In April 2012, a unique question arose during a lecture on Parkinson's disease in Edinburgh. A nurse named Joy Mill asked if anyone had ever researched whether people with Parkinson's actually gave off a different smell, not just experiencing a loss of their own sense of smell. This question piqued the curiosity of the scientists present and ignited a new line of investigation.

Initially skeptical, researchers decided to test whether Joy’s observations had any scientific merit. They designed a controlled experiment in which Joy attempted to identify individuals with Parkinson's by sniffing their t-shirts, a process that yielded surprising results and spurred further study into the underlying causes and implications of this phenomenon.

Key Takeaways

A nurse raised the idea that Parkinson’s sufferers might emit a distinctive odor.
Researchers conducted controlled experiments to test this claim.
The findings prompted deeper investigation despite skepticism in the scientific community.

Identification of a Distinct Parkinson's Indicator

Joy Milne's Remarkable Scent Detection

Joy Milne, a nurse with an unusually keen sense of smell, noticed a significant change in her husband’s body odor after he developed Parkinson’s disease. She described this new scent as notably less pleasant than his previous, natural aroma. This personal observation led her to wonder if others with Parkinson’s experienced a similar change.

Milne approached experts, insisting that the alteration was not related to the commonly reported loss of smell among patients, but rather to an actual shift in their body odor. Her persistent conviction that the disease affected scent highlighted a potential new symptom previously unrecognized by the medical community.

Person Role Observation Joy Milne Nurse/Wife Detected odor change in spouse Les Milne Parkinson's Patient Scent changed after diagnosis

Early Responses from Professor Kunath

When first confronted with Milne’s query during a lecture, Professor Tilo Kunath initially misunderstood, assuming she referred to patients’ impaired sense of smell. Upon realizing she meant the emergence of a distinctive odor, he admitted the idea was completely novel to him.

Kunath did not dismiss her theory outright, despite its unusual nature. Instead, her professional manner and strong assurance made an impression, prompting him to recall the encounter and eventually pursue further investigation alongside colleagues.

Key Points:

Initial skepticism stemmed from the unconventional claim.
Milne’s background and demeanor lent credibility.
The possibility of a genuine, measurable scent change became an intriguing avenue for study.

Exploring the Possibility of Smelling Parkinson’s

Evidence Supporting Smell-Based Disease Detection

An event at a medical conference prompted a serious look into the idea that Parkinson's might change a person's scent. A nurse, Joy, reported that her husband’s smell had altered after he developed the condition. This claim stood out, as loss of smell is a known symptom, but changes in how a person smells to others had rarely been discussed.

Dog Scent Comparisons:
There is precedent for animals, especially dogs, detecting illness by scent. Dogs can identify certain cancers, and while their noses are much more sensitive than humans’ — for reference, a Bloodhound’s sense of smell is up to 100 million times better — the hypothesis wasn't dismissed outright.
Double-Blind Testing:
To test Joy’s claim, scientists organized an experiment:
Group Number of Participants Test Clothing Parkinson’s Group 6 White T-shirts Control Group 6 White T-shirts
Participants wore clean white t-shirts for 24 hours, avoiding perfumes or deodorants. The t-shirts were then cut in half, bagged, and evaluated by Joy, who relied solely on her sense of smell to identify Parkinson’s cases.
Joy accurately identified all six Parkinson’s samples, also matching each shirt half, with one false positive. Although the sample size was small, the high accuracy rate prompted further curiosity about what exactly caused the scent.

Discussions with Chemical Analysis Expert Perdita Barran

Afterward, the attention turned to the chemical cause behind the suspected smell. At first, scientists suspected sweat. However, Joy noted that the scent was strongest near the neckline and upper back, not underarms. This observation shifted the focus toward sebum, the natural oil from sebaceous glands.

Research Steps:
- Sample Collection: Scientists aimed to collect and analyze sebum from both Parkinson’s sufferers and control subjects.
- Funding Difficulties: Despite promising initial results, securing financial support proved challenging. The scientific community was hesitant, especially given the limited test runs and a single mistake in Joy’s closest sniff test.
The project faced delays and was ultimately paused, largely because of skepticism around basing research on an unusual human ability and the lack of large-scale evidence at that time.

Key Points:

Human and animal scent detection skills are very different, but not entirely incomparable.
Initial testing suggested that something in bodily oils, not sweat, might produce the detectable scent.
Efforts to further investigate the source were hindered by funding and doubt from the broader scientific community.

The Double-Blind Smell Identification Experiment

Selection and Preparation of Volunteers

A group of twelve individuals were chosen for this test: six had been diagnosed with Parkinson's disease and six had not. Each person was provided with a fresh white T-shirt and instructed to wear it for a full day. To prevent outside odors from confounding the results, participants were not allowed to use deodorants or perfumes, ensuring that each shirt would carry only their own scent.

Experimental Approach

After the 24-hour wearing period, the T-shirts were collected and processed in the laboratory. Each shirt was cut in half, and the pieces were sealed in separate bags. The scent analyst, Joy, received the labeled samples without any information about the participants. She was asked to smell each half-shirt and decide whether it belonged to someone with Parkinson's or not. This process was double-blind; neither Joy nor the researchers knew the correct answers until the test was completed.

Key Steps:

Volunteers wore new T-shirts for 24 hours
No scented products were used
Shirts were cut and bagged for masking identity
Joy judged each sample based purely on smell

Findings and Evaluation of Correctness

When the researchers reviewed the outcomes, they found that Joy had accurately identified all six individuals with Parkinson's by scent alone. She was also able to match both halves of each T-shirt without error. The only exception was one member of the control group, who was wrongly marked as having the disease, resulting in a single false positive among twelve trials.

Group Correctly Identified Incorrectly Identified Parkinson's (6) 6 0 Control (6) 5 1

Joy achieved an overall accuracy rate of over 90%. Despite the small sample size, the results suggested that her sense of smell could distinguish a scent linked with Parkinson’s, although further investigation was needed due to the single misidentification and limited number of participants.

Investigating What Causes the Distinctive Parkinson’s Scent

Sebum as the Key Factor

Researchers initially assumed the source of the Parkinson's odor would be sweat, especially from the armpit region. However, observations during scent testing indicated the smell was more pronounced around the neckline and upper back. This pointed to sebum, an oily substance produced by sebaceous glands that protects and moisturizes skin, as a more likely origin of the odor.

A brief comparison:

Potential Source Observed Scent Location Research Focus Sweat Armpits Less likely Sebum Neckline, upper back areas More likely (indicated)

This finding led researchers to explore whether changes in sebum composition in Parkinson's patients might be responsible for the different scent.

Obstacles in Advancing the Sebum Study

Efforts to launch a detailed examination of sebum anomalies in people with Parkinson's disease encountered significant barriers. Securing funding proved challenging, largely due to skepticism from the broader scientific community. Many saw the project as too speculative, especially since it was based on the observations of one individual with an unusual sense of smell, and her single testing session did result in one incorrect identification.

Because of these challenges, the planned follow-up study into the role of sebum was put on hold. Progress depended heavily on the availability of financial support and overcoming doubts within scientific circles.

Reactions Within the Research Field

Doubts and Financial Hurdles

Many researchers viewed the idea of detecting Parkinson's disease through scent with skepticism. The claim that a person could consistently identify the condition by smell alone was seen as highly unconventional, particularly since this ability had only been demonstrated in a single, unreplicated experiment. This skepticism led to difficulties in securing grants or sponsorship for further work.

Funding agencies and institutions were reluctant to back a project grounded on one individual's unusual sensory acuity. Questions about scientific rigor and concerns about the potential for error discouraged financial investment. Even though the experiment yielded impressive results, the presence of a false positive and the perceived unorthodox nature of the research led to its dismissal by most funding bodies.

Challenge Impact Unconventional premise Reduced credibility Single-person study Concerns about reproducibility False positive result Decreased confidence in reliability Funding refusals Halted follow-up investigations

Obstacles to Continuing Studies

Progress stalled because of more than just funding problems. The broader scientific community was hesitant to take the findings seriously, citing the small sample size and questions about whether the results could be repeated on a larger scale.

Without broad support, the team could not expand their research to confirm the initial findings or explore the underlying chemical processes. The reluctance to revisit the project meant that important questions about what exactly was being detected—or whether this detection could be standardized—remained unanswered.

The study's limited scope prevented validation.
Institutional reluctance halted further experiments.
Unresolved questions about the biological mechanisms involved.

In summary: The research team faced serious obstacles due to doubt about the findings and restricted funding, which prevented more extensive investigation and kept questions about the phenomenon unresolved.

Continuation of the Research

After the initial experiment where Joy was able to identify people with Parkinson's using only her sense of smell, the research team sought to understand what exactly was causing this distinct odor. Although their first assumption was that sweat might be the source, observations during the study revealed that the scent seemed most noticeable near the neckline and upper back of the clothing, not the armpits. This led the scientists to consider that sebum, an oily substance produced by sebaceous glands, could be responsible.

The research plan shifted:

Focus: Analysis of sebum from Parkinson's patients and control participants.
Objective: Identify chemical anomalies in the sebum samples that could explain the difference in smell.
Method: Collect sebum from specific skin areas for laboratory analysis.

Obtaining funding for this line of research proved to be a significant obstacle. Despite strong interest from those involved, the broader scientific community remained skeptical. Concerns included the experiment’s dependence on one individual’s sense of smell and the limited sample size. As a result, further investigation was halted and the project was put on hold.

Factor Status Initial experiment Completed Source of odor Examined Sweat as cause Disregarded Sebum as focus Proposed Funding for follow-up Unavailable Research status Paused

The team recognized the need to determine the underlying compounds responsible for the odor, but progress was restricted by practical constraints, notably financial support and scientific skepticism. The investigation would have remained dormant if not for an unexpected event months later.

Final Thoughts

The experiment organized with Joy involved 12 participants, evenly split between those with Parkinson's and those without. Each person wore a plain white t-shirt for 24 hours, avoiding any scented products. The shirts were then processed in a controlled lab environment and provided to Joy for testing.

Joy's task was to identify, by smell alone, which shirts had been worn by people with Parkinson's. Remarkably, she correctly identified all six individuals with the disease and paired each shirt half accurately. One control subject was mistakenly classified as having Parkinson's, resulting in a single false positive among 12 trials.

Outcome Number of Cases Correct Identified 6 False Positive 1 Total Tests 12

While the study had a small sample size, the accuracy shown raised important questions. Researchers shifted focus from sweat to sebum, as Joy noted the scent was more prominent around the neckline and upper back. This led to a deeper investigation into whether anomalies in sebum among those with Parkinson’s could explain Joy’s observations.

Further research was limited by funding challenges and skepticism from the scientific community. Despite these obstacles, the findings prompted ongoing interest and highlighted the need for rigorous examination of unconventional observations.

Woman Who Can Smell Parkinson's Disease: The Extraordinary Scientific Discovery