The connection between scent and Alzheimer\u2019s has been theorized for years, but the study\u2019s findings are a promising sign that neurologists may start testing the sensitivity of smell in patients, Dr. Dale Bredesen, a neurologist at Apollo Health<\/a> with a focus on Alzheimer\u2019s disease, told HuffPost. <\/p>\n \u201cThe question has always been, \u2018Why is [smell loss] such an early change in Alzheimer\u2019s?\u2019\u201d Bredesen said. \u201cI think this [study] will help to let neurologists know we should be more sensitively testing smell in people routinely before they ever have any cognitive complaints.\u201d<\/p>\n One of the earliest sites degenerated in Alzheimer\u2019s disease is called the locus coeruleus, which is a spot in the brain stem that provides the brain with norepinephrine, Bredesen explained. Norepinephrine helps regulate functions like smell, sleep and blood flow. <\/p>\n The research team used mouse models, human brain tissue from deceased patients and PET brain scans from living Alzheimer\u2019s patients to try to figure out how and why Alzheimer\u2019s disease is linked to smell. <\/p>\n They found that Alzheimer\u2019s triggers abnormal neuron firing, which causes phosphatidylserine \u2014 a molecule normally found on the inside of neuron membranes \u2014 to shift to the outside. This shift essentially tricks microglia into thinking that the fibers are issuing out an \u201ceat-me\u201d signal and need to be removed. The microglia attack the fibers connecting the locus coeruleus to the olfactory bulb, the neural structure in the forebrain that controls the sense of smell, which is why smell loss is one of the first features to deteriorate. <\/p>\n \u201c[The study] brings this all together and shows that the locus coeruleus damage, the loss of sense of smell \u2026 is probably related to energy,\u201d Bredesen said, based on his own expertise in the field. \u201cSo the new insight says, \u2018Hey neurologists, please, look more carefully and more quantitatively at the sense of smell because this can be another of the early warning signs.\u2019\u201d<\/p>\n If you\u2019re at risk for Alzheimer\u2019s, experts recommend asking for a smell test.<\/p>\n Current Alzheimer\u2019s treatments, like amyloid-beta antibodies, have been found to work best when given to patients as early as possible. If smell tests could help flag at-risk patients years ahead of their memory loss symptoms, neurologists could potentially slow the disease\u2019s progression. <\/p>\n \u201cWith all these complex chronic illnesses, things are changing when you can pick them up earlier and do something about it,\u201d Bredesen said. <\/p>\n Bredesen compared it to the hemoglobin A1C<\/a>, which came out 50 years ago and has changed the landscape of pre-diabetes diagnoses, and biomarkers like the P-tau217,<\/a> which can help identify potential Alzheimer\u2019s patients over 20 years before the onset of symptoms. <\/p>\n This is also \u201cessentially what happened with Pap smears many, many years ago,\u201d he said, referring to the potential of these smell tests. \u201cYou went from a disease where you would find it late, and women would die from it.\u201d (While cervical cancer remains a significant health threat, it is now a highly preventable and curable condition when found early, and deaths have dropped over 50%<\/a> since the 1970s due to Pap smears.) <\/p>\n Bredesen insists that anyone over the age of 35 who has a family history of brain cognitive conditions could ask their neurologist to have their sense of smell tested. Lifestyle factors \u2015 like exercise, eating nutritious foods and social interactions \u2015 remain an important part of prevention as well.<\/p>\n And, most importantly, know that a smell test is not a guaranteed answer for at-risk patients. Bredesen emphasized that studies like this one are shifting neurologists and doctors in the right direction, but anyone at risk of Alzheimer\u2019s should not assume that if they pass a smell test, they\u2019re 100% in the clear. <\/p>\n \u201cIf you start noticing some decrease in your smelling ability, please get to a doctor,\u201d he said. \u201cDon\u2019t assume that it\u2019s a benign condition.\u201d <\/p>\n","protected":false},"excerpt":{"rendered":"A new study has found that the loss of smell could be an early warning sign of Alzheimer\u2019s…\n","protected":false},"author":2,"featured_media":584173,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[34],"tags":[42938,1103,97],"class_list":["post-584172","post","type-post","status-publish","format-standard","has-post-thumbnail","category-health","tag-alzheimer","tag-dementia","tag-health"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/584172","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=584172"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/584172\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/584173"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=584172"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=584172"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=584172"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Researchers](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/04\/69dd216218000068eea15cf2.jpeg\")
Researchers discovered that loss of smell could be an early signal of Alzheimer’s disease.<\/p>\n