Simple cholesterol checks could help predict dementia up to six years before a diagnosis, promising research suggested today, writes dailymail.co.uk.

“Previous studies have long linked having high cholesterol in middle age with a higher risk of developing the memory-robbing condition. But now scientists in Australia, who tracked almost 10,000 adults in their 70s, found those with stable levels had a “significantly” lower likelihood of receiving a diagnosis or showing cognitive decline.

Experts hope routine cholesterol checks could now be used to flag people with fluctuating cholesterol levels allowing patients to get treated earlier. But the researchers, who labelled the findings “important” did acknowledge the paper was merely observational and could not prove why fluctuating rates may raise the risk of the condition.

Study lead author and expert in chronic disease and ageing at at Monash University in Melbourne, Dr Zhen Zhou, said: “Older people with fluctuating cholesterol levels unrelated to whether they were taking lipid-lowering medications may warrant closer monitoring and proactive preventive interventions”.

Professor Fernando Testai, an expert in neurology and rehabilitation at the University of Illinois Chicago added: “This study adds an important piece to the puzzle of preserving brain health by providing evidence that increasing variability in cholesterol levels is associated with cognitive decline. The study did not include people who started or stopped taking lipid-lowering medications during the study period. So, the results cannot be explained by the effect of statins. From a practical standpoint, not sticking to strategies that improve the lipid profile, such as following a healthy diet and exercising, can worsen the negative impact of harmful lipids on the brain”.

In the study, researchers tracked almost 10,000 adults in their 70s - none of whom made any changes to taking cholesterol-lowering medication.

Over a follow-up of six years, they found 509 participants developed dementia and another 1,760 developed cognitive decline without dementia.

Those with the highest fluctuations in cholesterol - who ranked in the top 25 per cent - were 60% more likely to have a dementia diagnosis, the scientists said. They were also at a 23 per cent higher chance of suffering cognitive decline.

Volunteers with higher levels of low-density lipoprotein cholesterol - LDL cholesterol or "bad" cholesterol - were most likely to see significantly faster declines in cognitive health test scores and tests involving memory and reaction speed. High-density lipoprotein cholesterol (HDL), meanwhile, has long been considered good because of the swathe of evidence showing it protects the heart”.