7 ms·
CD is definitively associated with the occidental modern way of life 3. If the cold chain hypothesis is valid, the emergence of CD must be parallel to the devel
by DoreenMichele 5y ago
CD is definitively associated with the occidental modern way of life 3. If the cold chain hypothesis is valid, the emergence of CD must be parallel to the development of industrial and domestic refrigeration. Figure 1A compares the annual incidence of the disease and the household equipment rate in several countries. There is a temporal correlation between these variables. It should be noted, however, that in a given country the disease begins to be detectable not at the time when refrigerators begin to be sold, but only when about 50% of households are equipped. This observation is counter-intuitive.
It's an interesting hypothesis and I like the thinking. We need more of this kind of investigation.
The problem I see is that refrigeration should reduce the incidence of food poisoning and malnutrition generally and generally improve survivability of vulnerable populations. So one possibility is that people who used to die mysteriously in early childhood are now living long enough to be diagnosed with various ailments.
In other words, maybe modern life does cause Crohn's or maybe it just lets such people survive and get diagnosed and learn to live with their condition.
- sporedro 5y agoThis reminds me of what I read about Nicotine and how it was thought to prevent Alzheimer's, but I believe it was just the fact those smoking tobacco had a lower chance to live to the age to be diagnosed or develop it.
- ralusek 5y agoMotorcycles prevent old age.
- smokeyfish 5y agoOld age prevents older age.
- ralusek 5y agoBirth is the leading cause of death.
- bigodbiel 5y agoI think you are confusing with Parkinsons, and there is a co-relation with dopamine receptors, and it's proven. Also, this being a Crohn's post, smoking also has benefits in curtailing Inflammatory Bowel Disease, but not Crohn's edit: more specifically smoking decreases the incidence of ulceraive colitis (an IBS)
- FearlessNebula 5y agoUC is not an IBS (irritable bowel syndrome), it is an IBD (inflammatory bowel disease) of which I believe crohns is as well.
- DoreenMichele 5y agoMany years ago on a discussion list for a really deadly condition, someone talked about a child in the family dying really young and no one knew why and everyone was so heartbroken and felt so guilty. And I guess later someone else was diagnosed with this very deadly condition and eventually someone suggested to the mother of the child "Maybe the child also had this deadly genetic disorder and they were just not diagnosed. Maybe you didn't do anything wrong." And the mother was finally able to make her peace with the mysterious death of this child, who had been maybe five years old. I think the person who told the story was a lot older than me. Children dying young tends to be a thing in less developed countries and people don't necessarily know why.
- 8ytecoder 5y agoMy family tree from a mere two generations ago is filled with kids who died under the age of 5 - some are mundane but most are undiagnosed. They just know the symptoms that were fatal not the cause. 1960s and earlier. That’s not at all that long ago.
- deleted 5y ago[deleted]
- heresie-dabord 5y agoSurvivorship bias https://en.wikipedia.org/wiki/Survivorship_bias https://en.wikipedia.org/wiki/Survivorship_bias
- epgui 5y agoFun fact: strangely enough, there are two conditions for which smoking is known to be a protective factor. Parkinson's disease, and Ulcerative Colitis (UC). Interestingly, though Crohn's Disease (CD) and UC are strikingly similar forms of IBD, nicotine has the opposite effect on both. Nicotine will increase inflammation in CD and reduce it in UC, through the a7 receptor and up/down-regulation of Treg cells: https://www.jimmunol.org/content/187/5/2677 https://www.jimmunol.org/content/187/5/2677
- jsmith99 5y agoFor colitis, it doesn't seem to simply be the nicotine as studies using nicotine patches saw little or no effect. This suggests the smoke itself may have some effect. There is a summary at https://www.crohnsandcolitis.org.uk/about-crohns-and-colitis/publications/smoking-and-ibd https://www.crohnsandcolitis.org.uk/about-crohns-and-colitis....
- colechristensen 5y agoSmoking also makes you less likely to contract covid but more likely to have serious outcomes from it if you do. Something about the immune reaction to the smoke being beneficial to avoid infection and the long term lung damage making it worse when infected.
- edmundsauto 5y agoIs that true when adjusted for close human connection? My understanding of smoker culture is they are less likely to be in close quarters with other people, unless those others are also smoking. And then they tend to be outside.
- Retric 5y agoMy suspicion is it’s a byproduct of coating the lungs with tar. You sacrifice lung function for a slightly more robust physical barrier. The obvious test for immune system response would be if chewing tobacco users would see similar resistance to infection. Hopefully this will eventually clear things up: https://clinicaltrials.gov/ct2/show/NCT04896918 https://clinicaltrials.gov/ct2/show/NCT04896918
- robbiep 5y agoI haven’t seen nicotine as being protective for alzheimers, but it is protective for Parkinson’s and Ulcerative colitis. In fact during medical school I saw a young patient who was trying to get healthy to help deal with her autoimmune issues, and had stopped smoking, inadvertently likely triggering a massive flare of UC
- racecar789 5y agoI can personally attest this is true. Nicotine does help with ulcerative colitis. I buy Swedish snus which is far less toxic that American tobacco.
- colordrops 5y agoWhy not just vape?
- deleted 5y ago[deleted]
- racecar789 5y agoVaping is certainly an option.
- blamestross 5y agoThat's relatively easy to correct for. This is an animal study, which doesn't have that bias: https://www.sciencedaily.com/releases/2016/09/160920160635.htm https://www.sciencedaily.com/releases/2016/09/160920160635.h... Basically, this is why I vape. Early onset dementia represents much higher existential risk than vaping does.
- zuj 5y agoI am going to add this to my list of examples for survivorship bias. https://en.wikipedia.org/wiki/Survivorship_bias https://en.wikipedia.org/wiki/Survivorship_bias
- roody15 5y agoI wonder too if it has to do with the eating. People who eat less and intermittently fast have lower rates of Alzheimer’s. The thought is when you fast your body recycles excess proteins that build up on your brain, reducing brain plaque buildup over time. Nicotine is a known appetite suppressant.
- Flankk 5y agoIt most often begins in young adults and lasts a lifetime. Second sentence in the paper.
- epgui 5y agoBiochemist: agreed, "we now live long enough to suffer from it" works well to explain the rising prevalence of cancer, but not that of auto-immune diseases. For auto-immune diseases, the consensus (if we can call it that) mostly revolves around the hygiene hypothesis. Refrigeration is one aspect of this, but other things that fall in this category are the use of soap, rising cleanliness standards, disinfectants, aseptic methods, positive pressure toilets and good sewage systems, vaccines, antibiotics, not breastfeeding as much (not directly a hygiene issue, but breastfeeding transfers passive immunity to a child with a developing immune system, which has an effect not unlike being exposed to a different spectrum of microbes), caesarian births, always eating very fresh meats and vegetables, etc. There is a grain of truth to "what doesn't kill you makes you stronger" (but don't take that idea too far, and please do wash your hands and do get vaccinated, for god's sake), and the essence of the hygiene hypothesis, in comp sci / ML terms, is that it's a training set problem. Edit: it's unclear to me why people are downvoting this. This is my area of expertise, so I'd be curious to know what people find objectionable in this comment.
- tehjoker 5y agoIf it's a training set problem, wouldn't it be possible to give a "vaccine" consisting of a reasonable mix of antigens from time to time? Has this been tried?
- djd20 5y agoThat's how many vaccines work... dead versions of pathogens.
- epgui 5y agoIt's not completely inconceivable that we will one day have therapeutic approaches in that line of reasoning, but it's also not quite that simple. There is a critical period during infancy and early childhood when the immune system goes through a number of critical maturation processes. Afaik, once that's done there's no going back to a perfectly fresh slate. After puberty, for example, your thymus (an important site for T cell maturation) begins shrinking and eventually all that remains of the organ is basically non-functional traces of scar tissue. That is not to say that T cell maturation doesn't occur afterwards, but it is a particularly striking example of the irreversible age-related change we can be talking about. Another less-obvious example is that children born by cesarian have a different skin and gut flora through the rest of their lives than children who are born through the vaginal canal: the initial colonization of the skin with a different set of bacteria has some degree of permanence, though it is also somewhat plastic. Yet another example, children who are breastfed tend to have fewer food allergies or auto-immune diseases (atopy, generally) than children who are fed formula. Early conferral of passive immunity through maternal antibodies secreted in breast milk selects for different populations of gut microbes, and again there is some degree of permanence to this. In both cases, the differences are measurable throughout adulthood!
- VWWHFSfQ 5y agoIt reminds me of how poverty and gun violence dramatically reduced after Roe v. Wade because organizations like Planned Parenthood started installing themselves in minority communities and advocating heavily for abortions.
- yeetman21 5y agominority communities or poorer communities? also any link to a study, seems very interesting
- kortilla 5y agoCorrelation != causation. You should be extra skeptical when there are convenient political points to be gained when implying such causations. Also, freakonomics is just entertainment, not science. Poverty and gun violence also reduced after they took lead out of gas. https://www.motherjones.com/environment/2016/02/lead-exposure-gasoline-crime-increase-children-health/ https://www.motherjones.com/environment/2016/02/lead-exposur...
- VWWHFSfQ 5y agoFrom your article: > When Rudy Giuliani ran for mayor of New York City in 1993, he campaigned on a platform of bringing down crime and making the city safe again. > Since 1960, rape rates had nearly quadrupled, murder had quintupled, and robbery had grown fourteenfold. > Giuliani won the election, and he made good on his crime-fighting promises [...] > The results were dramatic. In 1996, the New York Times reported that crime had plunged for the third straight year, the sharpest drop since the end of Prohibition. Since 1993, rape rates had dropped 17 percent, assault 27 percent, robbery 42 percent, and murder an astonishing 49 percent. I'm not sure what point you were trying to make, but nobody disputes that Giuliani's policies on crime were extremely effective. Maybe they had some undesirable side-effects for the minority communities that were most affected by the policies. That should definitely be addressed. But those communities became safer and more affluent in the meantime.
- jtbayly 5y ago
- Vetch 5y ago> refrigeration should reduce the incidence of food poisoning According to the paper, the implicated Yersinia are able to survive the cold at refrigeration temperatures and in vacuum packaging. Due to longer storage times and reduced competition, the bacteria are able to proliferate. In the genetically susceptible, they trigger an "exacerbated inflammatory response". Interesting, the paper also posits mutations in descendants of those who survived the genetically close black plague causing bacteria might cause them to be susceptible.
- xyzzy21 5y agoAlso the evolutionary "eye of the needle" of the Black Death could give rise to the mutations in European alleles making them sensitive.