Protecting brain health

Risk factors for dementia

Research has shown that there are some lifestyle and environmental factors (such as smoking or obesity) that can accelerate the onset or progression of dementia. However, the biggest risk factor for most of the conditions that can cause dementia is increasing age. Through no fault of our own, as we get older, changes occur across all the systems of our body. For reasons, many still not completely understood, this impacts our ability to remain healthy and keep active. For dementia and the associated neurodegenerative conditions there is good evidence that changes to our immune system and the deterioration of our cardiovascular health can increase our risk.

Another significant risk factor that we also have no control over is genetics.

A few relatively rare neurological conditions are directly caused by faulty, missing, or additional genes (such as Huntington’s disease and Familial Alzheimer’s), but the causes of most of the neurological conditions that can lead to dementia are much more complex, and these conditions have what’s known as a ‘high polygenic component’. Prof Valentina Escott-Price, UK DRI Group Leader at Cardiff, explains:

How to reduce the risk of dementia

While we cannot control ageing itself, or our genetic make-up, there are a number of other risk factors that we can influence. Research published in 2020¹ and updated in 2024² identified that around 45% of dementia cases could be prevented if 14 lifestyle risk factors were acted on. While there are some steps we can take as an individual, many of these factors are not as straightforward to address and a consequence of wider societal issues.

These included:

• Cardiovascular health: Aim to maintain systolic blood pressure of 130 mm Hg or less from around age 40 onwards.
• Hearing: Use hearing aids where needed for hearing loss and reduce hearing loss by protecting ears from high noise levels.
• Air pollution: Reduce exposure to air pollution and second-hand tobacco smoke.
• Head injury: Prevent head injury where possible (this is of particular significance in high-risk occupations and transport situations).
• Alcohol: Avoid alcohol misuse and limit drinking to less than 21 units per week.
• Smoking: Stop smoking.
• Depression: Looking after mental health and seeking help if required.
• Diabetes: Treating diabetes and reducing risk.
• Obesity: Taking steps to remain a healthy weight.
• Social isolation: Contact with others and the community.
• Education: All children should be given primary and secondary education.
• Exercise: Lead an active life into mid – and possibly later – life.
• Untreated vision loss: Take up any opportunities for screening and treatment for vision loss. 
• High cholesterol: Undertake any opportunity for cholesterol checking so that high ‘Low Density Lipoprotein’ (LDL) cholesterol can be detected and treated from midlife (LDL cholesterol is present in the blood and higher levels are associated with an increased risk of coronary heart disease).

Several of the risk factors for dementia, especially vascular dementia, relate to cardiovascular health, including high blood pressure, high cholesterol, smoking and diabetes. As outlined in the Lancet report, these are modifiable risk factors and a healthy lifestyle (exercise, good diet, avoid smoking and high alcohol consumption) can help reduce a person’s risk of dementia. 

Eating a Mediterranean-style diet that’s high in fruit, vegetables, cereals, nuts and healthy fats may also help as it has been linked with providing a range of health benefits, including lowering the risk of dementia. 

Be mentally active

Regularly doing activities that fire up your brain can help to lower the risk of dementia. In fact, a US study found that regularly reading, writing and playing games could help to delay the onset of dementia⁴.

There are numerous ways to stay mentally active. It could be tackling a crossword, reading, writing, listening to a podcast, starting a daily Wordle habit or learning something new – it all counts.

Be physically active

There is a saying that what’s good for the body is good for the brain. Whether it’s regularly going for a walk or taking part in an exercise class you enjoy, staying active helps to pump blood around the body. This delivers a vital supply of oxygen and nutrients to the brain to keep it healthy.

There are suggestions about the types of exercises and variations of activity that are particularly suitable for people living with dementia on Alzheimer’s Society’s website.

Be socially active

Maintaining connections with the outside world and interacting with others helps to engage our brains and guard against dementia.

A comprehensive study which looked at over 460,000 people across the UK with an average age of 57, found that social isolation was linked to a 26% increased risk of dementia⁵. This was separate from other risk factors including depression and loneliness.

The researchers found that people who reported high levels of social isolation were more likely to show changes in their brain volume in areas that are associated with problems that can affect memory, learning and concentration. They suggest that social isolation could be an early indicator of an increased risk of dementia.

So, call a friend, visit a neighbour, join a club, or start a social group. Social media can be a great way to find out about groups and activities in your local area, or look out for adverts in local shops, newspapers and magazines.

For more information about ways to reduce the risk of dementia, visit Think Brain Health, an initiative from Alzheimer’s Research UK which is built around the core prevention areas identified in the 2020 research. The campaign focuses on three key areas: taking care of your heart, staying mentally sharp and keeping connected to the people around you. It aims to encourage more people to consider making simple lifestyle tweaks to help lower their risk of developing dementia. Their Think Brain Health Check-in offers bespoke advice on smaller lifestyle tweaks that could be helpful.