Written by Josh Horsman
Alzheimer's Disease is the most common form of Dementia, responsible for around 40-70% of all cases. It is a degenerative disease which affects the brain, causing a decline in its functionality. This leads to outward symptoms of memory-loss, impaired judgement, confusion, disorientation, behavioral changes and even agitation or aggression. Affecting almost 44 million people globally, Alzheimer’s Disease is certainly one of the most significant health challenges facing the world today. But what are the causes? Who is at risk? And, what can be done to decrease the numbers of people affected?
The symptoms of Alzheimer’s Disease (AD) are caused when brain cells (also called neurons) begin to decay and die. This leaves the brain without sufficient power to perform all of its daily functions effectively and so, naturally, some functions begin to fail, manifesting in the outward symptoms of memory-loss, impaired judgement and confusion, amongst others.
The brain cells begin to break down because of an irregular build-up of proteins in and around the cells in the brains of those with the condition. These deposits of protein disrupt the brain’s ability to communicate internally between cells by causing a decrease in the numbers of neurotransmitters (chemical messengers) to send messages between the cells. Scientific research has suggested that the build-up of proteins that cause Alzheimer’s Disease may begin to occur several years before outward symptoms are noticeable, however once protein deposits have begun to build-up in and around the brain cells, the progression of AD is not reversible. Over time, areas of the brain begin to shrink as the condition progresses, with areas responsible for memory seeming to be the first to decline.
It is not yet known why such abnormal deposits of protein form in the brains of those with Alzheimer’s Disease, however scientific research has determined several factors which influence a person’s risk of developing the condition:
Age is undoubtedly the biggest risk factor for Alzheimer’s Disease. It is important to stress that the symptoms of Alzheimer’s Disease are distinctly separate from what should be considered ‘normal signs of ageing’, there is an undeniable correlation between age and likelihood of developing AD. Alzheimer’s is most commonly associated with those over the age of 65 and the statistics support this view with evidence suggesting that your risk of AD doubles every 5 years that you live past this age.
However it must also be mentioned that it is not exclusively the elderly that have Alzheimer’s, with one in every twenty cases of AD being found in those under 65 and an increasing awareness of young-onset Dementia which affects those aged 40 and under.
Many people, especially those who have cared for family members with Alzheimer’s Disease, fear that they too will develop the condition as a result of their genetics. The reality, however, is that Alzheimer’s Disease is seldom an inherited condition. In fact up to 99% of cases of AD are none-familial and are instead the result of other factors. But, in a small number of cases where several family members have had AD, the disease may be caused by genetics. If you believe you may be at risk of Alzheimer’s by inheritance, speak to your doctor who will be able to refer you to a specialist genetic counsellor.
A large body of research in recent years has focussed around investigating the link between a healthy lifestyle and a reduced risk of developing Alzheimer’s. It has long been thought that a range of lifestyle-related health conditions could be linked to Alzheimer’s and the following have been proven to increase the risk of AD in some cases:
In some rare cases, Alzheimer’s Disease can be triggered by Traumatic Brain Injuries (TBI), although its onset is unlikely to occur until several years after the initial incident.
People living with Down’s Syndrome are more at risk of developing AD in later life as Down’s also causes build-ups of protein in and around the neurons in the brain over time, in a similar way to Alzheimer’s Disease.