A common drug frequently prescribed to millions of Brits could majorly reduce the risk of dementia by 13%, a new study suggests. Poor heart health has long been linked to high cholesterol, yet new findings show the latter may also increase the chances of developing dementia. 

Cholesterol is a natural fatty substance found in the blood. However, when levels of low-density lipoproteins (LDL) - also known as ‘bad’ cholesterol - get too high, blood vessels can become clogged, increasing the likelihood of a heart attack and stroke. Scientists have now uncovered that people with reduced amounts of ‘bad’ cholesterol are less likely to develop dementia. LDL can be lowered naturally by eating healthily and exercising, yet commonly prescribed drugs called statins can help to reduce high cholesterol if lifestyle changes aren’t enough. 

Around 8 million Brits take the drug, which is well-known for protecting individuals from cardiovascular failures. Researchers from Hallym University College of Medicine in South Korea now say that statins could protect against dementia, too. 

For those with already low levels of LDL, less than 1.8mmol/L, taking statins could slash an individual's chances of getting dementia even further, scientists found. However, minimising LDL cholesterol to extremely low levels, below 0.8 mmol/L - didn't reduce dementia risk any more.

High levels of LDL are classed as more than 4mmol/L present in the blood.

Scientists examined data collected by 11 university hospitals, which followed several adults for at least 180 days after they had their cholesterol levels taken. Of these, 192,213 people had LDL levels less than 1.8 mmol/L and 379,006 patients had LDL levels more than 3.4 mmol/L.

Findings showed that those with reduced levels of ‘bad’ cholesterol were 26% less likely to be diagnosed with dementia compared with the other participants with higher levels and 28% less likely to get Alzheimer's disease.

The use of statins seemingly boosted protection against dementia, even when peoples' LDL levels were already on the lower side. Out of those tested, participants below 1.8 mmol/L, using statins reduced dementia risk by 13% and Alzheimer's by 12% compared with non-users.

Due to the research being observational, a clear cause couldn’t be established.

Dr Julia Dudley, Head of Research at Alzheimer’s Research UK, said : "Clinical trials will be key to understand what effects statins might be having on disease processes in the brain."

Dr Richard Oakley from the Alzheimer's Society added: "This study adds to our understanding by showing the strong connection between heart and brain health. Simply put, what is good for the heart is good for the head."