Several key risk factors for dementia have been identified:
- Medical history, particularly cardiovascular problems
- Lifestyle and environment
There is no single straightforward cause of dementia, and no way of definitely preventing it, but it may be possible for each of us to reduce our risk or at least delay the onset of dementia.
Dementia is an illness, not a normal part of growing older. Even at a very advanced age, most people do not have dementia.
However, age is the biggest risk factor for dementia Dementia affects about 2% of people aged 65 to 70, 5% of people aged 70 to 80, about 20% over 80 and 33% over 90.
Most of the research on the genetics of dementia is about Alzheimer’s disease. However, there are known genes that contribute to some of the risk factors for vascular dementia, such as high cholesterol levels, high blood pressure and diabetes.
Familial Alzheimer’s disease
It is a rare type of Alzheimer’s disease where there is a family link caused by a single defective gene, and usually affects people under the age of 65. So far, three different genes of this kind have been identified. Only a very few families worldwide are affected by each gene and most cases of early onset Alzheimer’s disease are not inherited in this way.
Researchers have identified a protein called apolipoprotein E (ApoE) which affects your chances of developing Alzheimer’s disease. There are three forms of ApoE: ApoE2, ApoE3 and ApoE4.
Having one or two copies of ApoE4 increases someone’s chance of developing the disease, but does not make it certain. Some researchers think that ApoE4 does not affect whether a person will get the disease but, rather, when they get it, causing people with ApoE4 to develop the disease before people with ApoE2.
People with Down’s syndrome are now living longer and are at particular risk of developing Alzheimer’s disease at an earlier age than usual. Estimates suggest that more than 50% of people with Down’s syndrome in the 50-59 age group have dementia.
Medical history, particularly cardiovascular problems
Conditions that affect the heart and blood circulation are particularly important for the risk of developing vascular dementia. High blood pressure, high cholesterol levels, diabetes, heart attacks, strokes and mini-strokes can all affect blood supply to the brain, leading to possible damage. Obesity in mid-life may also increase the risk of developing dementia.
Lifestyle and environment
Many people are already aware that their lifestyle – for example diet and exercise – can affect their risk of heart disease. The evidence is growing that the same factors also affect dementia risk. Following are few factors that may reduce the risk of dementia.
- A balanced diet
- Good amount of physical activity
- Cease smoking
- Reduce alcohol consumption
- Mental stimulation
- Preventing head injuries