Cholesterol and dementia

Research has shown that there is a link between high cholesterol and an increased risk of developing dementia. On this page, our specialist Admiral Nurses explain what cholesterol is, the link with dementia, and how to lower your cholesterol levels.

What is cholesterol?

Cholesterol is a waxy substance found within the body. It is needed to build cells and produce vitamins, but if your cholesterol levels are too high, it can cause health problems.

The liver produces all the cholesterol your body needs. However, it can also come from:

• meat
• dairy products
• saturated and trans fats, which are found in foods like fatty meat, butter, cheese, fried foods and baked foods such as cakes, pastry and biscuits
• certain oils used in baking, such as palm oil and coconut oil

Types of cholesterol

There are two different types of cholesterol: high-density lipoprotein (HDL) and low-density lipoprotein (LDL), sometimes referred to as non-HDL cholesterol.

LDL/non-HDL cholesterol

LDL/non-HDL cholesterol is often referred to as ‘bad’ cholesterol because it can cause fatty build-ups in the arteries. These thick, hard accumulations of cholesterol narrow the arteries and increase the risk of heart attacks, stroke and other heart problems.

On this page, where we use the term ‘high cholesterol’, we are referring to high levels of ‘bad’ LDL cholesterol.

HDL cholesterol

HDL cholesterol is sometimes referred to as ‘good’ cholesterol, because at healthy levels, it may help protect against heart problems such as heart attacks or strokes.

The role of HDL in the body is to carry LDL away from the heart and back to the liver, where it can be broken down. However, HDL can only carry a small amount of LDL and cannot fully eliminate it from the body.

Normal vs high cholesterol

‘High cholesterol’ means having too much LDL/non-HDL cholesterol in the blood.

Your target cholesterol level will depend on many factors such as your age, risk of cardiovascular disease and any pre-existing health conditions. However, as a guide, a healthy level of LDL/non-HDL cholesterol is below 4mmol/L.

Who is at risk of high cholesterol?

High cholesterol levels are more common in people who eat a diet that is high in fat, smoke, drink too much alcohol, are overweight and/or lack physical activity.

You are also more likely to have high cholesterol if you are over 50, male, a woman who has been through the menopause, or of a South Asian or sub-Saharan African background.

High cholesterol can run in families.

How high cholesterol can affect your brain

High cholesterol can cause a build-up of two proteins – amyloid and tau – within the brain. These proteins create ‘plaques and tangles’ in the brain and are linked to developing Alzheimer’s disease.

High cholesterol can also cause damage to and blockages in the blood vessels which carry blood and oxygen to the brain. When the flow of blood and oxygen to the brain is interrupted, it may lead to vascular dementia.

The impact of high cholesterol on memory and cognition

High cholesterol is linked with an increased risk of dementia, resulting in problems with memory and cognition (thinking). These could include:

• difficulties with memory, particularly short-term memory – including forgetting names, places and dates; losing or misplacing items; and forgetting recent occasions and conversations
• difficulties with problem-solving, judgement and decision-making
• communication problems
• poor concentration and attention span
• changes in mood, behaviour and personality

How high cholesterol can affect your body

As well as leading to a build-up of proteins in the brain, high cholesterol levels can lead to heart problems and stroke as a result of blockages in the blood vessels throughout the body.

The link between cholesterol and dementia

Vascular dementia risk and cholesterol

High cholesterol can cause blockages in the blood vessels. This can affect the blood supply to the brain, increasing the risk of vascular dementia. It can also increase the risk of stroke, and almost one in three people who have a stroke go on to develop dementia.

Alzheimer’s disease risk and cholesterol

High levels of cholesterol in the brain can lead to a build-up of proteins that form plaques and tangles. These are strongly linked to developing Alzheimer’s disease.

Other types of dementia

There is some evidence that high cholesterol is associated with an increased risk of other types of dementia, including Lewy body dementia and frontotemporal dementia. While more research is needed into the link between high cholesterol and rarer forms of dementia, the strong association between high cholesterol and dementia overall means it is important to try to keep your cholesterol at a healthy level.

Cholesterol medication and dementia

Statins are a type of medication used to reduce cholesterol levels. Studies have shown that compared to people with untreated high cholesterol, people who take statins are about 30% less likely to develop Alzheimer’s disease and 7% less likely to develop vascular dementia. Overall, people with high cholesterol who take statins are around 20% less likely to develop any form of dementia than those with untreated high cholesterol.

Find out more about statins and their link to dementia.

Lowering your cholesterol levels to reduce your dementia risk

Research has suggested that reducing your cholesterol levels could decrease the likelihood of developing dementia.

Diet

Making changes to your diet could help to lower your cholesterol and therefore potentially reduce your risk of dementia – particularly cutting down on fatty foods that contain saturated fats. You will be able to see the type of fat and the amount a food contains on nutrition labels, which often use a ‘traffic light’ system where red indicates the food is high in fat, yellow is medium, and green is low.

Foods to avoid include:

• fatty meats like sausages, bacon, ham and meat pies
• cream and hard cheese, such as cheddar
• biscuits and cakes
• butter, lard and ghee
• food that is made with coconut or palm oil

Try to eat more of these foods:

• fruit and vegetables
• nuts and seeds
• oily fish
• wholewheat pasta, wholegrain bread and brown rice
• olive and rapeseed oils

Exercise

You should aim to do around two and a half hours of exercise a week. This can be broken down into small chunks. Any form of physical activity is helpful, as long as it increases your heart rate, for example:

• walking
• jogging
• swimming
• cycling
• fitness or dance classes
• sports like football, netball or tennis

Everyday physical activity also counts, such as housework, gardening, dog walking and washing the car.

How we can support you

To speak to a dementia specialist Admiral Nurse about cholesterol or any other aspect of dementia, please call our free Dementia Helpline on 0800 888 6678 (Monday-Friday 9am-9pm, Saturday and Sunday 9am-5pm, every day except 25th December) or email helpline@dementiauk.org. Alternatively, you can pre-book a phone or video call with an Admiral Nurse.