What is Alzheimer's Disease?

Understanding Alzheimer's disease, what causes it and how does it affect the brain over time.

 

 

Key points

  • Alzheimer's disease is the most common form of dementia.1
  • It progressively affects memory, thinking and behaviour, with short-term memory loss being one of the first noticeable symptoms.
  • The causes of Alzheimer's disease remain unknown, though several risk factors can increase your chances of developing the condition.
  • Over time, nerve cells in the brain lose their ability to communicate with each other and gradually begin to die, causing brain shrinkage and affecting day-to-day functioning.

Alzheimer’s disease is the most common form of dementia and the second leading cause of death among Australians,1 affecting memory, thinking and behaviour.  An estimated 433,300 Australians are living with dementia in 2025,1 and an additional 1.7 million people play a role in caring for those affected.1,2  This number is projected to almost double by 2054, impacting 812,500 Australians.1

 

Alzheimer’s is a physical brain condition characterised by the gradual decline of functions such as impaired memory, language, thinking and behaviour. It causes progressive damage to the brain cells responsible for carrying messages to each other, making them less able to communicate until these cells eventually die, and the brain beings to shrink.2

 

Anyone can develop Alzheimer's disease, and the exact causes are still unknown. The condition becomes more common as you get older, most often over age 65. It’s the most common form of dementia,2 affecting people with or without a family history of the disease. Other factors including a lack of physical or mental exercise, smoking, obesity and diabetes can further increase your risk.2

 

 

Causes of Alzheimer’s disease

The causes of Alzheimer’s disease are not yet fully understood, however research has identified several factors which can increase a person's risk of developing the condition. 2,3

 

 

Having a family history (first degree relative) of Alzheimer’s disease means you are more likely to develop the disease, compared to those with no history. 

Certain gene variants have been shown to increase the chances of developing Alzheimer’s disease.

Ageing is the largest risk factor for Alzheimer’s disease, with the likelihood of developing the condition doubling every 5 years from age 65 onwards.3

MCI can sometimes progress to Alzheimer’s disease. MCI affects your ability to think, however unlike mild or moderate Alzheimer’s disease, it doesn’t normally affect your ability to perform day-to-day tasks. Experiencing MCI increases your risk of developing Alzheimer’s disease. Read more on the differences between MCI and Mild Alzheimer’s disease here. 

Having other health conditions like cardiovascular disease or traumatic brain injury may also increase your risk of developing Alzheimer’s disease.

What happens to the brain during Alzheimer’s disease?

In a healthy brain, neurons constantly adjust or repair themselves and their connections to other neurons – which includes strengthening or weakening synaptic connections, or breaking connections with one group of neurons and forming new connections with another group.4

 

With Alzheimer's disease, the neurons in your brain are damaged over time and the loss of synaptic connections is accelerated, until neurons can no longer communicate with each other normally. Eventually these nerve cells die, and your brain starts to shrink, resulting in symptoms such as memory loss, slowed thinking and behavioural changes.4,5 While this occurs at different speeds and severities for different people, the changes to your memory, thinking and behaviour will become more noticeable over time as the disease progresses.4

 

With Alzheimer’s disease, the loss of these synapses becomes accelerated. It is not yet understood why this is the case, however research suggests this starts to happen very early in the onset of the disease. This is one of the key features of early Alzheimer’s disease.4

 

Often the first areas of the brain to be affected are the hippocampus and its connected structures.4 The hippocampus is an area of the brain responsible for short-term memory storage and retrieval. When this is damaged, it can become more difficult to remember what you did that day, or what you've just said – which are some of the  first noticeable symptoms of Alzheimer’s disease. Beyond this, other brain functions and behaviours can also be impacted and recognised as initial symptoms.

 

 

A bottle and tin of Souvenaid surrounded by it's key nutrients

Souvenaid® and Alzheimer's disease

Everyday tasks like cooking, shopping, or even remembering appointments can become challenging with Alzheimer's disease.What we consume in our daily diet plays an important part in allowing neurons in the brain to communicate with each other.  The brain needs key nutrients – including omega-3 fatty acids, phospholipids, choline, uridine monophosphate and B vitamins – in the right combinations and quantities to nutritionally support the growth of brain connections. Souvenaid® has been specially formulated to provide these essential nutrients, at levels otherwise difficult to achieve through normal diet alone.

 

Souvenaid® is formulated to provide a unique blend of nutrients  in the quantities needed to support the formation of new synapses.

 

 

 

Souvenaid is a Food for Special Medical Purposes for the dietary management of early Alzheimer’s disease. Must be used under medical supervision. Souvenaid does not cure or alleviate Alzheimer’s disease.

 

The information on this page is not intended to be a substitute for medical advice. Always seek medical advice from a healthcare professional.

 

 

 

  1. Dementia Australia. Dementia facts and figures [Internet]. Australia: Dementia Australia; 2025 [cited 2025 Mar 05]. Available from: https://www.dementia.org.au/about-dementia/dementia-facts-and-figures
  2. Dementia Australia. Alzheimer's disease: everything you need to know [Internet]. Australia: Dementia & Alzheimer's Australia; 2024 [cited 2025 Feb 04]. Available from: https://www.dementia.org.au/about-dementia/alzheimers-disease-everything-you-need-know#about-alzheimer's-disease
  3.  Alzheimer’s Association. Risk factors for Alzheimer’s [Internet]. Chicago: Alzheimer's Association; 2025 [cited 2025 Feb 04]. Available from:  https://www.alz.org/au/dementia-alzheimers-australia.asp
  4. National Institutes of Health. What Happens to the Brain in Alzheimer's Disease? [Internet]. 2024 [cited 2025 Feb 20] Available at: https://www.nia.nih.gov/health/alzheimers-causes-and-risk-factors/what-happens-brain-alzheimers-disease  
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