{"id":468035,"date":"2026-02-14T10:26:13","date_gmt":"2026-02-14T10:26:13","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/468035\/"},"modified":"2026-02-14T10:26:13","modified_gmt":"2026-02-14T10:26:13","slug":"one-in-three-dementia-cases-is-linked-to-disease-outside-the-brain-sciencealert","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/468035\/","title":{"rendered":"One in Three Dementia Cases Is Linked to Disease Outside The Brain : ScienceAlert"},"content":{"rendered":"<p>Some forms of dementia may not be confined to the central nervous system; they may not even begin in the brain.<\/p>\n<p>A systematic review of more than 200 studies has now found that as many as a third of all dementia cases are tied to diseases outside the brain.<\/p>\n<p>That&#8217;s nearly <a href=\"https:\/\/www.who.int\/news-room\/fact-sheets\/detail\/dementia\" rel=\"nofollow noopener\" target=\"_blank\">19 million dementia cases<\/a> globally.<\/p>\n<p>The findings join growing evidence that suggests there are <a href=\"https:\/\/www.sciencealert.com\/scientists-have-identified-four-distinct-types-of-alzheimer-s\" rel=\"nofollow noopener\" target=\"_blank\">many distinct subtypes<\/a> of dementia and <a href=\"https:\/\/www.sciencealert.com\/alzheimers-might-not-actually-be-a-brain-disease-reveals-expert\" rel=\"nofollow noopener\" target=\"_blank\">not all of them<\/a> necessarily originate in the brain.<\/p>\n<p>There&#8217;s a chance that some peripheral diseases are actually playing a role in cognitive decline.<\/p>\n<p>The recent global review, led by scientists at Sun Yat-sen University in China, identified as many as 16 culprits using data from all over the world.<\/p>\n<p>The top five peripheral diseases that most strongly correlated with increased dementia risk were <a href=\"https:\/\/www.sciencealert.com\/study-links-gum-disease-with-white-matter-damage-in-the-brain\" rel=\"nofollow noopener\" target=\"_blank\">gum disease<\/a>, chronic liver diseases, <a href=\"https:\/\/www.sciencealert.com\/cant-hear-people-when-its-noisy-a-study-links-this-to-dementia-risk\" rel=\"nofollow noopener\" target=\"_blank\">hearing loss<\/a>, <a href=\"https:\/\/www.sciencealert.com\/your-vision-can-predict-dementia-12-years-before-a-diagnosis-research-suggests\" rel=\"nofollow noopener\" target=\"_blank\">vision loss<\/a>, and type 2  <a href=\"https:\/\/www.sciencealert.com\/diabetes\" class=\"lar_link lar_link_outgoing\" data-linkid=\"73018\" data-postid=\"191386\" rel=\"nofollow noopener\" target=\"_self\">diabetes<\/a>.<\/p>\n<p>Slightly weaker correlations were observed for <a href=\"https:\/\/www.sciencealert.com\/osteoarthritis-is-appearing-in-younger-adults-triggering-decades-of-discomfort\" target=\"_blank\" rel=\"noopener nofollow\">osteoarthritis<\/a>, <a href=\"https:\/\/www.sciencealert.com\/these-7-common-daily-habits-could-be-damaging-your-kidneys\" target=\"_blank\" rel=\"noopener nofollow\">kidney<\/a> disease, cardiovascular disease, <a href=\"https:\/\/www.mayoclinic.org\/diseases-conditions\/copd\/symptoms-causes\/syc-20353679\" target=\"_blank\" rel=\"noopener nofollow\">chronic obstructive pulmonary disease<\/a> (COPD), and immune-mediated inflammatory diseases, like <a href=\"https:\/\/www.sciencealert.com\/multiple-sclerosis-may-have-two-distinct-subtypes-scientists-discover\" rel=\"nofollow noopener\" target=\"_blank\">multiple sclerosis<\/a> and <a href=\"https:\/\/www.sciencealert.com\/a-crucial-genetic-mutation-behind-crohns-disease-has-finally-been-revealed\" rel=\"nofollow noopener\" target=\"_blank\">inflammatory bowel disease<\/a>.<\/p>\n<p>The review does not prove causality; however, the authors <a href=\"https:\/\/doi.org\/10.1038\/s41562-025-02392-2\" rel=\"nofollow noopener\" target=\"_blank\">say<\/a> that their findings &#8220;indicate the potential to mitigate dementia incidence by proactive prevention of peripheral diseases.&#8221;<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/02\/PeripheralDiseaseDementia-642x335.png\" alt=\"Peripheral Disease Dementia\" width=\"642\" height=\"335\" class=\"size-medium wp-image-191400\"   loading=\"lazy\"\/>Temporal trends in cases of dementia from 1990 to 2021 (c) and variations across age groups (f). Dark blue = audiovisual disorders; green = periodontal diseases; pink = cirrhosis and chronic liver diseases; light blue = type 2 diabetes; purple = chronic kidney disease; red = osteoarthritis; light grey = COPD; dark grey = immune-mediated inflammatory diseases.<\/p>\n<p>Recently, studies have found that dementia is closely tied to a whole host of peripheral health issues, including <a href=\"https:\/\/www.sciencealert.com\/blood-sugar-spikes-linked-with-69-higher-risk-of-alzheimers\" rel=\"nofollow noopener\" target=\"_blank\">blood sugar spikes<\/a>, <a href=\"https:\/\/www.sciencealert.com\/10-key-reasons-dementia-is-linked-with-diabetes\" rel=\"nofollow noopener\" target=\"_blank\">type 2 diabetes<\/a>, <a href=\"https:\/\/www.sciencealert.com\/6-things-gen-z-should-be-doing-right-now-to-stave-off-dementia-later\" rel=\"nofollow noopener\" target=\"_blank\">hearing loss<\/a>, <a href=\"https:\/\/www.sciencealert.com\/a-sign-deep-inside-your-eyes-could-warn-of-early-dementia\" rel=\"nofollow noopener\" target=\"_blank\">vision issues<\/a>, <a href=\"https:\/\/www.sciencealert.com\/gut-inflammation-link-to-alzheimers-disease-confirmed-once-again\" rel=\"nofollow noopener\" target=\"_blank\">gut inflammation<\/a>, and <a href=\"https:\/\/www.sciencealert.com\/the-cause-of-alzheimers-may-be-coming-from-within-your-mouth\" rel=\"nofollow noopener\" target=\"_blank\">gum disease<\/a>.<\/p>\n<p>Initial research even suggests that <a href=\"https:\/\/www.sciencealert.com\/landmark-trial-suggests-hearing-aids-help-reduce-cognitive-decline\" rel=\"nofollow noopener\" target=\"_blank\">hearing aids<\/a> may help <a href=\"https:\/\/www.sciencealert.com\/hearing-aids-may-help-you-avoid-dementia-study-finds\" rel=\"nofollow noopener\" target=\"_blank\">prevent dementia<\/a>, and treating liver cirrhosis <a href=\"https:\/\/www.sciencealert.com\/up-to-13-of-dementia-diagnoses-may-actually-be-a-treatable-condition\" rel=\"nofollow noopener\" target=\"_blank\">might help patients avoid<\/a> cognitive decline.<\/p>\n<p>Some <a href=\"https:\/\/www.sciencealert.com\/type-2-diabetes-drug-linked-to-35-lower-dementia-risk-in-patients\" rel=\"nofollow noopener\" target=\"_blank\">drugs for diabetes<\/a> or <a href=\"https:\/\/www.sciencealert.com\/these-two-existing-drugs-may-boost-brain-health-scientists-say\" rel=\"nofollow noopener\" target=\"_blank\">insulin issues<\/a> have even shown they can <a href=\"https:\/\/www.sciencealert.com\/after-60-years-diabetes-drug-found-to-unexpectedly-impact-the-brain\" rel=\"nofollow noopener\" target=\"_blank\">unexpectedly impact<\/a> the brain, potentially boosting cognitive health.<\/p>\n<p><a href=\"https:\/\/www.sciencealert.com\/newsletter?utm_source=promo_octopus_black\" rel=\"nofollow noopener\" target=\"_blank\"><img decoding=\"async\" src=\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/02\/Octopus-black-final-642x272.jpg\" alt=\"Subscribe to ScienceAlert's free fact-checked newsletter\" width=\"642\" height=\"272\" class=\"alignnone wp-image-190933 size-medium\"   loading=\"lazy\"\/><\/a><\/p>\n<p>Scientists aren&#8217;t fully sure why dementia is linked to these other peripheral health issues, or why treating one may help the other, but they are keen to learn more.<\/p>\n<p>Even though the brain is kept in a sort of protected <a href=\"https:\/\/www.sciencealert.com\/scientists-think-theyre-on-the-verge-of-breaching-the-blood-brain-barrier\" rel=\"nofollow noopener\" target=\"_blank\">&#8216;ivory tower&#8217;<\/a>, largely isolated from the rest of the body, it is still connected to peripheral organs in crucial ways, many of which we are just beginning to understand.<\/p>\n<p>Given the <a href=\"https:\/\/www.sciencealert.com\/hidden-rhythms-in-your-brain-and-gut-share-a-surprising-link\" rel=\"nofollow noopener\" target=\"_blank\">brain-gut axis<\/a>, <a href=\"https:\/\/www.sciencealert.com\/brain-bone-axis-may-link-depression-with-osteoporosis-study-claims\" rel=\"nofollow noopener\" target=\"_blank\">the brain-bone axis<\/a>, <a href=\"https:\/\/www.sciencealert.com\/the-mere-thought-of-being-hungry-could-alter-your-immune-system\" rel=\"nofollow noopener\" target=\"_blank\">the brain-immune axis<\/a>, and the brain&#8217;s connections to the liver, heart, kidneys, skin, fat, lymphs, and muscles, it&#8217;s harder than ever for neuroscientists to stay in just one lane.<\/p>\n<p>The recent systematic review from China initially included 26 common peripheral diseases, all of which have been associated with higher dementia risk in the scientific literature.<\/p>\n<p>According to meta-analyses, only 10 of those peripheral diseases lacked a significant link to dementia risk in the current systematic review, including hypertension, obesity, high cholesterol,  <a href=\"https:\/\/www.sciencealert.com\/depression\" class=\"lar_link lar_link_outgoing\" data-linkid=\"73097\" data-postid=\"191386\" rel=\"nofollow noopener\" target=\"_self\">depression<\/a>, and thyroid disease.<\/p>\n<p>Related: <a href=\"https:\/\/www.sciencealert.com\/a-single-molecule-may-explain-how-blood-flow-in-the-brain-triggers-dementia\" rel=\"nofollow noopener\" target=\"_blank\">A Single Molecule May Explain How Blood Flow in The Brain Triggers Dementia<\/a><\/p>\n<p>&#8220;Overall, these insights illustrate the multidimensional burden of dementia related to a wide range of peripheral diseases at the population level,&#8221; <a href=\"https:\/\/doi.org\/10.1038\/s41562-025-02392-2\" rel=\"nofollow noopener\" target=\"_blank\">write<\/a> the review authors, &#8220;highlighting the potential role of peripheral organ function in brain health and the possibility to target those influential peripheral diseases to mitigate the growing dementia burden.&#8221;<\/p>\n<p>If that turns out to be true, then it may explain why so far, many dementia treatments focused on reducing markers of disease in the brain have failed in  <a href=\"https:\/\/www.sciencealert.com\/clinical-trials\" class=\"lar_link lar_link_outgoing\" data-linkid=\"73032\" data-postid=\"191386\" rel=\"nofollow noopener\" target=\"_self\">clinical trials<\/a>.<\/p>\n<p>Perhaps the assumption that cognitive decline starts in the brain has led drug researchers to focus on the wrong targets.<\/p>\n<p>In 2022, neuroscientist Donald Weaver from the University of Toronto in Canada <a href=\"https:\/\/www.sciencealert.com\/alzheimers-might-not-actually-be-a-brain-disease-reveals-expert\" rel=\"nofollow noopener\" target=\"_blank\">wrote<\/a> a piece for The Conversation about how his lab, among others, was focused on a new theory of  <a href=\"https:\/\/www.sciencealert.com\/go\/IaO\" class=\"lar_link lar_link_outgoing\" data-linkid=\"73015\" data-postid=\"191386\" rel=\"nofollow noopener\" target=\"_self\">Alzheimer&#8217;s<\/a>, which characterizes the disease as an immunological disorder at its core.<\/p>\n<p>The immune system is found in every organ in the body, which means that if it were to fail for whatever reason, its impact on the body would be immense and diverse, much like the symptoms of dementia.<\/p>\n<p><a href=\"https:\/\/doi.org\/10.1016\/j.mito.2022.05.001\" rel=\"nofollow noopener\" target=\"_blank\">Other scientists<\/a> have also suggested that dementia stems from a metabolic issue, caused by faulty energy production within cells, leading to widespread problems.<\/p>\n<p>Even if dementia does start in the central nervous system, to define it solely as a neurological disease seems to miss a big part of the picture.<\/p>\n<p>No brain is an island.<\/p>\n<p>The study was published in <a href=\"https:\/\/doi.org\/10.1038\/s41562-025-02392-2\" style=\"letter-spacing: -0.025em;\" rel=\"nofollow noopener\" target=\"_blank\">Nature Human Behavior<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"Some forms of dementia may not be confined to the central nervous system; they may not even begin&hellip;\n","protected":false},"author":2,"featured_media":468036,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[34],"tags":[97,1352],"class_list":["post-468035","post","type-post","status-publish","format-standard","has-post-thumbnail","category-health","tag-health","tag-msft-content"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/468035","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=468035"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/468035\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/468036"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=468035"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=468035"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=468035"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}