Low cholesterol levels may be associated with the development of dementia

This study was published in the Archives of Neurology 2007 Jan;64(1):103-7

Study title and authors:
Twenty-six-year change in total cholesterol levels and incident dementia: the Honolulu-Asia Aging Study.

Stewart R, White LR, Xue QL, Launer LJ.
King's College London (Institute of Psychiatry), Section of Epidemiology, England. r.stewart@iop.kcl.ac.uk

This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/17210816

This study investigated the relationship between cholesterol levels and the risk of dementia. The study included 1,027 men who were followed for 26 years. Over the course of the study the men had their cholesterol levels measured on five occasions and were screened for dementia on two occasions.

The study found that  cholesterol levels in men with dementia and, in particular, those with Alzheimer disease had declined at least 15 years before the diagnosis and remained lower than cholesterol levels in men without dementia throughout that period.

Stewart concluded: "A decline in serum total cholesterol levels may be associated with early stages in the development of dementia".

Review finds that low cholesterol levels are linked to higher rates of early death, suicide, aggressive and violent behaviour, personality disorders, depression and dementia

This paper was published in Revista de Neurologia 2009 Mar 1-15;48(5):261-4

 

Study title and authors:

Relation between cholesterol levels and neuropsychiatric disorders

Martínez-Carpio PA, Barba J, Bedoya-Del Campillo A.

Centro Penitenciario de Jóvenes de Barcelona, Generalitat de Catalunya, Sant Joan de Déu, Barcelona, España. pmc@investilaser.com

 

This paper can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/19263395

The researchers conducted a systematic study of the literature that addressed the relationship between low cholesterol levels and neuropsychiatric disorders.

They found that low cholesterol levels are associated and related to different neuropsychiatric disorders. Lowered cholesterol levels seem likely to be linked to higher rates of early death, suicide, aggressive and violent behaviour, personality disorders, and possibly depression, dementia and penal confinement among young males.

Higher levels of cholesterol are associated with a decreased risk of Alzheimer's Disease

This study was published in the Archives of Neurology 2004 May;61(5):705-14

Study title and authors:
Relation of plasma lipids to Alzheimer disease and vascular dementia.

Reitz C, Tang MX, Luchsinger J, Mayeux R.
Gertrude H. Sergievsky Center, Columbia University College of Physicians and Surgeons, New York, NY, USA.

This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/15148148

This study investigated the relationship between cholesterol levels and Alzheimer disease and vascular dementia. (Vascular dementia is caused by problems in the supply of blood to the brain usually from a stroke). The study included 4,316 participants aged 65 years and older.

The study found:
(a) The risk of prevalent Alzheimer's was 28% higher in those who had low cholesterol, under 172 mg/gL (4.4 mmol/L), compared to those with cholesterol levels between 197-225 mg/dL (5.1-5.8 mmol/L).
(b) The risk of prevalent Alzheimer's was 34% higher in those who had low levels of high density lipoprotein (HDL) cholesterol, under 37 mg/gL (.95 mmol/L), compared to those with high density lipoprotein (HDL) cholesterol levels over 55 mg/dL (1.4 mmol/L).
(c) The risk of prevalent vascular dementia was 20% higher in those who had low cholesterol, under 172 mg/gL (4.4 mmol/L), compared to those with cholesterol levels between 197-225 mg/dL (5.1-5.8 mmol/L).
(d) The risk of prevalent vascular dementia was 40% higher in those who had low levels of high density lipoprotein (HDL) cholesterol, under 37 mg/gL (.95 mmol/L), compared to those with high density lipoprotein (HDL) cholesterol levels over 55 mg/dL (1.4 mmol/L).

The lead author of the study Dr Christiane Reitz commented: "Our results do not support the hypothesis that the risk of Alzheimer's Disease is associated with plasma lipid levels. They also do not support the hypothesis that statin use is associated with a lower risk of Alzheimer's Disease."

Dr Reitz is a medical doctor and genetic epidemiologist. Her research focuses on the identification of genetic and non-genetic factors that contribute to Alzheimer's disease, frontotemporal lobar degeneration, and structural and functional brain changes.

Dr Reitz concluded: "Higher levels of total cholesterol were associated with a decreased risk of incident Alzheimer's Disease."

Higher saturated fat and cholesterol consumption is associated with a lower risk of dementia

This study was published in Neurology 2002 Dec 24;59(12):1915-21

 

Study title and authors:

Diet and risk of dementia: Does fat matter?: The Rotterdam Study.

Engelhart MJ, Geerlings MI, Ruitenberg A, Van Swieten JC, Hofman A, Witteman JC, Breteler MM.

Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.

 

This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/12499483

The objective of the study was to examine whether intake of fats are associated with the risk of dementia. The dietary habits of 5,395 subjects with normal cognition were assessed over a six year period.

The study found:
(a) Higher fat consumption was associated with a 7% reduction in dementia.
(b) Higher saturated fat consumption was associated with a 9% reduction in dementia.
(c) Higher cholesterol consumption was associated with a 7% reduction in dementia.
(d) Higher polyunsaturated fat consumption was associated with a 5% increase in dementia.

The data from the study reveals that higher saturated fat and cholesterol consumption is associated with a lower risk of dementia.

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.

Low cholesterol levels are associated with higher rates of dementia

This study was published in the Journals of Gerontology. Series A, Biological Sciences and Medical Sciences 2010 May;65(5):559-64

Study title and authors:
Relationship between low levels of high-density lipoprotein cholesterol and dementia in the elderly. The InChianti study.

Zuliani G, Cavalieri M, Galvani M, Volpato S, Cherubini A, Bandinelli S, Corsi AM, Lauretani F, Guralnik JM, Fellin R, Ferrucci L.
Department of Clinical and Experimental Medicine, Section of Internal Medicine, Gerontology and Geriatrics, University of Ferrara, Via Savonarola 9, 44100 Ferrara, Italy. gzuliani@hotmail.com

This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/20299544

The object of the study was to evaluate the association between cholesterol levels and the prevalence of dementia. At the start of the study a total of 1,051 individuals aged 65 years or over were assessed for dementia and again after three years.

The study found:
(a) After one year, individuals with dementia had significantly lower cholesterol levels and significantly lower levels of  high-density lipoprotein (HDL) cholesterol compared with individuals without dementia.
(b) After three years, individuals newly diagnosed with dementia had significantly lower cholesterol levels and significantly lower levels of high-density lipoprotein (HDL) cholesterol compared with individuals without dementia.

The results of the study demonstrate that low cholesterol levels and low levels of HDL cholesterol are associated with higher rates of dementia.