There’s something about health and nutrition folk wisdom that’s resistant to truth.
Common health “facts” include the ideas that MSG will make you sick, that a juice detox is just what you need after a week of indulgence, and that sports drinks like Gatorade are totally fine since you need the electrolytes.
None of these things are true. They, like many other folk sayings and tips, fall into the category of health myths that are totally — or at least mostly — wrong.
Here’s the truth behind some of those health claims you’ve heard all your life, but might not hold water at all.
The myth that MSG is bad for you comes from a letter a doctor wrote to the New England Journal of Medicine in 1968, where he coined the term 'Chinese restaurant syndrome' to describe a variety of symptoms including numbness and general weakness.
But though the doctor blamed these feelings on monosodium glutamate, MSG, the research doesn't back it up. The scientific consensus according the American Chemical Society is that 'MSG can temporarily affect a select few when consumed in huge quantities on an empty stomach, but it's perfectly safe for the vast majority of people.'
And this makes sense -- MSG is nothing more than a common amino acid with a sodium atom added. The placebo effect is more than strong enough to account for the negative effects sometimes associated with MSG.
There isn't a whole lot of evidence on this, but most research finds no correlation between caffeine consumption and bone growth in kids.
In adults, researchers have seen that increased caffeine consumption can very slightly limit calcium absorption, but the impact is so small that a tablespoon of milk will more than adequately offset the effects of a cup of coffee.
Interestingly, advertising seems to be largely responsible for this myth. A breakfast cereal manufacturer named C.W. Post was trying to market a morning beverage called 'Postum' as an alternative to coffee, so he ran ads on the 'evils' of Americans' favourite hot beverage, calling it a 'nerve poison' that should never be served to children.
Being physically cold isn't what gets you sick; exposure to a cold virus does. There's no evidence that going outside with wet hair when it's freezing will make you sick by itself -- provided you avoid hypothermia.
But there are some scientifically sound explanations for why people catch more colds in winter. Because we spend more time in close quarters indoors, it is more likely that we'll cross paths with a cold-causing virus spread from another person during the winter. And for several reasons, we may have a harder time fighting off cold and flu virus particles in winter.
But being cold itself isn't what makes sick, and some argue that cold exposure can actually improve your health.
Who doesn't love the post-Thanksgiving nap? We frequently consider those naps inevitable, since turkey contains tryptophan, an amino acid that is a component of some of the brain chemicals that help you relax.
But plenty of foods contain tryptophan. Cheddar cheese has even more than turkey -- and cheddar is never pointed out as a sleep inducing food. Experts say that instead, the carbs, alcohol, and general size of the Turkey-day feast are the cause of those delicious holiday siestas.
Vitamins sound like a great idea. One pill that can provide you everything you need to be healthy!
If only they worked. After decades of research on vitamins, most reviews don't find any justification for our multivitamin habit, and in some cases, vitamins have actually been associated with an increased risk of various cancers. Malnourished people might benefit from some supplements, but most of us should just get our vitamins naturally from food.
We're all heard it: 'beer before liquor, never sicker; liquor before beer, you're in the clear.'
But while it's very true that overdoing it with booze might leave you praying to the porcelain gods, there's no need to place the blame on the order you consume the beverages in -- alcohol is alcohol, and too much of it will make anyone feel sick.
However, there are some strange ways this piece of advice can make sense. People who switch from beer to mixed drinks (with senses and judgment already dulled) may be less likely likely to monitor their alcohol consumption and thus drink more.
And some research shows that your body metabolizes mixed drinks faster than higher-concentration alcohol (a shot of whiskey, say). So adding liquor to a stomach-full of beer could, in theory, create a sort of mixed drink that would metabolize faster than one or the other on its own.
We'll call this one partly true, but chalk up the 'never sicker' part mostly to bad decision making.
Not necessarily. You lose body heat through anything uncovered, according to Dr. Aaron E. Carroll and Dr. Rachel C. Vreeman, authors of 'Don't Swallow Your Gum!: Myths, Half-Truths, and Outright Lies About Your Body and Health.'
Your head is not special in that way -- it's just more likely to be exposed.
'Most of the time when we're outside in the cold, we're clothed,' Richard Ingebretsen, MD, PhD, told WebMD Magazine. 'If you don't have a hat on, you lose heat through your head, just as you would lose heat through your legs if you were wearing shorts.'
Some parents say no swimming for 30 minutes after eating, some say an hour, but many of us may remember waiting out the clock before returning to the pool or beach. The theory behind this seems to be that digesting food will draw blood to your stomach, meaning that less blood is available for your muscles, making them more likely to cramp.
Cramps do happen frequently when swimming, but they aren't caused by what's in your stomach. If you do get one, the best policy is to float for a minute and let it pass.
First of all, your body naturally removes harmful chemicals through the liver, kidneys, and gastrointestinal tract -- there's nothing about juice that will hurry that process along.
Secondly, juicing is mostly a way of removing helpful fibre from fruits and vegetables -- many sugary fruit juices are as bad for you as sodas. You're making the fruit less healthy by 'juicing' it.
It's the worst when something you really wanted to eat falls on the floor. But if you grab it in five seconds, is it ok?
Sorry, but the five-second-rule isn't a real thing. Bacteria can contaminate a food within milliseconds. Moist foods attract more bacteria than dry foods, but there's no 'safe duration.' Instead, safety depends on how clean the surface you dropped the food on is.
Whether you eat it or not after that is up to you, but if the people that walk on that floor are also walking around New York City, for example, we wouldn't recommend it.
It turned out that study wasn't only flawed, it also contained false information that was necessary to make its point.
Since then, numerous studies that have analysed data from more than a million children have shown that there's no connection between vaccines and autism.
But fears about that connection have persisted, partially spurred on by public figures making false claims about vaccines. This has led to scary diseases like measles coming back.
This is one of our modern health myths. Yogurt is frequently marketed as having benefits for digestion and as something that will keep people slim because of probiotics, or the 'good bacteria' that's living inside it.
Researchers have found that the bacteria in our bodies are very connected to our metabolism and obesity rates, among other things, so it seems like there's a logical connection here.
But we don't yet understand how the trillions of bacteria in our bodies work well enough to manipulate them in this way. Despite the fact that the probiotic business was worth $US23.1 billion in 2012, we can't make yogurt that will repair our inner bacterial balance.
That's not to say that yogurt is unhealthy, just that its benefits are oversold. Plus, a lot of yogurt is packed with sugar, which we do know contributes to obesity and other problems -- so if you enjoy yogurt, find a version that isn't full of additional unnecessary calories or it might have the opposite of the intended effect.
Apples are good for you, packed with vitamin C and fibre, both of which are important to long-term health, but they aren't all you need.
And if certain viruses or bacteria get into your system, an apple will unfortunately do nothing to protect you. So go ahead and get that flu shot, even if you eat apples.
If you're home sick with a cold, you can totally go ahead and comfort yourself with some ice cream.
The idea that dairy increases mucus production is very fortunately not true, according to researchers and a doctor at the Mayo Clinic, who says 'in fact, frozen dairy products can soothe a sore throat and provide calories when you otherwise may not eat.'
Fortunately, this isn't true either.
Cracking your knuckles may annoy the people around you, but even people who have done it frequently for many years aren't any more likely to develop arthritis than those who don't.
There's a good reason you may have heard this said multiple ways, either 'starve a cold, feed a fever' or 'starve a fever, feed a cold.'
Despite a slew of headlines claiming that starving a fever wasn't a myth in response to a tiny and largely misinterpreted study in 2002, there's no real evidence to back this up. Limiting your caloric consumption may actually hurt your immune system more than helping it, and it would certainly be a bad idea to not eat during the 6-8 day duration of a cold.
Instead, doctors say to go ahead and eat if you can. The more accurate expression, as Scientific American notes, would be 'feed a cold, feed a fever.' And make sure to get plenty of fluids.
In sufficient quantities, caffeine and alcohol can have a diuretic effect. But the amount of caffeine in a typical cup of coffee or alcohol in a beer isn't enough to really have this effect, according to one recent study. A moderate amount of either coffee or beer hydrates people just about as well as water does.
This is an incredibly successful bit of advertising that has wormed its way into our brains and policies -- the US Department of Agriculture tells us that adults should drink three cups of milk a day, mostly for calcium and vitamin D.
Milk is fine, but it's not a magical health drink. Surprisingly, however, milk is particularly hydrating -- similar to pedialyte, both even more hydrating than water.
The tide has started to swing back the other way on this one, but recommendations for low-fat foods remain common.
The decision to demonize fat for its caloric density and heart-clogging effects was largely the result of shady science influenced by a sugar trade group. It turns out that the society-wide decision to cut saturated fat from diets led to increased consumption of sugar and processed trans fats, all of which were most likely less healthy overall.
We need a moderate amount of fat -- especially healthy fat -- in our diets.
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