Neurodegenerative conditions such as Alzheimer’s disease, Parkinson’s disease and other forms of dementia affect a growing number of Australians. While age and genetics are important risk factors, research is continuing to explore how modifiable factors—including cardiovascular and metabolic health, physical activity, sleep and nutrition—may influence brain health as we age.

One area receiving increasing attention is the relationship between insulin resistance, glucose metabolism and Alzheimer’s disease. Let’s explore what researchers mean when they use the term “Type 3 diabetes”—and the everyday habits that can support overall brain health.

Dementia is an umbrella term for a collection of symptoms involving changes in memory, thinking and everyday functioning. Alzheimer’s disease is the most common cause of dementia. Parkinson’s disease is a progressive neurological condition primarily affecting movement, although some people with Parkinson’s may also develop cognitive impairment or dementia.

These conditions are growing fast, dementia affects a significant number of Australians. In 2024, over 421,000 Australians were living with dementia.

You may have heard Alzheimer’s disease described as “Type 3 diabetes.” This isn’t an official medical diagnosis, but rather a term that has been used by some researchers to explore the relationship between Alzheimer’s disease, insulin signalling and glucose metabolism in the brain.

Insulin has important roles beyond regulating blood glucose, including within the brain. Research has identified abnormalities in insulin signalling and glucose metabolism in Alzheimer’s disease, contributing to ongoing investigation into how metabolic health may relate to neurodegeneration.

Importantly, this does not mean that diabetes and Alzheimer’s disease are the same condition, or that Alzheimer’s is simply caused by eating too much sugar. Alzheimer’s is complex and influenced by multiple factors, including age, genetics, cardiovascular health and other biological and environmental influences.

The good news? While there is no single strategy for protecting brain health, there are everyday habits that can support your overall health and wellbeing:

1. Support Metabolic Health

A balanced dietary pattern that limits foods high in added sugars and highly processed foods can support cardiovascular and metabolic health. Maintaining healthy blood glucose regulation is particularly important for people living with, or at risk of, diabetes.

2. Choose a Balanced, Nutrient-Rich Diet

Eating a varied diet rich in vegetables, fruit, whole grains, healthy fats and quality protein sources can support cardiovascular and metabolic health, both of which are important components of healthy ageing. Mediterranean-style dietary patterns are commonly associated with cardiovascular and metabolic health, both of which are important components of healthy ageing.

3. Prioritise Sleep

Sleep plays an important role in brain health, memory and recovery. Research is also exploring the glymphatic system—a pathway involved in clearing metabolic waste from the brain—and how its function relates to sleep and neurodegenerative disease.

Maintaining a regular sleep routine and prioritising adequate, good-quality sleep is an important part of supporting overall health and wellbeing.

4. Stay Physically Active

Regular physical activity supports cardiovascular health, strength, balance, mobility and overall wellbeing. Staying active is also an important component of healthy ageing and can help people maintain independence and participate in the activities they enjoy.

Maintaining comfortable movement can make it easier to stay physically active as we age. Chiropractors are trained to assess and manage a range of musculoskeletal complaints involving the spine, joints and movement.

For some people, chiropractic care may form part of a broader approach to managing musculoskeletal pain, maintaining mobility and supporting participation in regular physical activity.

Chiropractic care is not a treatment or preventive strategy for Alzheimer’s disease, dementia or Parkinson’s disease. Anyone experiencing changes in memory, cognition, movement or neurological function should seek appropriate medical assessment.

Brain health is complex, and there is no single food, exercise, treatment or lifestyle strategy that can guarantee protection against neurodegenerative disease. However, looking after your overall health—including metabolic and cardiovascular health, physical activity, sleep, nutrition and social connection—is an important part of healthy ageing.

Maintaining musculoskeletal health and mobility can also help you stay active and engaged in everyday life. If pain, stiffness or reduced mobility is making it difficult to stay active, book an appointment with one of our chiropractors to discuss whether chiropractic care could be appropriate for your musculoskeletal needs.

If you or someone you know is experiencing new or progressive changes in memory, thinking, behaviour, balance or movement, speak with your GP or another appropriately qualified healthcare professional for assessment.

Australian Institute of Health and Welfare (AIHW). (2024). Dementia in Australia. Australian Government.
– Supports discussion of dementia in Australia, including prevalence, disease burden and the different forms and causes of dementia.

de la Monte, S. M., & Wands, J. R. (2008). Alzheimer’s Disease Is Type 3 Diabetes—Evidence Reviewed. Journal of Diabetes Science and Technology, 2(6), 1101–1113.
– Supports discussion of the proposed “Type 3 diabetes” concept and research investigating impaired insulin signalling and glucose metabolism in Alzheimer’s disease.

Mittal, K., Mani, R., & Katare, D. P. (2016). Type 3 Diabetes: Cross Talk Between Differentially Regulated Proteins of Type 2 Diabetes Mellitus and Alzheimer’s Disease. Scientific Reports, 6, 25589.
– Supports discussion of biological pathways shared between Type 2 diabetes and Alzheimer’s disease and ongoing research into their metabolic relationship.

Nepozitek, J., Dusek, P., & Sonka, K. (2025). Glymphatic System, Sleep, and Parkinson’s Disease: Interconnections, Research Opportunities, and Potential for Disease Modification. Sleep, 48(1), zsae251.
– Supports discussion of sleep, glymphatic function and emerging research into their relationship with Parkinson’s disease and neurodegeneration.