Reduced levels of high-density lipoproteins (HDL) in middle age could raise the risk of memory loss and dementia in later life, new research suggests.

A study reported in the Arteriosclerosis, Thrombosis and Vascular Biology: Journal of the American Heart Association found that low levels of HDL cholesterol may be used as a predictor of neurodegenerative risk - particularly memory loss - in patients by the time they reach the age of 60.

Lead author of the report Dr Archana Singh-Manoux, senior research fellow with the French National Institute for Health and Medical Research (INSERM, France) and the University College London, commented: "Memory problems are key in the diagnosis of dementia."

The research, which involved 3,673 participants, revealed that at age 55 patients with low HDL cholesterol were 27 per cent more likely to suffer from memory loss than those with high levels of HDL.

At the age of 60, participants with low HDL had a 53 per cent increased risk of memory loss compared to the group of patients with high levels of good cholesterol.

The findings demonstrate that high levels of HDL help reduce formation of beta-amyloid in the protein plaques associated with Alzheimer's disease.

Dr Singh-Manoux concluded: "Many previous investigations into the association between lipids and memory in the elderly have focused on total or LDL cholesterol because of their status as proven risk factors for cardiovascular disease.

Our results show HDL cholesterol to be important for memory. Thus, physicians and patients should be encouraged to monitor levels of HDL cholesterol."

Statistics show that neurodegenerative diseases such as Alzheimer's, most commonly affect people over the age of 65.

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