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Why Medical Advice Seems to Change So Frequently
- wyager 10y agoI have no serious issue with fad-diet pundits and talk show hosts giving bad advice based on extremely weak science. My issue is when the government does this, and sets regulations, dietary guidelines, and school lunch rosters based on bunk. Changing the diets of millions of children at once should require airplane-construction levels of confidence, at the very least. Instead the FDA and FNS are running off low-confidence garbage and acting as if they have an authoritative standing, playing with potentially trillions of dollars of future utility differences spread across tens of millions of schoolchildren.
- noonespecial 10y agoWhat makes it worse is that they spend precious credibility on this nonsense so when something that should be as simple and important as "Polio will $%*& up your whole family, you should get this vaccine" comes along, they've got so little left that otherwise rational people doubt them and are suckered by quacks.
- paulddraper 10y ago> Changing the diets of millions of children at once should require airplane-construction levels of confidence The safe default for airplane construction is not to build it (or not fly it). There is no "safe default" for a diet...it's not like you can stop eating. So they'll serve their best guess of a good school lunch.
- gozur88 10y agoWe have thousands of years of experience in feeding children. Changing a dietary recommendation should require iron-clad evidence.
- JoeAltmaier 10y agoFor most of history, children have been fed badly. Its a hyperbolic exaggeration of the first order to claim millennia of experience.
- opportune 10y agoI feed my children only sunshine and they usually stop complaining after 2-4 weeks.
- paulddraper 10y ago> Changing a dietary recommendation What if the original dietary recommendation lacked iron-clad evidence?
- zaphar 10y agoThen goal one is to get some iron-clad evidence so your next recommendation doesn't make it worse. Just because a mistake was made the first time isn't an excuse to make the same mistake a second time.
- paulddraper 10y agoOnce you have iron-clad evidence of a diet better than all other diets, you've reached the end. Congratulations.
- gozur88 10y agoYou don't need to be better than all other diets. You just need to be better than the previous recommendation.
- zaphar 10y agoThis is a red herring argument. You don't need iron-clad evidence of a diet better than all diets. You only need iron-clad evidence for smaller specific recommendations. This doesn't have to be an all or nothing diet. In fact with nutrition it probably can't which means advice should be both well-researched and more nuanced than it currently is. Neither of which changes the point that making recommendation with little to no quality research is more likely to make it worse than make it better and you'd be better off just staying where you are until you understand the problem better.
- wyager 10y agoA better (i.e. less risky) approach is to have smaller administrative units (like states) deciding what to feed kids (assuming we can't find some way to not have the government, with its inherent ulterior pork-barrel motives, feeding children). Even if the odds of any given administrative unit making a bad choice are the same, we're at least very unlikely to malnourish every child in every administrative region.
- nradov 10y agoJust to play devil's advocate here, if the old dietary guidelines were bunk and the new replacement guidelines are also bunk then are we any worse off?
- Gustomaximus 10y agoQuite possibly. There will be levels of mis-advice. You may be moving from limited damage fallacy to a seriously damaging one.
- wyager 10y agoNot necessarily, but the point is that the government shouldn't be giving this advice in the first place. We'd be better off if we recognized that there is no objective answer. That will encourage us to follow actually good risk-mitigation strategies like per-state food programs.
- andreareina 10y agoThey're dispensing medical advice[1], so I do have serious issues with fad-diet pundits and talk show hosts giving advice based on weak science. [1] It's medical advice, quack miranda warning[2] be damned [2] http://scienceblogs.com/whitecoatunderground/2008/01/14/quack-miranda-warning/ http://scienceblogs.com/whitecoatunderground/2008/01/14/quac...
- nacc 10y agoFor many assertions, my quick filter is: what the _direct_ experimental design would look like to draw such conclusions? Is it possible that it is done somewhere? Biology is so complex and we know so little about it, so that the normal logic often fails on it: if A -> B, B -> C, you need to do experiments to show A -> C. Error accumulates, other unknowns come in. If you have to draw conclusion by logic in biology, look at the errorbars and sample size. Then stretch the errorbars by the square root of the sample size. Then stretch it again 3 times. If the conclusion still look obvious to you, proceed with caution.
- wfunction 10y agoI know zilch about biology or medicine but my impression is that in biology even A->B doesn't imply A->B half the time. Like you might do a large study and find that people get obese after consuming fat, only to later find that if you do the same with a different group of people, that doesn't happen. (Exaggerating with an example here, not actually claiming this particular example is true. Just trying to illustrate my impression of what a lot of things in the field are like.)
- noobermin 10y agothat's essentially what he said.
- kbutler 10y agoScience: Observe. Generate hypothesis. Design experiment(s) that would invalidate hypothesis. Test. Evaluate. Repeat as needed. Apply, and measure effectiveness. Continue to evaluate as new data is gained. Scientism: observe. Generate hypothesis. Apply. It's not just medicine, but basically anything that tries to assert credibility by being "science-based", rather than "proven".
- taneq 10y agoThings which assert credibility by claiming that they're "proven" are some of the worst. Sadly there's no real way to know the difference other than having a scientific background and examining the actual research.
- didibus 10y agoThe belief that proven exists is the bigger problem. Things are proven mathematically within a single model, nothing in reality is proven. There is only a scale from models that are more useful and likely to give us what we want, and models that are less likely. But, things can be disproved. So if we have a single case against a model, we know it does not hold 100%. The model is then insufficient. In that sense, we need to know: are the medicinal models presented to us known to not be the most useful and likely to help us? If they're not, then they're still valuable, and we should be happy that we're improving them at a high pace, giving us the impression previous models were wrong, yet models are not wrong, just less useful and likely to help us, but if it was still the best we had, your chances were still better following it.
- bjt2n3904 10y ago> Things are proven mathematically within a single model, nothing in reality is proven. Preach it didibus! So few people understand this!
- wott 10y ago"But it's been proved by research on neurosciences" claimed by psychologists/sociologists/economists is one of my favourites of the moment.
- rscho 10y agoIn view of other comments, it seems useful to point out that credible evidence is nonexistent in the medical field. I am an M.D. with 7y experience in the clinics, have done my share of research, and i can assure you that "scientific evidence" in medicine is a humongous s*load of tampered data written by people who have absolutely zero idea of what science is.
- WheelsAtLarge 10y agoI'm not an MD but after reading about how the USDA's pyramid of foods came to be. It shows how the power of politics and the power of money dictated grains as the base rather than vegetables. Or how eggs became enemy number one against cholesterol, not because of research but because someone thought that high cholesterol food equals high cholesterol in people. While it may seem to make sense that should not be the way to recommend food choices for millions. Where's the science? Yet it was sold as advice based on science. Anyhow I agree with you 100%.
- tiglionabbit 10y agoAnd the assumption that cholesterol even causes heart disease.
- wfunction 10y agoI'm afraid I see literally no way to evaluate this sort of comment based on its merits. Given you're anonymous here, any chance you could link to well-known/credible professionals who agree with you?
- WheelsAtLarge 10y agoI know you're not asking me but here are 2 that back my claims. http://www.healthy-eating-politics.com/usda-food-pyramid.html http://www.healthy-eating-politics.com/usda-food-pyramid.htm... http://well.blogs.nytimes.com/2014/11/14/ask-well-how-many-eggs-can-i-eat/ http://well.blogs.nytimes.com/2014/11/14/ask-well-how-many-e...
- droopyEyelids 10y ago
- empath75 10y agoPart of the problem is that properly designed medical experiments on humans are an ethical minefield so there are compromises all over the place.
- jamez1 10y agoIt's a failing of the industry to treat nutrition as cause and effect when the body is clearly a complex system. Then again, it's hard to pick a complex system that we do model properly.. the economy, the climate, the body, etc..
- chipperyman573 10y agoIf humans were removed from the equation, we could accurately model the economy and climate (to a reasonable degree). Human randomness adds too much entropy to the system to accurately model it.
- zaphar 10y agoThat is a claim I'm not sure I believe. Why do you think removing Humans would reduce the complexity sufficiently to model the weather which any usable accuracy?
- ncallaway 10y agoThe climate is perfectly chaotic without human involvement. Much the same way that the three body problem is chaotic whether there are people involved or not.
- jamez1 10y agoPerhaps I need to clarify, these systems are chaotic hence the difficulty in modelling them, I didn't mean to imply anything political. https://en.wikipedia.org/wiki/Complex_system https://en.wikipedia.org/wiki/Complex_system
- jodrellblank 10y agoIdlewords always a good read, the history of Scurvy and Vitamin C has some great content relating to science and diet, how difficult it is to get conclusive evidence, and how easy it is to jump to the wrong conclusions over and over: http://idlewords.com/2010/03/scott_and_scurvy.htm http://idlewords.com/2010/03/scott_and_scurvy.htm including quotes / sections: - It has been known since antiquity that fresh foods in general, and lemons and oranges in particular, will cure scurvy. Starting with Vasco de Gama’s crew in 1497, sailors have repeatedly discovered the curative power of citrus fruits, and the cure has just as frequently been forgotten or ignored by subsequent explorers. - 1747, James Lind proved in one of the first controlled medical experiments that citrus fruits were an effective cure for the disease. [..] the experiment involved two sailors eating oranges for six days. Lind went on to propound a completely ineffective method of preserving lemon juice (by boiling it down), which he never thought to test. - Knowing that citrus fruits deferred scurvy, but not knowing why, assuming it was to do with acidity, and switching to a cheaper British source of 'limes' instead of a foreign source of 'limes' - and accidentally switching from effective fruit to ineffective fruit, without noticing. - Knowing that citrus fruits avoided scurvy, but not knowing that copper breaks down Vitamin C, and keeping the juice in copper containers on ship. - the time Pasteurized milk was found to be better for preventing bacterial infection in infants, so rich parents switched to it. And the heating denatured Vitamin C so their children developed scurvy. Poor children, being breast fed, didn't get scurvy, only richer children. - The sickness could be fitted to so many theories of disease—imbalance in vital humors, bad air, acidification of the blood, bacterial infection—that despite the existence of an unambigous cure, there was always a raft of alternative, ineffective treatments. At no point did physicians express doubt about their theories, however ineffective. - Finally, that one of the simplest of diseases managed to utterly confound us for so long, at the cost of millions of lives, even after we had stumbled across an unequivocal cure. It makes you wonder how many incurable ailments of the modern world—depression, autism, hypertension, obesity—will turn out to have equally simple solutions, once we are able to see them in the correct light. What will we be slapping our foreheads about sixty years from now, wondering how we missed something so obvious? And plenty of other things they thought about ptomaines, contaminated tinned food, stuffy air, lack of light, poisons to avoid, and all without good experiments and with plenty of grabbing a ray of hope and committing everything based on it.
- mrfusion 10y agoI'm still confused about saturated fats. Can I eat butter with abandon or not?
- knodi123 10y ago"Moderation in all things". - Roman playwright Terence, circa ~200 B.C. Still good wisdom, twenty two hundred years later.
- nol13 10y agoabsolutely, as long as you still get enough protein, vitamins, and fiber and remain within your target calorie intake. (hard to do that if you're eating 1,500 calories of butter though of course) not a nutritionist but i did stay at holiday in express last night.
- e2e8 10y agoHere is a post about fats from the same author: http://theincidentaleconomist.com/wordpress/a-study-on-fats-that-doesnt-fit-the-story-line/ http://theincidentaleconomist.com/wordpress/a-study-on-fats-... Conclusion: "Should we be eating more polyunsaturated fats? Should we be avoiding saturated fats? The honest answer is: I don’t know. Given my review of the evidence, I stand by my previous recommendations [1], which essentially focus more on foods and less on nutrients. I think the state of nutrition research in general is shockingly flawed." [1] http://www.nytimes.com/2015/04/21/upshot/simple-rules-for-healthy-eating.html http://www.nytimes.com/2015/04/21/upshot/simple-rules-for-he...
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- jklp 10y agoIf you haven't already subscribed the author (Dr Aaron Carroll) runs his own YouTube channel - Healthcare Triage (https://www.youtube.com/user/thehealthcaretriage https://www.youtube.com/user/thehealthcaretriage) Highly recommended if you're interested in the space
- mk827 10y agoI grew up in India surrounded by a whole bunch of general health and nutrition advice which seems to be an aggregation of centuries of culture specifically suited to my culture, location and genetic makeup. There's no evidence for any of it, but it is what seems to have been learnt over the years. I have somehow always trusted it more than these ever changing fads that the newspapers were too eager to push at me. I know though that by the scientific yard stick these traditions don't stand up to scrutiny but I studied enough science to understand that these general advisory guidelines were as likely to be hocus pocus as my grandmother's so called wisdom. Mind you this is not about western medicine, just about food and lifestyle recommendations. #justsaying.
- AstralStorm 10y agoIt's applying leeches still recommended for most health conditions there? What makes you trust one ancient knowledge over other ancient knowledge?
- umberway 10y agoI would agree that the medical field is plagued with empiricism which consists of asking a naive question (rather than working from a deeper theory) and then doing a study to 'measure' the thing in question. Third parties then note the correlation and issue 'advice' in the form of suggestive reporting. I would guess this puts the public off science altogether! Perhaps the best way to look after the body will turn out to be as Aubrey de Grey suggests: regular servicing to repair accumulated damage. But we aren't there yet. Plus we urgently need new antibiotics.
- Fomite 10y agoThe medical field is very much based off one-off effect estimates, but there's starting to be some pushback on this. I've seen it mentioned several times that there's value to be had in theory from relatively prominent people in epidemiology.
- umberway 10y agohttp://www.goodreads.com/quotes/6894316-never-trust-an-experimental-result-until-it-has-been-confirmed http://www.goodreads.com/quotes/6894316-never-trust-an-exper...
- onion2k 10y agoThe news only reports change. If the advice isn't changing then it won't be in the news. That makes it feel like everything is changing because we conviently ignore all the advice that hasn't changed. If you look at medical advice as a whole it hardly changes at all, so most of it never gets in the news. Also, most people follow news organisations that are fastest instead of following the organisations that are slower but rigourous. It doesn't matter if the advice is wrong; it still gets more eyeballs.
- general_ai 10y agoGreat entertainment for anyone with basic knowledge of statistics: read medical papers. Lots of laughs to be had. Most experiments are bogus. Most conclusions are drawn with little in the way of supporting evidence, often without controlling for obvious confounding factors. Correlation is implied to mean causation. Extrapolations abound, both for concentrations (i.e. if I give this mouse a megadose of X it'll die, hence X is harmful) and between species (mice grow tumors if I give them a ton of X, so humans will too if they consume a tiny fraction of the amount per unit of body weight). Most of it is basically bro science, except expressed in much longer words.
- timcederman 10y agoActually sourcing the data via PubMed has been eye opening for me, and I saw all those things. I am amazed by the number of news articles that cite conclusions as factual for humans, but on reading the source, they have only been shown in mice studies.
- general_ai 10y agoAnd quite often they're obviously bogus even in mice, especially if the author seems to have a political axe to grind (e.g. anti-GMO, anti-sweetener, anti-herbicide, etc).
- amelius 10y agoIt would be nice to see a meta-study on this.
- general_ai 10y agoI agree. But peeing in other people's cereal is a perilous endeavor.
- DanBC 10y agoCochrane reviews frequntly say "the available evidence is poor, more research is needed", and "we found X relavent papers, but had to exclude Y which were low quality."
- Angostura 10y agoSo, Doctor - you're telling me that vaccines could well cause autism? If you're not saying that, why not? Given that "credible evidence is nonexistent in the medical field."
- rscho 10y agoSo, anonymous sarcastic individual - As I am sure you are aware, this specific controversy began with a big fraudulent study. You still see controversial data pop up now and then, but the topic is so much a political and public health matter, that you would be very naive to take anything anyone has to say about the medical evidence for granted. What I can say is that, knowing nothing better, I rely on the very likely abysmal quality of medical evidence on the subject to say that vaccines do not cause autism. You can quote that as my official opinion.
- dang 10y agoThis crosses the line into incivility, which is the last thing we want on HN, especially when talking with domain experts whom we're lucky to have in this community. Please conduct yourself better than this in the future. We detached this subthread from https://news.ycombinator.com/item?id=13423680 https://news.ycombinator.com/item?id=13423680 and marked it off-topic.
- Angostura 10y agoI'm sorry, but when an individual descends into hyperbole by dismissing an entire branch of research endeavour with 'credible evidence is nonexistent in the medical field' - it is worth attempting to find out whether they actually believe that there are simply no good studies ever carried out. The 'So Doctor' was unfortunate - I was framing a response from a fictious patent walking into his/her surgery, but the wording doesn't work and I can see how it appears aggressive. Nonetheless, yes when there are organisations such as https://www.nice.org.uk https://www.nice.org.uk and http://www.cochrane.org http://www.cochrane.org trying their hardest to pull together the best evidence out there, this broad dismissal is irritating.
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