Alzheimer’s disease could begin in the nose long before patients experience any traditional symptoms of memory loss, according to new research highlighted by mathematician and Celebrity Traitors star, Professor Hannah Fry.
Professor Fry, whose father passed away from Alzheimer’s in 2025, is drawing attention to a groundbreaking scientific theory suggesting that the disease’s origins are far more external than previously understood. Speaking in a video for New Scientist, she explained that while the brain is typically “locked away” within the skull for protection, there is one significant vulnerability: the olfactory system.
“One of the few areas where the brain has a connection to the outside is through your nose,” Professor Fry said. She noted that the area behind the nose contains tiny holes in the skull through which olfactory nerves pass, effectively providing a direct, physical route into the brain.
The theory centers on the idea that foreign particles, bacteria, or pollutants could enter the body through the nose and travel directly to the brain, triggering the characteristic inflammation and plaque build-up associated with Alzheimer’s.
Evidence for this “nasal pathway” hypothesis has emerged from a variety of studies involving both animal and human subjects. In one notable experiment, scientists introduced a specific strain of bacteria—Chlamydia pneumoniae—into the noses of mice. Within 72 hours, the infection had bypassed the blood-brain barrier and moved into the brain, causing an inflammatory response and the formation of plaques identical to those seen in Alzheimer’s patients.
Further research has examined the impact of environmental factors. Studies of stray dogs living in highly polluted Mexican cities revealed “tiny little flecks of metals” embedded within their brain tissue. Each of these metal fragments was found to be surrounded by the same toxic plaques and inflammatory responses characteristic of the disease.
This trend has recently been observed in humans as well. Investigations into children and adults raised in heavily polluted environments have identified similar patterns of brain matter reaction. It is hypothesized that the brain may be attempting to fight off environmental toxins that have been “sniffed up,” but the resulting defensive response ultimately leads to the neurological damage associated with dementia.
Given these findings, experts are now investigating whether a gradual loss of smell could serve as a vital early warning sign of Alzheimer’s, occurring years or even decades before cognitive decline manifests.
As Alzheimer’s remains the most common cause of dementia in the UK, this shift in research focus could prove transformative. By looking beyond the brain and toward the environment and the olfactory system, scientists hope to better understand the early-stage triggers of the disease, potentially opening new doors for preventative care and early intervention.
Disclaimer: This content is auto-generated for informational purposes only.
Source: Read Original News
