Positively! They are related. By time untreated high cholesterol can cause thickening of artery wall and affect the blood supply to the brain.
Studies proved that high cholesterol levels at midlife (>240 mg/dl) represented a significant risk factor for Alzheimer’s disease and vascular dementia, besides the well-familiar link to cardiovascular disease risk. Even moderately elevated cholesterol increased dementia risk. 1, 2, 3
In an attempt to explain the reason behind it, high cholesterol levels increase the production of plaques. Cholesterol might also act as a promoter for clusters of a specific protein to form in the brain. This protein is well known to be a key causative factor for Alzheimer's disease, when protein particles combine, they also form plaques that are toxic to brain function and kills off brain cells.1, 4
Consequently, to reduce your risk of dementia, stroke and heart disease regularly check your cholesterol and make sure to comply with treatment schedule.1
1. Cholesterol: High cholesterol in midlife increases the risk of dementia. Your Brain Matters. Available at: https://yourbrainmatters.org.au/brain_health/evidence/cholesterol Last accessed: 24/06/2019
2. Cholesterol and dementia. Alzheimer's Society. Available at: https://www.alzheimers.org.uk/about-dementia/risk-factors-and-prevention/cholesterol-and-dementia Last accessed: 25/06/2019
3. Solomon, A.Midlife Serum Cholesterol and Increased Risk of Alzheimer’s and Vascular Dementia Three Decades Later, Dement Geriatr Cogn Disord 2009; 28: 75–80.
4. Wanamaker, B. Cholesterol, Statins, and Dementia: What the Cardiologist Should KnowClin Cardiol. 2015 April ; 38(4): 243–250