Why do some people develop dementia, while others live to a ripe old age with their mind as sharp as a 20 year olds? We don’t yet know the answer to this question. What we do know is that several things affect your risk of developing dementia – your age, your genes, certain health factors and your lifestyle.
Old age is the largest risk factor for dementia
Dementia mostly affects older people, and the risk of dementia increases with increasing age. The older you are, the more likely you are to be affected by dementia. Approximately 1 in 70 people aged 65-69 have dementia. Nearly 1 in 4 people aged 85-89 have dementia.
It is rare for someone under 65 to have dementia, but it can occur at younger ages and we call this ‘younger onset dementia’.
Your genes may affect your dementia risk
People often wonder whether dementia is inherited. The answer for most of us is, no. The common forms of dementia are likely caused by a combination of genetic and environmental factors.
If you have a family history of dementia, you have a higher risk of developing it yourself compared to people with no history of dementia in their family. That doesn’t mean that you will definitely get it, just that you have a slightly increased risk.
Where does this increased risk come from? There are ‘susceptibility genes’ that we might inherit from our parents that increase the risk of developing dementia. One susceptibility gene has been found for Alzheimer’s disease, but there are likely to be others.
Some people with susceptibility genes will develop dementia but others won’t. And some people will develop dementia even though they don’t carry these genes. So they are just a risk factor, not a cause of dementia.
There are a few very rare forms of inherited dementia. In these families, a particular gene is passed down that directly causes dementia.
Looking after your health can reduce your dementia risk
High blood pressure, high cholesterol, diabetes and obesity are risk factors for dementia. Many studies have shown that people with one of these conditions during midlife are about twice as likely on average to develop dementia later in life. If you have more than one of these conditions, your risk is increased even more.
You can’t do anything about getting older or your genes, but you can do something about your health. See your doctor for regular health checks and follow your doctor’s treatment advice.
Keeping your blood pressure, cholesterol, blood sugar and weight at healthy levels is important for your brain and your heart. See our Mind your Health Checks pages for more details.
Your lifestyle choices can reduce your dementia risk
What you eat and drink, whether you smoke and whether you exercise your body and brain all affect your dementia risk. And you can do something about the lifestyle choices you make.
A healthy diet low in saturated fat and including lots of fruit and vegetables is associated with a lower risk of dementia. See our Mind your Diet pages for more details.
Drinking alcohol in moderation and not smoking are associated with a lower risk of dementia. See our Mind your Habits pages for more details.
Regular physical exercise is associated with a lower risk of dementia. See our Mind your Body pages for more details.
Regularly exercising and challenging your brain with mental and social activities is associated with a lower risk of dementia. See our Mind your Brain and Mind your Social Life pages for more details.
