It’s not unexpected that having high cholesterol is related to developing dementia. What may be more surprising is that large swings in cholesterol over time are a large factor in increasing the risk of dementia- more so than having a somewhat higher cholesterol level that is stable over time. The most affected cognitive decline components were global cognition, episodic memory, and psychomotor speed (how fast someone can process information and react to stimuli).
A recent Australian study that followed people over 5 years found that those with the largest fluctuations were 60% more likely to develop dementia than those with the lowest fluctuations. The correlations with developing dementia were more significant for variations in levels of LDL (low-density lipoprotein cholesterol) than for triglycerides, which was associated only with a risk for developing cognitive decline. Further, fluctuations in HDL (high-density lipoprotein) cholesterol had no correlation with the risk of developing cognitive impairment or dementia.
The importance of this study is that the results may change the way risk factors for dementia are monitored. In terms of cholesterol level, following the trend of cholesterol levels measured yearly would be more effective than measuring cholesterol levels at a single point in time. The study suggested that the association between cholesterol variations and dementia risk was greatest in patients with a family history of dementia and with a genetic predisposition (APOE-ε4 carriers).
The study does not define the basis of causality in the risk of fluctuations of cholesterol levels. Rather than affecting the deposition of amyloid and tau in the brain, the fluctuations may be damaging vessels in the brain, in particular the atherosclerotic plaques. Perhaps the increase risk conferred by variations in cholesterol is due to the additional brain burden of microvascular disease to the amyloid plaques.
BeCareLink can help to track cognitive decline and empower you to monitor your progress as you take steps to reduce your risk of developing dementia.
Reference: https://www.medscape.com/viewarticle/fluctuating-cholesterol-levels-tied-dementia-cognitive-2025a10003ho?ecd=WNL_trdalrt_pos1_250215_etid7233196&uac=152547CG&impID=7233196F