The Blood and the Brain – where is the link?

Dementia affects many of us, with devastating effects on individuals, families and friends. While we currently lack effective treatments to prevent the condition, new research is constantly advancing and changing our understanding of the diseases which lead to it.

Just last week we reported news of a study from the US reporting that women who have high blood pressure in their 40s may have an increased risk of developing dementia. Yet dementia is caused by diseases that attack the brain, so many might ask the question, why are scientists looking at blood pressure?

High Blood Pressure

Well the simple answer is, blood is important too and accounts for a staggering 7% of the weight of a human body.

Every time your heart beats, it pumps your blood around your body so that your muscles and organs – including your brain – receive all the energy and oxygen they need to survive and carry out their functions.

To do this, your heart pushes your blood through a complex network of blood vessels called arteries. As the blood travels through the arteries it pushes against the sides of these vessels, and the strength of this pushing is your blood pressure.

High blood pressure is also known as hypertension and affects one in four adults in the UK. It can lead to various health conditions, the most well-known being heart attacks and strokes. The need to lower your blood pressure is something we hear about regularly, and although it can be tackled by medicines, it can also be modified by lifestyle changes.

We know too that high blood pressure can be a risk factor for dementia but it is important to find out more about how, why, who this can impact and at what point in someone’s life it has the biggest impact.

The link to dementia research

Vascular dementia is the second most common cause of dementia, affecting 150,000 people in the UK, with symptoms similar to Alzheimer’s. If laid end-to-end, all of the blood vessels in the brain would reach almost 100,000 miles in length, but during vascular dementia, the brain doesn’t receive enough blood through these vessels, and therefore is also starved of oxygen. This causes nerve cells to become damages and affects how well areas of the brain work, which can have devastating impacts on someone’s life. We also know that blood flow to the brain is reduced in people with Alzheimer’s disease, and this may be part of the reason nerve cells are dying in this form of dementia too.

More and more studies are linking high blood pressure to increased risk of dementia, with studies linking high blood pressure to the loss of brain cells, risk of stroke and alterations in the blood flow to the brain. Yet these interactions are complex and difficult to study, and the exact reasons underlying the onset of disease remain blurred.

Your support is making a difference

But thanks to your support, research is under way to tackle this. Thanks to your funding, a team of scientists at the University of Bristol is investigating the link between high blood pressure and dementia by looking at the brain’s structure under the microscope.

They are measuring whether high blood pressure in a group of people with Alzheimer’s disease had affected blood flow, blood vessel damage, and levels of the amyloid protein in the brain – a key hallmark of the disease. This work has the potential to identify stages where we could intervene most effectively to limit the damage of high blood pressure on the brain.

Sadly, unlike Alzheimer’s, there are currently no treatments to tackle the symptoms of vascular dementia aside from treatments to manage vascular risk factors like high blood pressure. To find out more about vascular dementia and to hear from Cambridge University’s Professor Hugh Markus watch this clip.

We have previously blogged about the fact Alzheimer’s Research UK is funding £4 million of pioneering research to better understand the condition and help overcome the hurdles faced in developing ways to help those affected.

Reducing your risk of dementia

Not only can people manage high blood pressure with drugs, but lifestyle changes can also help. Over the years we’ve also built up a solid base of evidence that ‘what’s good for your heart is good for your brain’. This includes advice that many of us are already familiar with for other health conditions, such as eating healthily, keeping physically active and managing high blood pressure.

Yet it’s less well known that this advice can also stand true for dementia risk. Steps to look after our heart health could also help reduce the risk of dementia, including lifestyle approaches such as: quitting smoking, being physically active, eating healthily, maintaining a healthy weight, drinking less alcohol, and keeping mentally active. As dementia risk is a complex mix of age, genetic and lifestyle factors, these measures don’t give you blanket cover, but they might help reduce your overall risk of dementia and that can only be something worth pursuing.

What you can do

Dementia is not a natural part of ageing, it is caused by diseases that attack the brain – and diseases can be defeated through research. Find out more about the pioneering research projects we’re funding on our website or find out more about reducing your risk of dementia, download our free booklet.

Do you believe in the power of research to make breakthroughs possible?  Support our pioneering research at

1 Comment

  1. SueG on 15th October 2017 at 6:05 pm

    Sugar is never mentioned. Mum was fit, ate healthily, played bridge, walked dogs every day but she still got Alzheimers. However, she was a chocoholic often eating a large bar of Cadburys whole nut a day and often a glass or two of sherry. She also had high blood pressure and low thyroid which was controlled with drugs for many years and was regularly checked by her GP

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About the author

Ed Pinches

Team: Science news