High cholesterol is associated with a reduced risk of dementia

This study was published in Neurology 2005 May 24;64(10):1689-95

Study title and authors:

High total cholesterol levels in late life associated with a reduced risk of dementia.

Mielke MM, Zandi PP, Sjögren M, Gustafson D, Ostling S, Steen B, Skoog I.

Center on Aging and Health, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA. mmielke@jhsph.edu

This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/15911792

The objective of the study was to examine the association between cholesterol levels and dementia. The study included 392 participants who had their cholesterol levels examined at ages 70, 75 and 79 and were assessed for dementia between the ages of 79 and 88.

The study found:
(a) At age 70, for every 1 mmol/L (38 mg/dL) increase in cholesterol levels there was a 23% decreased risk of dementia between the ages of 79 and 88.
(b) At age 75, for every 1 mmol/L (38 mg/dL) increase in cholesterol levels there was a 30% decreased risk of dementia between the ages of 79 and 88.
(c) At age 79, for every 1 mmol/L (38 mg/dL) increase in cholesterol levels there was a 27% decreased risk of dementia between the ages of 79 and 88.
(d) At age 70, those with the highest cholesterol (8.03 to 11.44 mmol/L or 311 to 442 mg/dL) had a 69% decreased risk of dementia between the ages of 79 and 88.
(e) At age 75, those with the highest cholesterol (7.03 to 9.29 mmol/L or 272 to 359 mg/dL) had a 80% decreased risk of dementia between the ages of 79 and 88.
(f) At age 79, those with the highest cholesterol (6.82 to 9.10 mmol/L or 264 to 352 mg/dL) had a 55% decreased risk of dementia between the ages of 79 and 88.

This study shows that high cholesterol is associated with a reduced risk of dementia.