Editing Dementia (section)

===Dental health===
Limited evidence links poor oral health to cognitive decline. However, failure to perform tooth brushing and gingival inflammation can be used as dementia risk predictors.<ref>{{cite journal | vauthors = Daly B, Thompsell A, Sharpling J, Rooney YM, Hillman L, Wanyonyi KL, White S, Gallagher JE | title = Evidence summary: the relationship between oral health and dementia | journal = British Dental Journal | volume = 223 | issue = 11 | pages = 846–853 | date = January 2018 | pmid = 29192686 | doi = 10.1038/sj.bdj.2017.992 | s2cid = 19633523 | url = https://researchportal.port.ac.uk/portal/files/8739213/Evidence_summary_the_relationship_between_oral_health_and_dementia_post_print.pdf }}</ref>

====Oral bacteria====
There is some evidence that oral bacteria in people with gum disease may be a link to declines in cognitive health.<ref name="Miklossy">{{cite journal | vauthors = Miklossy J | title = Historic evidence to support a causal relationship between spirochetal infections and Alzheimer's disease | journal = Frontiers in Aging Neuroscience | volume = 7 | page = 46 | date = 2015 | pmid = 25932012 | pmc = 4399390 | doi = 10.3389/fnagi.2015.00046 | doi-access = free }}</ref> The proposed mechanism is still being studied, but research has linked specific types of bacteria in the mouth to those found in some people's brain who have Alzheimer's disease. There is also some evidence that people with a high level of tooth plaque are also at a greater risk of cognitive decline.<ref name="BDJ_2017">{{cite journal | vauthors = | title = Can poor oral health lead to dementia? | journal = British Dental Journal | volume = 223 | issue = 11 | page = 840 | date = December 2017 | pmid = 29243693 | doi = 10.1038/sj.bdj.2017.1064 | s2cid = 25898592 }}</ref> Poor oral hygiene can have an adverse effect on speech and nutrition, causing general and cognitive health decline.{{Citation needed|date=April 2025}}

====Oral viruses====
[[Herpes simplex virus]] (HSV) has been found in more than 70% of those aged over 50. HSV persists in the peripheral nervous system and can be triggered by stress, illness or fatigue.<ref name = "Olsen_2015">{{cite journal | vauthors = Olsen I, Singhrao SK | title = Can oral infection be a risk factor for Alzheimer's disease? | journal = Journal of Oral Microbiology | volume = 7 | page = 29143 | date = September 17, 2015 | pmid = 26385886 | pmc = 4575419 | doi = 10.3402/jom.v7.29143 }}</ref> High proportions of viral-associated proteins in [[amyloid plaques]] or [[neurofibrillary tangle]]s (NFTs) confirm the involvement of HSV-1 in Alzheimer's disease pathology. NFTs are known as the primary marker of Alzheimer's disease. HSV-1 produces the main components of NFTs.<ref>{{cite journal | vauthors = Carter CJ | title = Alzheimer's disease plaques and tangles: cemeteries of a pyrrhic victory of the immune defence network against herpes simplex infection at the expense of complement and inflammation-mediated neuronal destruction | journal = Neurochemistry International | volume = 58 | issue = 3 | pages = 301–320 | date = February 2011 | pmid = 21167244 | doi = 10.1016/j.neuint.2010.12.003 | s2cid = 715832 }}</ref>