Dementia is a collective term for a range of conditions that affect various aspects of the way we think including memory, judgement, understanding and language. This is often accompanied by changes in personality and the ways in which the affected person interacts with those around them.
As time goes on and the dementia worsens, the person's ability to look after themself deteriorates, eventually to the point where they need full-time care and treatment.
Dementia is rare before the age of 60 but the risk of developing it increases rapidly after that with the incidence rising from around one in 20 in people aged over 65 to as many as one in five people aged over 75.
Three main types of dementia are recognised although it's important to understand that people who develop dementia often show signs of a combination of these - this is often referred to as 'mixed dementia'.
Alzheimer's disease makes up at least half of all dementia cases and involves the brain shrinking in size, a loss of neurons (brains cells) and reduced amounts of neurotransmitters (brain chemicals that send messages between neurons). Small plaques also form throughout the brain although their involvement in Alzheimer's disease isn't yet fully understood.
Vascular dementia involves the gradual blocking of tiny blood vessels in the areas of the brain responsible for thinking. This deprives the brain tissues beyond the blockage of blood and oxygen causing them to become damaged and die.
It's like having countless strokes that are so tiny they go unnoticed, but over time their collective effect builds up until thought processes become increasingly affected. Vascular dementia therefore has the same range of risk factors as cardiovascular disease and makes up around 25% of all dementia cases.
Dementia with Lewy bodies causes around 15% of dementia cases and involves the development of abnormal protein deposits called Lewy bodies with the neurons of the brain. Like the plaques that occur with Alzheimer's disease, it's not clear exactly what part the Lewy bodies play in the dementia process but they are know to significantly affect the normal workings of the brain.
A small proportion of dementia cases can also be caused by a wide range of other conditions that affect the brain such as alcoholism, significant or repeated head trauma and ongoing vitamin B deficiency.
You are also at increased risk of developing dementia if your DNA contains certain genes associated with Alzheimer's and if you already have other associated conditions such as Parkinson's disease, type 2 diabetes, cardiovascular disease and depression.
Dementia is a global health concern and it's on the rise - in fact, the number of people killed by dementia has increased three-fold in the last 20 years and dementia prevalence is expected to double to 75 million by 2030.1
Although medications can help with some cognitive and behavioural symptoms, there is no cure for dementia and it can't be reversed. Dementia is therefore a condition where a preventive lifestyle is particularly vital, especially from middle-age onwards.
Dementia is a terrible and distressing disease that slowly erases a person's ability to think, remember and function - but although increasing age is the most significant risk factor, it is not a natural part of the ageing process and you can take steps to reduce your risk by:
• Eating a healthy complex carbohydrate-based diet rich in fruit, vegetables and oily fish and low in fat, sugar and salt
• Maintaining a healthy body weight
• Avoiding tobacco use and second-hand tobacco smoke
• Keeping mentally active
• Maintaining healthy social relationships.
By following these simple lifestyles, you'll significantly reduce your risk of developing not only dementia but also a whole host of other common and life-threatening health conditions including cardiovascular disease, diabetes and cancer. You'll have a better chance of a longer life - and you'll also live that life with greater health and energy.
1. The Epidemiology and Impact of Dementia - Current State and Future Trends: World Health Organization (2015)