentary lifestyle, chronic poor sleep, social isolation, smoking, excessive alcohol use, an unhealthy diet high in processed foods and sugar, untreated hearing loss, and unmanaged mental health conditions including anxiety and depression are all habits and factors associated with an increased risk of dementia. Most of these are modifiable, meaning that changes made at any age can reduce the level of risk.
Can poor sleep lead to memory loss?
Yes, chronic poor sleep is associated with an increased risk of cognitive decline and memory difficulties. During sleep, the brain clears waste products including amyloid beta, a protein linked to Alzheimer’s disease. Persistent sleep disruption, whether from sleep apnoea, pain, anxiety, or poor sleep habits, deprives the brain of this essential maintenance process. Addressing the underlying causes of poor sleep is an important step for both general wellbeing and brain health.
How does hearing loss relate to dementia?
Untreated hearing loss is one of the most significant modifiable risk factors for dementia. When the brain works harder to process incomplete sound signals, it places ongoing strain on cognitive resources. Hearing loss also contributes to social withdrawal, which is itself a risk factor for cognitive decline. Using hearing aids consistently, when recommended, appears to reduce this risk meaningfully.
What are the best ways to reduce dementia risk?
The evidence points to a combination of approaches: regular physical activity, quality sleep, social engagement, mental stimulation, a diet based on whole foods, not smoking, moderate or no alcohol, treatment of hearing loss, management of mental health conditions, and control of vascular risk factors such as high blood pressure and diabetes. No single strategy is sufficient on its own, but together these habits build a meaningful foundation for brain health.
Does lack of exercise increase dementia risk?
Yes. Physical inactivity is one of the most consistently identified modifiable risk factors for dementia. Exercise increases blood flow to the brain, supports neuroplasticity, reduces inflammation, and helps regulate blood pressure, blood sugar, and weight, all of which are linked to cognitive health. Even modest, regular movement has measurable benefits. A physiotherapist can help design a safe and sustainable exercise program for people of varying ability levels.
Is dementia purely genetic?
Genetics can play a role, particularly in early onset dementia. However, the majority of dementia cases involve a combination of genetic predisposition and lifestyle factors. Research suggests that a significant proportion of dementia cases could potentially be delayed or prevented through modifications to lifestyle and better management of health conditions. Having a family history of dementia is a reason to be proactive about brain health, not a reason to give up on prevention.
What are the early warning signs of dementia?
Early signs can include memory lapses that affect daily life, difficulty completing familiar tasks, confusion about time or location, trouble finding words or following conversations, changes in mood or personality, withdrawal from previously enjoyed activities, and problems with planning or problem solving. These signs warrant a conversation with a GP. Early assessment allows for earlier support and better outcomes.
How can Fleet Healthcare help someone at risk of cognitive decline?
Fleet Healthcare provides mobile allied health services in the home, including physiotherapy and occupational therapy. For people at risk of or living with dementia, we can support physical fitness and fall prevention, help maintain daily function and independence, and work with families and carers to ensure the home environment is as safe and supportive as possible. We work with NDIS participants, older Australians under the Support at Home program, DVA clients, and private clients.
Final Thoughts
I have been doing this work long enough to know that the people who age the best are rarely the ones who had perfect health. They are the people who stayed curious, stayed connected, kept moving, and kept asking for help when they needed it.
Dementia is not inevitable. The research is clear that lifestyle plays a significant role, and that the choices made across a lifetime shape the brain’s resilience. But this is not about living a life of restriction and discipline. It is about building habits that nourish the brain the same way we would nurture any other part of the body.
If you are reading this as a family member or carer, I want you to know that noticing these risks and acting on them is one of the most valuable things you can do. You do not need all the answers. You just need to start the conversation, with the person you care for, with their GP, and with the right allied health professionals.
If you are an older Australian reading this for yourself, the same applies. It is never too late to make changes that matter. And you do not have to navigate it alone.
The healthcare system can sometimes feel overwhelming and hard to access, particularly for people managing mobility challenges or living in areas where services are limited. That is exactly why we built Fleet Healthcare the way we did. We believe care should come to people. We believe therapy only works when it fits into someone’s actual life. And we believe that removing the barriers to better health is not a luxury. It is the whole point.
Whether you are exploring options for yourself, a parent, or someone in your care, we are here to help. Our allied health team provide in home support through the Support at Home program, NDIS, DVA, and private arrangements.
Book a mobile allied health consultation with Fleet Healthcare today.
Call our team or visit fleethealthcare.com.au to explore our services and find the right support for your situation.
Author Bio
Alex Hunt is the Founder and Managing Director of Fleet Healthcare, and a practising physiotherapist with over a decade of experience across NDIS, aged care, and mobile allied health. I am passionate about care that meets people where they are and delivers real results in everyday life.
Professional Disclaimer
The information provided in this article is for general informational and educational purposes only and does not constitute professional advice.
While we aim to ensure accuracy at the time of publication, professional standards, funding arrangements, eligibility criteria, and regulatory frameworks may change and may vary between providers and governing bodies.
Any references to funding or service access are general in nature and should be confirmed directly with the relevant provider or authority.
Fleet Healthcare Services Pty Ltd accepts no liability for actions taken based on the information provided in this article.
