A common drug prescribed to help lower cholesterol levels has been found to cut dementia risk.
High cholesterol has long been linked to general poor health, but a recent study published in the Journal of Neurology and Psychiatry revealed it may also increase the risk of dementia.
It found people with lower levels of “bad cholesterol” in their blood are less likely to develop the memory robbing condition.
The study suggested that cholesterol-lowering statins, the most commonly prescribed drugs in the UK, also offered a boost in protection against dementia.
Cholesterol is a natural fatty substance found in the blood. Low-density lipoproteins (LDL) also known as “bad cholesterol” can raise the risk of a heart attack or stroke if they are too high.
But exercising and eating healthily can bring these levels down. Drugs called statins, which are given to around 8 million Britons, are also prescribed to those with high cholesterol if lifestyle changes are not enough, helping to prevent cardiovascular event.
However, researchers from Hallym University College of Medicine in South Korea claimed the drug could also protect against dementia.
The scientists analysed data collected by 11 university hospitals which followed adults for 180 days after they got their cholesterol levels tested and observed whether the patients went on to develop dementia in the study period.
Researchers identified 192,213 people with LDL levels less than 1.8 mmol/L and 379,006 patients with LDL levels more than 3.4 mmol/L.
Those with lower LDL levels were 26 per cent less likely to be diagnosed with dementia compared with those who had higher cholesterol levels.
These patients were also 28 per cent less likely to be diagnosed with Alzheimer’s disease.
However, if LDL levels dropped below 1.4 mmol/L, participants only had an 18 per cent lower risk of getting dementia or Alzheimer’s.
Plus, when LDL levels dipped below 0.8 mmol/L, the protective effect disappeared entirely.
Researchers found the drug statins did boost protection against dementia, even when participants LDL levels were already on the lower side.
For those below 1.8 mmol/L, dementia risk was reduced by 13 per cent and Alzheimer’ by 12 per cent in comparison to those who did not take statins.
Dr Julia Dudley, Head of Research at Alzheimer’s Research UK says: “High levels of LDL cholesterol were identified as a risk factor for dementia in last year’s Lancet Commission on dementia prevention.”
“The use of statins seemed to offer a protective effect – even in those who already had cholesterol levels within a lower range,” she added.
“However, dementia risk is complex and influenced by many factors. Without a detailed picture of what’s going on in the brain we do not know if there is a direct link between lower cholesterol and reduced dementia risk.”
Researchers explained that because it was an observational study, no firm conclusions can be drawn about cause and effect.
The authors concluded: “Low LDL-C levels (<70 mg/dL (<1.8 mmol/L)) are significantly associated with a reduced risk of dementia, including Alzheimer’s disease related dementia, with statin therapy providing additional protective effects.”
