High cholesterol levels may raise Alzheimer’s risk

HAVING high cholesterol could put you more at risk of Alzheimer’s disease, scientists believe.

And new research suggests that taking cholesterol-busting statins could help reduce the chances of developing the condition.

Experts have known for years that ‘bad’ LDL cholesterol can clog up arteries and increases the risk of heart disease.

But the link with Alzheimer’s has been less clear cut.

Some doctors argue that there could be a connection as blocking up blood vessels restricts blood flow to the brain. Others point out that the genes which increase the risk of Alzheimer’s also increase cholesterol.

Now a study led by researchers at Emory University in the US has gone some way to clearing up the debate.

They sequenced the genes of 2,125 people – 654 of whom suffered with early-onset Alzheimer’s. They found just 13 per cent of those with the condition had genetic mutations that increased their risk.

Once that was taken into account, the researchers found that those with Alzheimer’s but without the risk genes still had significantly higher levels of cholesterol – suggesting it does play a role.

Study leader Dr Thomas Wingo, whose findings are published in the medical journal JAMA Neurology, said: ‘The existing data has been murky. One interpretation of our current data is that LDL cholesterol does play a causal role.

‘If that is the case, we might need to revise targets for LDL cholesterol to help reduce Alzheimer’s risk.’

The disease is the most common form of dementia, affecting roughly 500,000 people in the UK. This number is expected to double by 2051.

About 12million people in Britain are currently eligible to take statins to reduce their cholesterol levels. But only about half do so, meaning roughly 6million people are missing out on the medication.

Part of this is because of controversy over whether people who have no health problems should be given drugs in an attempt to prevent health problems in later life. Critics describe this as ‘over-medicalisation’.

Dr Jana Voigt, head of research at Alzheimer’s Research UK, said: ‘There is good evidence linking high levels of cholesterol to an increased risk of Alzheimer’s disease.

‘While the vast majority of people with Alzheimer’s begin to experience symptoms after the age of 65, this study linked high levels of so-called bad cholesterol to the rarer, early-onset form of the disease.

‘Many people know high cholesterol is a risk factor for heart disease and other health conditions, but they don’t realise it’s a risk factor for dementia too.’

Dr James Pickett, head of research at the Alzheimer’s Society, added: ‘We cannot currently slow down, stop or cure dementia but understanding more about the tiny changes that take place in the brain may help us make progress.

‘This is why the suggested link between cholesterol and youngonset Alzheimer’s disease in this study could be significant.

‘It is still difficult to know if this relatively small study has the answers to the relationship between raised LDL cholesterol levels and young-onset Alzheimer’s disease, as we cannot be certain that there is a causal relationship here.

‘What we do know is that a healthy diet, regular exercise and avoiding smoking and drinking too much alcohol can reduce dementia risk, as what’s good for the heart is good for the head.’

‘Study could be significant’