Debunking medical myths
Does our hair and fingernails keep growing after we die? Do we only use 10% of our brains? Researchers from the Indiana University School of Medicine debunked a collection of medical myths that are familiar to all of us, even though there's no scientific evidence to support the claim. They published their results in the current issue of the scientific journal BMJ. From the paper:
Physicians understand that practicing good medicine requires the constant acquisition of new knowledge, though they often assume their existing medical beliefs do not need re-examination. These medical myths are a light hearted reminder that we can be wrong and need to question what other falsehoods we unwittingly propagate as we practice medicine. We generated a list of common medical or medicine related beliefs espoused by physicians and the general public, based on statements we had heard endorsed on multiple occasions and thought were true or might be true. We selected seven for critical review:Link
• People should drink at least eight glasses of water a day
• We use only 10% of our brains
• Hair and fingernails continue to grow after death
• Shaving hair causes it to grow back faster, darker, or coarser
• Reading in dim light ruins your eyesight
• Eating turkey makes people especially drowsy
• Mobile phones create considerable electromagnetic interference in hospitals.
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I love this kind of thing! Maybe I'm a dick, but I think people need to be reminded not to buy too heavily into their superstitions and/or popular wisdom. Plus, this is just fun science.
Yes, conventional wisdom basically means ignorant assumption that may be right but is probably wrong.
This is why I love the Quite Interesting game/panel show on British television. Besides showcasing four great comedians on most episodes, it's full of this kind of stuff. That's where I learned that nail/hair doesn't actually grow after death (they just seem to grow because the body loses moisture and shrinks) and loads of other stuff.
I think that the website is a little tongue-in-cheek. If you look at the home page there is an article about using chocolate truffles instead of orchidometers and responses to unicycling. All very funny though.
@#2 in regards to hair and nails growing after death , I agree, they don't. Their right in their explanation about fingernails receding and all of that. However, where I feel this came from is from the lack of earlier medical knowledge about death itself.
More than a few cases of people being buried alive led to the advent of the breathing tubes and bell pulls being added...to warn people that hey, I'm not dead. This is where I think it came from originally...where it would indeed look as though hair and fingernails grew while the person was 'dead'.
This article meets a ridiculously low standard for its debunking claims.
Shaving doesn't make hair darker or courser it just feels course and looks darker because it hasn't been exposed to the sun and isn't tapered. That's practically a confirmation not a debunking.
Cell phones only cause serious medical harm in 1% of cases and this is supposed to mean they're OK? The value of cell phones for doctors can be separated from the general prohibition. For non-doctors. So I'd call that confirmed not debunked.
And then there's that ridiculous sentence about to much water killing you. Do they think too little water doesn't kill more people than too much water?
This whole article is silly.
Stephen: to be fair, the article is saying that shaving will not make any permanent changes to how hair grows. The common wisdom is that the more you shave, the darker and coarser your hair will grow in the future. This is suggesting that while hair is darker and coarser as a direct result of shaving, that won't make it grow in differently a year later.
and I think you're reading too much into the article's mention of the danger of too much water. I don't think it was trying to claim that eight glasses of water a day is dangerously excessive, just that too much water is also a risk.
But I'd have to agree with you about cell phones in hospitals. Yikes! If I was told that there was a 1% of my phone causing a malfunction within 1 meter of a medical machine, I sure as hell am going to turn it off!
@#5, Stephen: You're over-reaching with the cellphones stats. Firstly, there is a world of difference between "serious medical harm" (your phrase) and "clinically important interference" (the phrase used in the report). Secondly, the same team at the Mayo clinic carried out a subsequent study in 2006, with cases of interference of any type adding up to a grand total of 0.
I am not surprised, despite all the science courses taken by pre-meds and medical students, very few of them really think like scientists (not that scientists do all the time, either). They memorize what they are taught and too few unlearn when they need too. I am very careful when selecting a physician to look for one with a publication record (I work near a research hospital and have that luxury). I find they are more willing to consider new evidence. It does not hurt that I am a biology PhD and I am more up to date on some of my conditions than they are. It sets up a different power dynamic, and not all of them are ready for that.
However legitimate this debunk is, Ive always asserted that the liquid consumption notion was absurd. Unless your in a very difficult environment or medically critical, its difficult to purposely ingest 2+ liters of liquid in one day.
Just last week I read a bunch of student essays about how cellphones kill people with pacemakers and destroy medical equipment and how that's why in Japan you're not allowed to use your cellphone on trains or in hospitals here.
When I handed them back, I explained why that was wrong (if it were true, JR would make you switch them off! --Hell, if it were true, they'd never be sold!) and suggested that JR and the hospitals just think it's annoying and so they made up a lie to justify it.
"You're killing the old people!!!"
I also pointed out that, as everyone knows, there are too many old people in Japan, so even if it were true, it might be a good idea to ignore the rule anyway.
No I didn't.
But it would have been funny if I had.
I can easily drink over 2 liters of liquid on a work day.
A glass of juice at breakfast.
A glass of water before I leave.
I drink about 1 to 1.5l of various drinks at work.
At least 3 glasses of milk/soy milk/juice/water/etc. at night.
I use both 8oz and 12oz glasses at home. That list is probably an overestimate but it still works out to about 3l (12 8oz glasses). I weigh about 135 lbs.
But I'd go crazy if it all had to be water (for one thing, I hate the plastic taste of bottled water), and I probably drink closer to 6 glasses if I'm not doing much.
I seem to recall (but alas don't have a cite) that the only (somewhat dubious) study to come out with the 10% figure was a qualitative claim that was misinterpreted as a quantitative claim. As the website notes, this misinterpretation stuck because it was highly profitable for mail-order, mind-improvement course salesmen to make it.
The original study was from the early days of high-def brain-scans and noted that whereas infant brain structure is pretty fluid (poke the tops of their heads and see!) by the time you're an adult you have, depending highly on how your brain is used and abused during its formative years, a pretty fixed structure. Structures that get used more get more blood supply and push out those that aren't. Several end-structures are more likely if you get dropped on your head when a baby or if mom drank heavily while pregnant. That sort of thing.
So then they did some kind of combinitorial analysis to enumerate the possible kinds of noticably different structures possible starting from an average baby brain: let's call that N. Then they did a small but widely scattered sample of adult brains (a few low-tech aboriginals, some fighter pilots and so on) and said that there only seemed to be about .1 N models out there.
So the claim that Homo Sapiens (the species) seem to be only using 10% of their (possible kinds of) brains was what got turned into the claim that individual Homo Saps were only using 10% of their (personal) brains.
Presumably the other .9 N brain setups would be useful for dealing with or would come about due to, situations that either haven't happened for a long time or have never happened: dealing with the Great Old Ones; DRM working; that sort of thing.
The water thing is a bit of a sticking point to me. Potable water for the masses is something of a new phenomenon, historically speaking. Beer and other beverages were preferrable because filtration was either non-existant or dreadful through much of human history. Now that you can get fresh water straight from the tap (or be a fool in the western world and pay more for a water than gasoline and get it in a bottle) I would think it would be preferrable to drink water.
Considering the health issues brought on by over consumption of sugars (high fructose corn syrup especially) present in many carbonated drinks I think sticking with water and juices as your main liquids is pretty solid.
Ugh, that was not an intentional pun.
Here is some medical research worth posting on the internet.
http://www.mercola.com/2003/jan/15/doctors_drugs.htm
This is not the only researcher that has come to this conclusion.
It always ruffles my feathers a little when I see an article that "debunks" the "myth" that we should drink 8 glasses of water a day.
I worry that a lot of people see this and miss out on an opportunity to improve their general well being, since many people - myself included are not always adequately hydrated. The Mayo Clinic recommends a male drink roughly 3 liters (13 cups, 102 ounces), and a female roughly 2.2 liters (9 cups, 75 ounces) of beverages a day.
The author's are correct that the recommendation to drink 8 glasses of water a day is false, it's actually a little more for a male. If we assume a glass is 12 ounces, 8 glasses doesn't meet the recommendation of the Mayo Clinic.
As noted a beverage doesn't necessarily mean water, although it's hard to think of some other liquid that would be equivalent to water from a health/calorie standpoint.
I'm going to go get a glass of cold water now...