It is still unknown what actually causes the deterioration of brain cells, although there are several factors that are known to make an impact on the development of Alzheimer's disease.

Age

Age is the greatest factor in the development of Alzheimer's disease. The likelihood of developing the disease doubles every five years after the age of 65. However, it is not just older people who are at risk of developing the condition.

Family history

Alzheimer's disease can also be inherited, although the risk is only marginally higher than that of someone who has no family history of the condition. If Alzheimer's disease is inherited, symptoms may start at a relatively early age (between the ages of 35 and 60).

Down's syndrome

People with Down's syndrome are at a higher risk of developing Alzheimer's disease. This is because people with Down's syndrome have an extra copy of chromosome 21, which contains a protein that is found in the brain of those with Alzheimer's disease. Therefore, people with Down's syndrome have a higher-than-average amount of the protein, which could contribute to developing Alzheimer's disease.

Whiplash and head injuries

It has been found that people who have had severe whiplash or head injuries could be at a higher risk of Alzheimer's disease.

Aluminium

Aluminium is a naturally occurring substance that can be found in food and plants. It can also be added to products, such as pans, packaging and medicines. The body only absorbs a minimal amount of aluminium, which often leaves the body in urine.

It was suggested that aluminium could be a possible cause of Alzheimer's disease as research discovered that the 'plaques' and 'tangles' in Alzheimer's disease contained aluminium. However, further research has failed to prove a link between aluminium and Alzheimer's disease.