Dementia is one of the fastest-growing health challenges facing Australia. More than 433,000 Australians are currently living with dementia, and without a medical breakthrough this number is projected to increase to more than 812,000 by 2054.
According to a recent report from the Australian Institute of Health and Welfare, dementia is now the leading cause of death in Australia, being the leading cause of death for women and second to heart disease for men.
While age remains the strongest risk factor, research shows that dementia is not an inevitable part of ageing. In 2025, there are an estimated 29,000 people living with early onset dementia, and this is expected to increase to 41,000 by 2054. This can include people living in their 30s, 40s and 50s.
With age being the strongest risk factor for most cases of dementia, The Lancet Commission on Dementia Prevention, Intervention and Care (2024) has identified 14 modifiable risk factors that account for up to 45% of dementia cases worldwide. While we cannot control genetics, family history or age, we can take control of how we live across the lifespan, and Australians can reduce their individual risk and help ease the broader social and economic burden of dementia.
Lower levels of education in childhood and adolescence are linked with higher dementia risk later in life. Ensuring good quality education is available for all and by encouraging cognitively stimulating activities in midlife can help build and protect cognition and brain reserve.
How you can take action: Encourage lifelong learning. Even if early schooling was limited, continuing education, picking up new skills, or challenging your brain with puzzles and hobbies can help.
High blood pressure in midlife is a significant risk factor for dementia. High blood pressure can cause vascular damage to both small and large blood vessels in the brain.
How you can take action: Get regular blood pressure checks, reduce salt intake, exercise regularly, manage stress, follow medical advice and take any prescribed medication as directed to protect your blood vessels.
Excess body weight, particularly in midlife, is linked to diabetes, heart disease, and inflammation—all of which increase dementia risk. Studies show that larger waist sizes, not just overall weight, are linked to higher chances of cognitive decline and dementia, especially in people over 65.
How you can take action: Aim for a healthy weight through balanced eating and regular physical activity. Even small amounts of weight loss can improve long-term health.
Untreated hearing loss in midlife is one of the strongest known risk factors. It may reduce brain stimulation and lead to social isolation and depression, which are also risk factors for dementia.
How you can take action: Get regular hearing checks. If you need hearing aids, use them early, as studies show people with hearing loss that used hearing aids have a significantly lower risk of cognitive decline and dementia.
Studies show that drinking more than about 21 UK units (in Australia this is around 16-17 standard drinks) per week is linked to a higher risk of dementia and reduced brain grey matter.
However, the research also showed that light-moderate drinking appears to be associated with a slightly lower risk than not drinking alcohol at all.
How you can take action: Stick to the Australian guidelines of no more than 10 standard drinks a week and no more than 4 standard drinks on any one day.
People who have had a traumatic brain injury (TBI) have a higher risk of developing dementia—about 1.6–1.8 times higher than those without TBI. The risk is higher for younger people (<65 years) and men.
TBIs can come from road accidents, falls, violence, alcohol-related incidents, and repeated head injuries, especially in contact sports. Even mild TBI or concussion may increase dementia risk, though studies are mixed.
TBI may cause dementia through direct brain damage, leading to issues like abnormal protein buildup, brain inflammation, and brain atrophy. Some studies show that TBI can result in earlier onset of dementia by 2–3 years.
How you can take action: Wear helmets when cycling and protective wear when playing contact sports, use seatbelts, and prevent falls around the home or out and about.
Smoking in midlife (roughly ages 33–50) increases the risk of developing dementia later in life. The risk is higher for current smokers than for people who have never smoked.
Studies show that people who quit smoking have a lower risk of dementia than those who continue to smoke, and quitting is especially beneficial for those who smoked before age 65.
Smoking narrows blood vessels, reduces oxygen to the brain, and increases stroke and dementia risk.
How you can take action: Quitting at any age lowers dementia risk. Start by speaking to your local pharmacist or GP about over-the-counter options to assist with smoking cessation, and seek support through quit programs or counselling.
Depression is linked to a higher risk of developing dementia. Studies show that adults with depression—whether in early, middle, or late life—are about 2–3 times more likely to develop dementia than those without depression. In late life, some depression may actually be an early symptom of dementia rather than a cause.
The exact reasons are not fully clear, but depression may increase dementia risk by reducing social contact, self-care, or through biological effects like high stress hormones or inflammation that damage the brain.
How you can take action: Prioritise mental health. Talk to a GP or counsellor, stay socially connected, and consider therapy, medication, or lifestyle changes to support mood.
Research shows that the relationship between exercise and dementia goes both ways: people who are more active tend to have a lower risk of dementia, but illness and early dementia can also make people less active. Despite these challenges, the evidence is now strong that regular physical activity lowers the risk of dementia, including Alzheimer’s and vascular dementia.
Exercise boosts blood flow, reduces inflammation, and promotes the growth of new brain cells.
How you can take action: Aim for at least 150 minutes of moderate exercise per week. Walking, swimming, cycling, and strength training all help. Incidental exercise also helps, try taking the stairs rather than the elevator or park the car a little further away from your destination and walk the extra distrance.
Getting type 2 diabetes in midlife is linked with a higher risk of dementia later on, while late-life diabetes may still be harmful but is less clearly linked. The longer someone lives with diabetes and the less controlled it is, the higher their dementia risk.
Diabetes may contribute to dementia by damaging blood vessels, increasing stroke risk, and causing problems with how the brain uses insulin. This can lead to inflammation and the build-up of the proteins amyloid and tau in the brain, processes also seen in Alzheimer’s disease.
How you can take action: Prevent or manage diabetes with regular exercise, a balanced diet, and medication if prescribed. Keep blood sugar levels in check. Speak with your local Diabetes Educator about ways of regularly checking blood sugar levels.
Social isolation and loneliness (for example, living alone, rarely seeing friends or family or not joining group activities) can lead to depression, inactivity, and reduced brain stimulation, all linked with an increased risk of dementia. Social connections may protect the brain by building mental resilience, encourage health habits and lower stress and inflammation. Brain scans of socially isolated people showed less brain grey matter in key brain regions, compared to people who were not socially isolated.
How you can take action: Stay socially engaged through friends, family, volunteering, or community activities. Online connections can help too. Join us for one of HMRI’s open days or community events.
Exposure to air pollution, both outdoors and indoors, is increasingly recognised as a risk factor for dementia. Fine particles (PM2.5 and PM10) from traffic, industry, and household sources (like wood or coal stoves) can damage the brain over time. Even small increases in PM2.5 are linked with higher dementia risk, and black carbon may be particularly harmful.
How you can take action: While individual control is limited, you can reduce exposure by avoiding heavy traffic areas when exercising, using air purifiers indoors, and supporting clean air initiatives.
New research has emerged that has reported high LDL cholesterol in midlife (under 65) is associated with a higher risk of developing dementia. Excessive brain cholesterol is associated with an increased risk of stroke and build-up of the proteins amyloid and tau which are seen in Alzheimer’s disease.
How you can take action: Reduce saturated and trans fats in your diet and opt for lower cholesterol alternatives that are high in soluble fibre, such as oats, legumes, fruits, nuts and seeds. Partake in regular exercise, and have your cholesterol levels checked regularly as required by your health professional. When lifestyle changes are not enough, a doctor may prescribe medication.
New evidence has emerged that vision impairment is associated with a higher risk of both dementia and cognitive impairment. Large studies found that older adults with vision problems had around a of developing dementia or cognitive impairment compared with those with normal vision.
How you can take action: Around 90% of all blindness and vision impairment in Australia is preventable or treatable if detected early. It’s important to get regular eye tests, generally every two years, unless specified by your healthcare professional.
Dementia is a major health challenge in Australia, but up to 45% of cases may be preventable through lifestyle changes. The earlier you start protecting your brain, the better—but even small adjustments in later life can make a difference.
By focusing on the 14 modifiable risk factors, Australians can take proactive steps across every life stage to safeguard their brain health and reduce the impact of dementia on families, communities, and the healthcare system.
