Reduce your bad cholesterol levels to keep Alzheimer’s, dementia at bay

NEW DELHI: Lowering bad blood cholesterol may not only be good for your heart but is also crucial to prevent Alzheimer’s as well as dementia, according to a study.

The study, published online in the Journal of Neurology Neurosurgery and Psychiatry, revealed that low-density lipoprotein cholesterol (LDL-C), also known as bad cholesterol, below 1.8 mmol/L was associated with a 26 per cent reduction in the risk of all-cause dementia.

It also led to a 28 per cent reduction in the risk of Alzheimer’s disease-related dementia, compared with LDL-C levels above 3.4 millimoles per litre (mmol/L).

Further, researchers from the Hallym University College of Medicine in South Korea explained that statins conveyed an additional protective effect for people with low LDL-C, specifically those with blood levels less than 1.8 mmol/L.

Among people with LDL-C levels below 1.8 mmol/L, statin use was associated with a 13 per cent reduction in all-cause dementia risk and a 12 per cent decrease in risk of Alzheimer’s disease-related dementia compared with non-users.

“Low LDL-C levels (less than 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,” the team said

“These findings underscore the crucial role of managing LDL-C in lowering dementia risk,” they added.

For the study, the team identified 192,213 people with LDL-C levels less than 1.8 mmol/L and 379,006 patients with LDL-C levels more than 3.4 mmol/L and matched individuals in each group into 108,980 matched pairs.

The protective effect against cognitive decline lessened at lower LDL-C levels and eventually disappeared entirely.

At LDL-C levels below 1.4 mmol/L, there was an 18 per cent risk reduction for both all-cause dementia and Alzheimer’s disease-related dementia compared with LDL-C levels above 3.4 mmol/L, and when LDL-C levels fell below 0.8 mmol/L the risk reductions disappeared.

“This is an observational study, and as such, no firm conclusions can be drawn about cause and effect,” said the researchers, while acknowledging limitations such as the focus on baseline LDL-C levels when lipid profiles could change over time.