Hair grows back thicker when you shave it! Reading in dim light turns you blind! Peeing on a jellyfish sting will soothe the pain! The way our bodies work is a bit of a mystery, and our desire to unlock its secrets has led to a vast amount of misinformation. Many of these false notions are more widely believed than the truth. We took our healthy scepticism and a bunch of research to find the truth behind some of the most common myths about our bodies and our health. Here’s what we learned.
Title image remixed from originals by Z-art (Shutterstock), Leremy (Shutterstock), and myVector (Shutterstock).
Myth 1: Body Hair Grows Back Thicker When You Shave It
You might remember that episode of Seinfeld where Jerry decides to shave his chest despite warnings that it will grow back twice as thick. Although the myth proves to be true on television, it’s very much false in the real world. If shaving caused hair to regrow much thicker, balding men would be shaving their heads for hair loss prevention. Children’s health researcher Rachel C. Vreeman and assistant professor of pediatrics Aaron E. Carrol put this myth to rest:
Strong scientific evidence disproves these claims. As early as 1928, a clinical trial showed that shaving had no effect on hair growth. More recent studies confirm that shaving does not affect the thickness or rate of hair regrowth. In addition, shaving removes the dead portion of hair, not the living section lying below the skin’s surface, so it is unlikely to affect the rate or type of growth. Shaved hair lacks the finer taper seen at the ends of unshaven hair, giving an impression of coarseness. Similarly, the new hair has not yet been lightened by the sun or other chemical exposures, resulting in an appearance that seems darker than existing hair.
Basically, shaved hair feels coarse and that leads you to believe it’s thicker. In reality you’re just fooling yourself and your hair remains the same.
Myth 2: Calorie Counting Is All That Matters For Weight Management
We might like to believe that calories-in-equals-calories-out is a sufficient weight loss theory, but that means we have to accept our bodies are pretty simple. While consuming fewer calories can certainly have an impact, not all foods have the same impact once we stuff them down our throats. If you want to think about it in a very simple way, consider the difference between a candy bar and a cucumber. They taste different, they consist of different nutritional elements, and are not the same thing. It doesn’t make sense that they’d be used by your body in the same way.
The problem with the idea of calories being the only necessary metric is that we think of a calorie as a physical thing. Calories are just a means of measuring heat, and they weren’t initially a term used in reference to food. A calorie, according to Wikipedia, “approximates the energy needed to increase the temperature of 1 gram of water by 1 degree Celsius.” Basically, calories are a measurement and not something your body uses for fuel. What your body does use is what it finds in the foods and liquids it digests. If you put crap in your body, you’re not going to be better off just because of a low-calorie rating.
The way your body processes sugar is an excellent example of how different foods yield different results. While the idea that health can come from eating a magic number of calories each day, the reality is that foods and your body are more complex. Pay attention to the composition of the foods you eat and you’ll wind up with much better results.
Myth 3: You Need Eight Hours Of Sleep Per Day
We’re told we need to sleep eight hours each night, and while that’s true for some it isn’t true for all. The Hindustan Times points to a European study that showed people who possessed a gene known as ABCC9 could sleep for significantly fewer hours than the average person. Finding the same gene in fruit flies, the scientists found that by manipulating it they could also manipulate the amount of time the fruit flies spent in a restful state. When we asked you how much sleep you require, the results varied quite a bit. For some, eight hours was necessary. For others, it was too much. Your experiences match this study.
Additionally, Wired Magazine profiled a chemical called Orexin A that is believed to work as a sleep replacement. It’s already present in humans in limited amounts, and when depleted causes us to feel tired. Since its discovery, Orexin A has been fashioned into a nasal spray (for testing purposes) to find out if it can be used as a treatment for narcolepsy. In a study at UCLA, a few scientists decided to make some tired monkeys snort the chemical:
The monkeys were deprived of sleep for 30 to 36 hours and then given either orexin A or a saline placebo before taking standard cognitive tests. The monkeys given orexin A in a nasal spray scored about the same as alert monkeys, while the saline-control group was severely impaired.
While information about Orexin A is still rather new, it points to the possibility that sleep may not be as relevant as we think it is. Either way, while eight hours of sleep isn’t a bad recommendation it is definitely not a necessity for everyone.
Myth 4: Reading In Dim Light Ruins Your Eyes
Reading in dim light is supposed to be bad for you, which is reflected by the existence of the bedside lamp and book light industries. You’ve almost certainly been told to turn on a light when reading in the near-dark. While reading without sufficient lighting can cause eye strain, according to children’s health researcher Rachel C. Vreeman and assistant professor of pediatrics Aaron E. Carrol it won’t cause any serious and permanent damage:
The majority consensus in ophthalmology, as outlined in a collection of educational material for patients, is that reading in dim light does not damage your eyes. Although it can cause eye strain with multiple temporary negative effects, it is unlikely to cause a permanent change on the function or structure of the eyes. Even in patients with Sjögren’s syndrome (an autoimmune disease that features inflammation in certain glands of the body), decreased functional visual acuity associated with strained reading improves when they stop reading. One review article on myopia concludes that increased use of one’s eyes, such as reading in dim light or holding books too close to the face, could result in impaired ocular growth and refractive error. The primary evidence cited was epidemiological evidence of the increased prevalence of myopia and the high incidence of myopia in people with more academic experience. The author notes that this hypothesis is just beginning to “gain scientific credence.” In the past reading conditions involved even less light, relying on candles or lanterns, so increased rates of myopia over the past several centuries does not necessarily support that dim reading conditions are to blame. In contrast to that review, hundreds of online expert opinions conclude that reading in low light does not hurt your eyes.
For more information on the studies mentioned above, read this.
Myth 5: Urinating On A Jellyfish Sting Will Sooth the Pain
The popular TV show Friends once featured an episode where Monica was stung by a jellyfish and Joey remembered that urinating on the sting would soothe the pain. This was a situation for comedy — the show was a sitcom, after all — but it still helped to propagate the myth that peeing on your friends is a good idea during the right situation. It’s not. Dr. Mark Leyner and Dr. Billy Goldberg, authors of Why Do Men Have Nipples?, explain:
The following guideline can be applied to most jellyfish stings: The patient should remove any visible tentacles, using gloves if possible. The area of the sting should be rinsed with household vinegar. The acetic acid of the vinegar can block discharge of the remaining nematocysts (stinging cells) on the skin and should be applied liberally. If vinegar is not available, salt water can be used to wash off the nematocysts. In laboratory tests, urine, ammonia, and alcohol can cause active stinging cells to fire, which means applying them has the potential to make a minor sting worse, so urinating on a jellyfish sting is both gross and painful.
So if you’re going to pee anyone, make sure it’s for your mutual enjoyment. Jellyfish are not a good excuse.
Myth 6: Your Slow Metabolism Makes You Fat
When you have a fast metabolism, your body is burning more calories. That means that fit and healthy people have faster metabolisms, right? Not necessarily. ABC News interviewed Dr. Jim Levine, an obesity researcher at the Mayo Clinic, who studied the human metabolism in both thin and heavy people. What he found was the opposite of the myth we believe. Referring to lean patient Kathy Strickland and heavier patient Dawn Campion, he said:
Dawn’s numbers are actually higher because we find continuously is that people with weight problems who have obesity have a higher basal metabolism compared to people who are lean. Your basal metabolism is the calories you burn to keep your body going, so if your body is bigger of course your basal metabolism is greater. If your body is smaller your basal metabolism is less.
Dr. Levin inferred that the weight problems in his patients was due to their sedentary lifestyles. That is, of course, only one part of the equation. Gaining unwanted weight can stem from an unhealthy diet, lack of exercise, and a number of other problems as well. It’s a complicated problem, and your metabolism isn’t necessarily to blame.
Myth 7: You’ll Catch A Cold From Cold (And Wet) Weather Conditions
Did your mother ever tell you to put on a jacket or you’ll catch a cold? Did you ever feel like you were coming down with something nasty after taking a dip in cold water only to be exposed to freezing air? While your comfort levels may have been reduced, you can’t actually catch a cold from feeling cold. It’s a virus — rhinovirus, to be exact — and you need to catch it through transmission. Dr. Mark Leyner and Dr. Billy Goldberg, authors of the book Why Do Men Have Nipples?, explain:
Cold or wet weather does not cause a cold, but nobody seems to want to accept this. The is common cold is caused by a virus. These viruses are everywhere and it is difficult to avoid them. When you are exposed to someone who has a cold, you are more likely to get ill yourself, so be careful about close contact and definitely wash your hands. Not getting enough sleep or eating poorly can also reduce your resistance to infection. Remember that antibiotics won’t fight your everyday cold. Antibiotics work only against bacteria. To take care of a cold, rest, eat well, and a little chicken soup couldn’t hurt.
But if that’s true, why do people contract a cold more often in the winter? Doctors don’t have a certain answer, but according to the New York Times there are a few working theories. Because colds are spread by transferring the virus from one person to another, you need to be in contact with other people. People spend more time indoors during the winter, and so you often find yourselves 1) around them, and 2) in an enclosed space. If one person gets sick in a household, office, or wherever, there’s a good chance that virus will spread. As you should any time of year, keep your distance from the contagious.
Myth 8: More Heat Escapes Through Your Head
Heat rises, and your head is generally warm, so it would stand to reason that walking around outside with your head uncovered isn’t the best plan if you want to stay nice and toasty. While that idea seems to make sense, it’s actually untrue. According to Children’s health researcher Rachel C. Vreeman and assistant professor of pediatrics Aaron E. Carrol, wearing a hat will just keep your head warmer:
This myth probably originated with an old military study in which scientists put subjects in arctic survival suits (but no hats) and measured their heat loss in extremely cold temperatures. Because it was the only part of the subjects’ bodies that was exposed to the cold, they lost the most heat through their heads. Experts say, however, that had this experiment been performed with subjects wearing only swimsuits, they would not have lost more than 10% of their body heat through their heads. A more recent study confirms that there is nothing special about the head and heat loss. Any uncovered part of the body loses heat and will reduce the core body temperature proportionally. So, if it is cold outside, you should protect your body. But whether you want to keep your head covered or not is up to you.
For more information on the studies mentioned, read this.
Myth 9: High Cholesterol Causes Heart Disease
Until writing this article, I believed high cholesterol was the primary contributing factor towards heart disease. It’s been a myth I’ve been told my entire life because I’m prone to cholesterol problems and have watched my levels very carefully since I was a child. According to Dr. Chris Kresser, and many others, there is no data actually pointing to this conclusion. It seems the real culprit is high blood pressure, and cholesterol problems may have found themselves grouped in because the two issues often appeared together. This doesn’t mean you want higher levels of cholesterol (with the exception of your LDls), but that if you’re worrying about a heart attack it’s not the first sign of trouble.
Myth 10: It’s Dangerous To Wake A Sleepwalker
It’s actually dangerous to not wake a sleepwalker, but many have believed this myth for ages because, perhaps, a few of them have gotten smacked when they woke up their startled somnambulatory friends. Sleepwalkers are certainly prone to feeling that surprise when they don’t wake up in their beds but, rather, at the outer limits of their camping grounds. (Oh wait, that was me when I was 10.) Because this is so disorienting, many woken sleepwalkers won’t know who you are and become frightened. That said, letting them just walk wherever they want is far less safe than a little fear. The New York Times interviewed Dr. Ana C. Krieger, director of the Sleep Disorders centre at New York University, who suggested that the best thing to do is guide a sleepwalker back to bed. Wake them if you have to, but better to just help them get to where they should be in the first place.
This story has been updated since its original publication.
Comments
16 responses to “10 Stubborn Body Myths Debunked By Science”
what about spot reduction!!!!
And what about spot reduction are you proposing?
I don’t agree with ‘Myth’ 7.
Although you do actually need to come in contact with a virus to catch the common cold, it is my belief (and experience) that being exposed to cold temperatures for prolonged periods of time does indeed increase the likelihood of catching that virus.
Maintaining ones immune system requires energy. During periods where we are cold and shivering our body is consuming greater amounts of energy in attempt to generate heat and stay warm. As such other energy dependent body processes, such as operating an effective immune system, may operate less efficiently during these periods.
We continually come into contact with virus particles (virions) throughout any given day, but an efficient immune system ensures that the vast majority of these viruses never have the chance to take hold. During periods of compromised immunity however, the virus has a greater chance of establishing an infection and causing a cold.
I for one know that the only time I ever get sick is if I awake to find myself cold. At that point I awake with an already sore throat (which is caused by a rhinovirus infecting and lysing the epithelial cells of my throat), and the common cold ensues from there.
I think it’s totally possible to be exposed to cold weather and never get sick so long as you stay warm
But what this article is saying is that you cant get a cold from being cold, the myth itself has nothing to do with the immune system. If you were placed in a room by yourself which was 0 degrees Celsius, you wouldn’t get a cold. Yes, your immune system may be a little weaker when in colder temperatures, but the mere fact that you are cold doesn’t mean you will get a cold for sure.
There is some evidence that getting cold increases your risk of acquiring a cold:
http://news.bbc.co.uk/2/hi/uk_news/wales/4433496.stm
Not all Jellyfish have vinegar as the treatment.
Bluebottles for example, should be treated with hot water.:
http://www.ambulance.nsw.gov.au/Media/docs/090730bluebottle-eee3bc83-ce7c-4281-a095-b427eb01e6d0-0.pdf
I disagree with myth 9. High cholesterol blocks the pipes; high blood pressure bursts the pipes. Coronary heart disease is the death of muscle in the heart due to lack of oxygen going through the pipes coz the pipes are too narrow. Eating less fatty food with decrease your low density cholesterol which is the bad cholesterol that hangs around in your blood stream and cause narrowing.
Is there really a proven link between dietary cholesterol and blood cholesterol?
Short answer: yes.
How? read…
http://books.google.com.au/books?id=rsoGth4pzNEC&lpg=PA36&dq=ldl%20cholesterol%20diet%20nutrition&pg=PA36#v=onepage&q=ldl%20cholesterol%20diet%20nutrition&f=false
not convinced?
Flora Proactiv website have lots of journal articles showing this link between dietary chol. and LDL/HDL in your blood.
http://www.floraloveyourheart.com.au/Consumer/FooterArticle.aspx?Path=Common/Footer/FooterArticles/ResearchStudiesandReferences
Gary Taubes is controversial in his approach, I won’t bet my life on that.
Cold weather can increase the incidence of chest infection. After an initial viral insult there are often secondary bacterial infections such as bordetella that complicate the disease- hence the antibiotics. These are cleared by alveolar macrophages within the body, but the phagocytosing ability of alveolar macrophages is decreased in cold weather- so colds become worse.
Myth 7: You’ll Catch A Cold From Cold (And Wet) Weather Conditions
Of course you do. It is silly to say otherwise…unless you want to be pedantic for the sake of being pedantic. Another case where some desperate scienctist tries to justify how great they are by disproving an old wives tale. Obviously your imune system is weakened & you are ‘extremely’ likely to catch that cold. It is logical, it is proven, it will happen again & again. Get over it and prove something useful. (from someone who has a science degree).
CN: Sorry, you’re misguided in your statement that eating less fatty food with (sic) decrease your low density cholesterol. Have a read of Why We Get Fat: And What To Do About it by Gary Taubes. An eye-opening read.
Myth 9: its actually High Density Lipoprotein (HDL) that you want high levels of. The actual protective value of a high HDL level is somewhat contentious as recent studies into Niacin and its HDL elevating properties have shown. Ischaemic Heart Disease (IHD) is complex and multifactorial. Cholesterol plaque formation starts at an early age, the oxidative damage that happens in a hypertensive environment coupled with micro-inflammation causes the eventual evolution of plaques to atheroma. It is very rarely the atheroma completely blocking off the coronary artery that is the cause of an Acute Coronary Syndrome event or MI. Atheroma eruption and subsequent clot formation at the site are more often the cause of and ACS event. Angina however can be due to low(er) level atheroma blockages and the mismatch between oxygen supply and demand vis-a-vis blood supply and the over taxed heart.
The way Myth 2 was presented was a bit disingenuous. The valid point was that there is more to good nutrition than a low calorie intake, but it was presented along the populist lines of ‘there is some sort of magic combination of foods that will cause you to lose weight, whilst not reducing calories at all’.
“While consuming fewer calories can certainly have an impact”??? In fact, creating a calorie deficit through exercise or calorie reduction is the only thing that will have an impact in terms of weight loss.
Myth 9 shouldn’t even be listed if you’re going to quote someone like Chris Kresser.
Mr Kresser also doesn’t believe UV radiation is bad for you or that it causes cancer. And encourages people to stop using sunscreen and stop worrying about the rays.
Mind you he’s careful to point out that prolonged sun exposure is not recommended….hmm I wonder why since the rays are so good? Surely it couldn’t be that he’s covering his own backside from any potential lawsuits?
Regardless of the differences in food, if your energy intake is above your energy output, you must gain weight.
If your energy output is higher than input, you must lose weight.
It is literally impossible for this to be otherwise, thanks to the laws of physics.
Chris Kresser is not an MD.