This reminds me of when I was in the Navy -- at one point I had lived with hundreds of other guys in a ship's berthing and at another duty station I mentioned to a coworker that I could determine someone's race from their sweat. Of course, they called bullshit on that statement (as I'd imagine most on here would) and we tested it out with 4 guys (1 black[1], 2 white[2], 1 hispanic[3]) who sweated into the same size shirts, and I was able to identify them with 100% accuracy. Another time, I walked into a cubicle, wrinkled my nose, and said "Man! It smells like an old deck of cards in here!". One of the guys standing next to me then pulled out a rather well-played-through deck of cards out of his pocket.<p>One of the reasons people give for the difference in smell are the difference in foods that different cultures eat. I definitely know this is not the case, as everyone on that ship was eating the exact same food, and their smells were extremely distinct.<p>I understand that lack of science applied to my specific anecdotes, but I think there's something to be said for having a keen sense of smell, since people are already geared towards smelling other people's sweat to determine immunocompatibility[4].<p>[1] A black person's sweat is the one I can identify with absolute certainty, as it's completely unmistakable for anything else<p>[2] A white person's sweat smells like a distinct type of onion to me<p>[3] I couldn't really identify his race if it were just this shirt, but had that one by process of elimination.<p>[4] <a href="https://en.wikipedia.org/wiki/Major_histocompatibility_complex_and_sexual_selection#MHC-mediated_mate_choice:_case_studies" rel="nofollow">https://en.wikipedia.org/wiki/Major_histocompatibility_compl...</a>
The thing that most surprised me were the odds that a person in the control group (no parkinson's), actually did have parkinson's (diagnosed early according to the woman) and was diagnosed later to indeed have parkinson's.<p>After all, the prevalence is 0.3% in the general population. The odds at least one of the six in the control group had parkinson's is around 2% (even less considering it's already a filtered audience in a way). Not impossible but very unlikely, which incidentally makes her insistence of that single particular person to have PD all the more interesting.<p>There's definitely something there, looking forward to more testing.
<i>"Her accuracy was 11 out of 12. We were quite impressed."<p>Dr Kunath adds: "She got the six Parkinson's but then she was adamant one of the 'control' subjects had Parkinson's.<p>"But he was in our control group so he didn't have Parkinson's.<p>"According to him and according to us as well he didn't have Parkinson's.<p>"But eight months later he informed me that he had been diagnosed with Parkinson's.<p>"So Joy wasn't correct for 11 out of 12, she was actually 12 out of 12 correct at that time.<p>"That really impressed us and we had to dig further into this phenomenon."</i><p>Reminds me of the story I heard about a doctor who was diagnosing an STD a lot earlier than average. They put two other doctors in the room with him to try to spot what he was seeing and identified the eye flutter as a new symptom, I think for syphilis.
Reminds me of this anecdote from Fishing with John:<p>"I heard a story about this woman that was swimming in the ocean, and dolphins started swimming with her, and the dolphins kept poking her in the chest above her breast. She got scared and they took her out of the water, and she had a big bruise right on the top of her breast. They took her to the doctor to examine her, and they did a mammogram, and found that she had cancer right in that spot."<p>– Jim Jarmusch, 'Fishing with John'<p><a href="https://youtu.be/uVa8rj1mm7A?t=912" rel="nofollow">https://youtu.be/uVa8rj1mm7A?t=912</a>
There are a couple people picking on this research in the thread. This is a preliminary study, just a "bullshit test" to see if this woman is crazy or if she's not. It's obvious that she's not crazy, because all she's doing is sniffing t-shirts and she doesn't know who they belong to. The sample size is large enough, we have a p-value of no more than p=0.0012, and that's under the cynical assumption that she somehow knew that exactly seven of the twelve samples would have Parkinson's... something that the scientists didn't know.<p>So we know that <i>something</i> is going on here. The next steps are to control potential confounding variables and to determine the sensitivity and specificity of the test, if it's shown that she's not actually detecting some confounding variable. This is where you go double-blind, you use larger sample sizes, et cetera, now that you have money. You have money because the preliminary research was promising.<p>And we're not just getting a good test out of this. If there's an actual chemical that she's smelling, then there's some chemical process that's going on in people with Parkinson's which isn't happening in people without Parkinson's (or vice versa). Tracing these chemical pathways could give us clues to the etiology of the disease, which would be a REALLY BIG DEAL. Or maybe it's just a rabbit hole.
I know the odor she is talking about. My husband was diagnosed in January. His previous truck and his current vehicle have developed a very distinct odor. I used to say old musty Portuguese man but I realize it is the smell she is talking about. My husband has only used deodorant for 27+ years. This came about because anti-perspirant made his entire armpit swell with bright red welts. He also does not sweat much. It is a very sad disease, but will continue to search for ways to make it easier.
Interesting given the recent link between Parkinsons/Alzheimers and fungal infections: <a href="https://news.ycombinator.com/item?id=10401344" rel="nofollow">https://news.ycombinator.com/item?id=10401344</a>
Some more truly fascinating Parkinson's news this week about nilotinib, apparently seeming to cure Parkinson in small trials... <a href="http://www.independent.co.uk/life-style/health-and-families/health-news/parkinsons-patients-given-new-lease-of-life-after-receiving-cancer-drug-in-trial-a6699031.html" rel="nofollow">http://www.independent.co.uk/life-style/health-and-families/...</a>
Can anybody tell us what is the current state of the art in "electronic nose" sensors technology? Could they potentially be used to identify this smell?
My grandpa died of parkinson's, its a really slow and heartbreaking disorder. I think early diagnosis would be wonderful. It runs in the family, and his two older brothers and father had it, so he lived a very preventative lifestyle - especially with respect to daily exercise. I think it paid off, he lived to 85 while both his brothers died 20 years younger.
Galen relied on sense of smell for diagnosing illnesses. Aristotle wrote about it. Until the late 20th century doctors often used smell for diagnostics.
It would seem there are some major confounding factors here not detailed in the article.<p>1) The population doesn't reflect a realistic test--if the overall incidence is 0.3%, but the sample size had 50% (or more given her adamant hit), then we need to know whether she was expecting more.
2) More importantly, the incidence in men is 1.49x that of women [1], and age also plays a factor. So given that the sample is already skewed towards a higher incidence of positives, the gender differences might be factored into her senses--especially since it was her husband who was her training set. With n=12, it would be very easy for the probabilities/priors to be much different than truly random. (E.g., the learning function of her nose might be "men + people over 65" which happened to match up with the test and control group quite well.") Or it could tune into medication used to treat the disease.<p>Great if true, but I am skeptical.<p>[1] <a href="http://jnnp.bmj.com/content/75/4/637.full" rel="nofollow">http://jnnp.bmj.com/content/75/4/637.full</a>
The question they did not ask what makes the body smell. When we eat garlic we smell like garlic. So the smell must be related to how the food is digested. The researchers should look at the gut flora, in other words they should do a study similar to this <a href="https://news.ycombinator.com/item?id=10439129" rel="nofollow">https://news.ycombinator.com/item?id=10439129</a> All disease start in the gut.
Looking forward to hearing more--reminds me of work done to detect cancer by scent with help from dogs:<p><a href="https://en.wikipedia.org/wiki/Canine_cancer_detection" rel="nofollow">https://en.wikipedia.org/wiki/Canine_cancer_detection</a>
This also reminds me of the breathe test being developed to check ammonia levels for certain kinds of patients:<p><a href="https://news.ycombinator.com/item?id=10402816" rel="nofollow">https://news.ycombinator.com/item?id=10402816</a>
I'm too lazy to do the math, but I'm just going to say a test like this needs more than a sample size of 12 to show significance for detecting something that happens 1 in 500. The woman also was predisposed to thinking that at least some of the 12 had Parkinson's and the sample selection ensured that at least half did have Parkinson's. An actual test would need to allow any possible sample including those that had zero Parkinson's patients.