Alcohol and Alzheimer's Disease—Does Alcohol Dependence Contribute to Beta-Amyloid Deposition, Neuroinflammation and Neurodegeneration in Alzheimer's Disease?

AIMS: To investigate the underlying neurobiology between alcohol use, misuse and dependence and cognitive impairment, particularly Alzheimer's disease (AD). METHODS: Review of the literature using searches of Medline, Pubmed, EMBASE, PsycInfo, and meeting abstracts and presentations. RESULTS: The role of alcohol as a risk factor and contributor for cognitive decline associated with AD has received little attention. This is despite the high prevalence of alcohol use, the potential reversibility of a degree of cognitive impairment and the global burden of AD. Until now the focus has largely been on the toxic effects of alcohol, neuronal loss and the role of thiamine. CONCLUSION: We propose alcohol adds to the cognitive burden seen in dementia through additional mechanisms to neurodegenerative processes or may contribute at various mechanistic points in the genesis and sustenance of AD pathology via neuroinflammation. We describe the common underlying neurobiology in alcohol and AD, and examine ways alcohol likely contributes to neuroinflammation directly via stimulation of Toll-like receptors and indirectly from small bowel changes, hepatic changes, withdrawal and traumatic brain injury to the pathogenesis of AD. SHORT SUMMARY: Alcohol use, misuse and dependence cause cognitive impairment. We propose alcohol adds to the cognitive burden seen in dementia through additional mechanisms to neurodegenerative processes or may contribute at various mechanistic points in the genesis and sustenance of AD pathology via neuroinflammation.