10 Stubborn Food Myths That Just Won't Die, Debunked by Science
-
Upload
krreation7086 -
Category
Documents
-
view
215 -
download
0
description
Transcript of 10 Stubborn Food Myths That Just Won't Die, Debunked by Science
10 Stubborn Food Myths That Just Won't Die, Debunked
by Science
Every other week, new research claims one food is better than another, or that some ingredient
yields incredible new health benefits. Couple that with a few old wives' tales passed down from
your parents, and each time you fire up your stove or sit down to eat a healthy meal, it can be
difficult separating food fact from fiction. We talked to a group of nutritionists and asked them to
share the food myths they find most irritating and explain why people cling to them. Here's what
they said.
Image remixed using a photo by Alex Galt.
Myth 1: Never Use Wooden Cutting Boards with Meat
This rule, one that I myself have repeated, comes from the notion that using a wooden cutting
board will result in tiny scratches and cuts from your knife, and if you use that cutting board with
meat-especially raw meat-that all those meat juices will settle into those tiny cuts in the board, and
no matter how much you scrub, those germs aren't coming out. The point has even been made
by people as esteemed as Alton Brown. The solution is to use plastic cutting boards, which can be
dishwashed and sanitized, and therefore must be safer, right?
Unfortunately, there's a great deal of research that disputes this notion. One of the most famous
studies was conducted at the University of California: Davis, by Dean O. Cliver, Ph.D of the UC-
Davis Food Safety Laboratory. His research points out that there's no significant antibacterial
benefit from using a plastic cutting board over a wood one. He notes that even if you apply
bacteria to a wooden cutting board, its natural properties cause the bacteria to pass through the
top layer of the wood and settle inside, where they're very difficult to bring out unless you split the
board open.
Although the bacteria that have disappeared from the wood surfaces are found alive
inside the wood for some time after application, they evidently do not multiply, and they
gradually die. They can be detected only by splitting or gouging the wood or by forcing
water completely through from one surface to the other. If a sharp knife is used to cut
into the work surfaces after used plastic or wood has been contaminated with bacteria
and cleaned manually, more bacteria are recovered from a used plastic surface than
from a used wood surface.
Dr. Cliver's study tested 10 different hardwoods and 4 different plastic polymers. In the end, the
result was a very scientific one: if you want a plastic cutting board, anti-bacterial properties is no
reason to buy one. If you want a wooden cutting board, bacterial infection shouldn't scare you
away. Which is better? That's a different discussion, but ultimately it's more important that you take
care to properly clean and disinfect whatever board you buy, regardless of what it's made of. Oh,
and don't fall for plastic or other cutting boards that tout themselves as being coated or made
with anti-microbial chemicals or materials, that's largely junk science as well. Photo by Jarrod
Lombardo.
Myth 2: Adding Salt to Water Changes the Boiling Point, Cooks Food
Faster This is one of those food myths that doesn't want to die. You'll hear it repeated by home cooks and
professional chefs, but any first year Chemistry student (or in my case, a Physics student taking
Applied Thermodynamics) will be able to show you how little the amount of salt you would add to
a pot of boiling water in your kitchen actually alters the boiling point.
Yes, strictly speaking, adding salt to water will alter the boiling point, but the concentration of salt
dissolved in the water is directly related to the increase in the boiling point. In order to change
water's boiling point appreciably, you would have to add so much table salt (and dissolve it
completely) that the resulting salt water would be nearly inedible. In fact, the amount of salt you're
likely to add to a pot of water will only alter the boiling point of water by a few tenths of a degree
Celsius at most.
So this is one of those food myths that rings of chemical truth, but only on scales that wouldn't be
applicable for cooking. One thing is for sure though, adding salt to your pasta water definitely
makes the resulting pasta tasty.
Myth 3: Low Fat Foods Are Always Better For You
Alannah DiBona, a Boston based nutritionist and wellness counselor made this her number one
food myth. She said:
"Without fat, the human body is unable to absorb a large percentage of the nutrients needed
to survive. Additionally, fat deprivation prevents messages from being passed between
neurotransmitters, resulting in all kinds of neural misfiring in the body! While good fats and bad
fats do exist, the right fats in the proper amounts can actually aid in weight loss and
cholesterol management."
The high-fat/low-fat food myth is one that's been around for a long, long time. Ultimately, it's more
important to flip over the food you're about to buy and read the label, see what kinds of fats are in
it, and then make an educated decision instead of immediately reaching for the low-fat version of
whatever it is you're planning to buy, thinking it'll be healthier. In fact, many products that are "low-
fat" are low in good fats as opposed to the bad ones, or substitute in other ingredients like sugars
and sodium that you don't want more of in your diet.
Seattle-based Registered Dietitian Andy Bellatti also called out this particular myth. He said, "A
good intake of healthful fats is beneficial for cardiovascular health. Prioritize monounsaturated fats
(avocados, olives, pecans, almonds, peanuts) and omega-3 fatty acids (hemp seeds, chia seeds,
sea vegetables, wild salmon). Virgin coconut oil and dark chocolate (80% cocoa or higher) also
offer healthful fatty acids. Many low-fat diets are high in sugar and refined carbohydrates (i.e.:
white flour), which are increasingly becoming linked to increased rates of heart disease." Photo by
Bradley Gordon.
Myth 4: Dairy Is The Best Thing For Healthy Bones
When I asked Andy Bellatti about the most stubborn food myths he's encountered, he noted that
too many people confuse "dairy" with "calcium," assume they're the same thing, and think that
dairy is the best thing for healthy and strong bones. He explained, "Dairy contains calcium, but so
do dark-leafy greens. Milk is fortified with vitamin D, just like all milk alternatives. Additionally, bone
health goes beyond calcium and vitamin D. Vitamin K is important for bone health (dark leafy
greens have it, dairy doesn't). Magnesium (present in foods like almonds, cashews, oatmeal, and
potatoes, but missing in dairy products) also plays an important role in bone health." Photo by
Quinn Dombrowski.
Ultimately, if you're concerned about bone health, you should make sure to get enough calcium
in your diet, and while milk and cheese are good sources of it, they're by no means the only
sources. It's important-and can be just as healthy-to branch out and make sure you're eating dark
leafy greens instead of just chugging down milk. Even the Harvard School of Public Health points
out that milk isn't the only, or even the best, source of calcium, as does the University of Missouri's
Nutrition "mythbusters." If you're looking for good sources of calcium and Vitamin D, consider
collard greens, mustard greens, kale, and bok choy instead of milk.
Myth 5: Everyone Should Drink 64-Ounces or 8 Glasses of Water Every
Day
This myth is a holdover from a poor attempt by a number of doctors who wanted to wage an ill-
researched campaign against sodas and sugary drinks. Their hearts were in the right place, but
the fact of the matter is that there's no uniform rule for how much water a person should drink in a
given day. Alannah DiBona explains, "Water's been touted as the cure for all sins, and in some
ways, it's true—proper hydration is necessary for just about anything body and mind-related.
However, sixty-four ounces per day isn't going to always be the right number for you." Photo by
Michael McCullough.
My old nutritionist explained to me that I should try to drink my body weight in ounces of water,
divided in half. She noted that's a good guideline for most people, but also noted that it's a goal—
not a rule. When I asked her whether there would be real health benefits from it, she explained
that it's not going to make my body work better or somehow stave off disease magically, but it will
give me energy, prevent dehydration, get me up away from my desk and walking to the water
fountain, and she pointed out that often our bodies interpret thirst signals as hunger. It's anecdotal,
but I have to admit that drinking more water made me feel better by leaps and bounds.
While it's important to hydrate, it's not important to stick to an arbitrary rule defining how you
hydrate, or how much you drink, or even where you get it, although water is obviously the best
source of, well, water. "Nutrition is an individual science, and there will be days when your body
and mind require less than the average recommendation," DiBona explains. "Remember that
water is available to you through all liquids, fruits, and vegetables, and that the mark of proper
hydration is very light yellow-colored urine."
Myth 6: High-Sodium Foods Taste Salty, So Avoid Salty Snacks
Andy Belatti pointed this one out when we spoke, and it's especially important for people who are
managing their salt and sodium intake because they're at risk for hypertension or diabetes. While
new research indicates that low-sodium diets may not be better for your heart, they definitely
reduce your chances of high blood pressure or type II diabetes. The trouble with managing sodium
though, is that not all high-sodium foods taste salty when you eat them.
"While surface salt (the type on pretzels and salted nuts) is noticeable, stealth sodium (that which is
added during processing) is harder to taste. This is why many people don't realize that a Dunkin'
Donuts corn muffin contains as much sodium as 9 McDonald's Chicken McNuggets," Belatti
explains.
This fact is a testament to the importance of reading nutrition labels when you grocery shop, and
why it's important to look up nutrition information for your favorite foods at restaurants or fast-food
eateries either on the web or in-store when you're out for lunch or dinner. Sodium can lurk in
strange and surprising places. Check out the National Heart, Lung, and Blood Institute (at the NIH)
for more tips on reducing your sodium intake, and what to watch out for.
Myth 7: Eating Eggs Will Jack Up Your Cholesterol
A number of you took me to task on this one the last time I insinuated that eggs may not be
healthy, and rightfully so. Alannah Dibona cleared this one up once and for all, and notes: "More
often than not, a person diagnosed with high cholesterol will go out of his or her way to avoid
eggs, which is really unnecessary. The body's cholesterol levels are influenced by certain saturated
and trans fats; eggs contain very little saturated fat (1.5 grams of fat per large egg) and absolutely
no trans fat. Depriving yourself of an egg means foregoing 13 naturally occurring vitamins and
minerals (and a really delicious breakfast option)." Photo by Olaf Gradin.
Ultimately, eliminating eggs from your diet because you're concerned about cholesterol will do
absolutely nothing for you, and instead may actually be harmful because you're missing out on
the health benefits they have. The Harvard Medical School agrees, as does the Mayo Clinic,
although they take a more metered approach to the issue, and suggest that if you love eggs, eat
the whites and not the yolks. Both agree that even though the yolks have a lot of cholesterol, very
little of it actually makes it into your bloodstream, where it matters.
Myth 8: Searing Meat Seals In Juices 19th century German chemist Justus von Liebig was one of the first people to propose that by
applying very high temperatures to meat you would create a "sealed" layer of cooked meat
through which liquid inside the meat couldn't escape. Ever since then, the mantra has been
repeated over and over again, specifically in reference to dry heating cuts of raw meat. Photo by
Naotake Murayama.
The trouble is that Liebig's experiment compared the liquid and nutrients from a piece of meat
submerged in cold water which was gradually heated in that water and simmered in the cooking
liquid with a dry piece of meat applied to an extremely hot surface. When considered this way,
you can see why Liebig thought that searing meat "sealed in juices," because the resulting meat
was juicier than the meat that was essentially boiled to death.
However, in the book On Food and Cooking, Harold McGee finally makes a direct comparison
between a seared piece of meat and an un-seared piece, both cooked with identical methods.
The result was that the seared piece of meat actually retained fewer juices than the un-seared
piece, and at the very least the searing did nothing to preserve the moisture inside the meat.
This debate is still one that rages today. There are plenty of people who think that searing meat
does result in moister meat, while others dispute it. In reality, the best thing about searing meat is
that when applied to high heat, the surface of the meat undergoes the Maillard Reaction, which
results in some delicious browning on the surface of the meat. At the end of the day, you should
definitely sear your steaks—not because it "locks in juices," but because it's tasty.
Myth 9: Aluminum Foil and Cookware Is Linked to Alzheimer's Disease If you haven't heard this one in a while, good-it was repeated often in the late 80s and through the
90s, and even though it's fallen out of fashion (largely because it's just not true) there are still a lot
of people who believe it. This myth has its roots in research from the 1960s and 1970s that showed
elevated levels of aluminum in the brains of Alzheimer's patients. The hyperbole alarm was
subsequently sounded, and for years people were warned off of aluminum pots and pans, and
even aluminum foil to store food.
Since those studies however, a great deal of research has been done into what possible
connections aluminum may have with Alzheimer's Disease, and at best has failed to show any
substantive link or connection between aluminum and risk for Alzheimer's Disease. At worst there
have been conflicting results. Most experts at this stage believe any aluminum absorbed by the
body is processed by the kidneys and urinated out, and it does not pose a threat for Alzheimer's
Disease.
Myth 10: Don't Eat After 6/7/8PM Both Andy Belatti and Alannah DiBona called this myth out in different ways. Andy went right for its
throat, noting that it is "A silly weight-loss gimmick. What matters is what you're eating throughout
the day. Food eaten after 7 does not magically turn to fat. This is also a ridiculous 'tip' for someone
who goes to bed at midnight or 1 AM. This tip often 'works' because people end up reducing their
total caloric intake." Photo by Ishikawa Ken.
He's right: this myth comes from a half-scientific understanding of how digestion works. The idea is
that if you eat too late and go to bed on a full stomach, your body's metabolism will slow down
and instead of burning the food you just ate, you'll turn it all into fat and gain weight. That
statement is only partially true, and isn't universal for all people. While it's true your metabolism
slows down when you go to sleep, it doesn't stop, and you still churn through the food in your
stomach, albeit slower. If your diet, exercise, and activity habits mean that a meal is more likely to
metabolize into fat because you sit at a desk all day, eating it at 5pm versus 7pm isn't going to
change that.
In reality, what really happens for the people who swear by this trick is that they don't wind up
eating breakfast the following morning on top of a stomach full of food, and that they've blocked
off areas of their night when they're not consuming food-as opposed to someone who would be
tempted to have a late-night snack. In essence, they're just eating less overall. This myth is so
popular that the ADA has a page dedicated to debunking it.
Belatti also makes the point that if you're the type of person who's up very late, setting an arbitrary
time to stop eating at night isn't going to help you lose weight, it's just going to make you skip a
meal. DiBona had something specific to say about meal skipping, and how dangerous it can be:
"Just several years ago, I remember reading in Cosmopolitan magazine that skipping breakfast or
lunch following a "night of indulgence" could aid in one's efforts to lose weight. The editors couldn't
have been more wrong. If a meal is skipped, the body begins a process of metabolic slowing
commonly referred to as ‘starvation mode.'" She continued, "Additionally, surges of hormones then
encourage overeating at the next meal, resulting in a higher caloric intake at the day's end.
Keeping one's blood sugar balanced with small meals and snacks throughout the day is a much
more successful approach for weight maintenance and mental alertness."
Bonus Myth: Wine Has Health Benefits, Beer and Liquor Do Not Cheers, everyone: while studies outlining the health benefits of wine make for great headlines, it's
commonly accepted that in addition to the antioxidants in wine, all alcohols-when consumed in
moderate doses-can raise the body's levels of HDL, or the "good cholesterol." Alannah DiBona
explains: "Wine (as well as beer, liquors, and all types of alcohol) in moderate doses raise the
body's levels of HDL, or good cholesterol, which protects the heart against the plaque build up
that may cause strokes and heart attacks. As Europeans have proved for centuries, 1 to 2
alcoholic beverages per day helps to reduce the risks of heart disease."
While we're not going to tell you to go out and develop an alcohol problem in the name of good
heart health and lower cholesterol, a glass of wine or a couple of beers can actually reduce your
risk for heart disease when combined with a good diet and exercise. Just be careful of the calories
you intake when drinking alcohol-that bottle of wine or six-pack of beer isn't calorie-free, you
know.
How to Debunk Your Own Food Myths Some of the most persistent food myths are the ones that are considered common knowledge, or
the ones that have been long disproven but were trumpeted loudly when they were "discovered"
but never formally rebutted so much when they were debunked. If there's anything I learned in my
years as a scientist and a student, it was to always keep an open mind. Not so open that your
brains fall out, mind you, but open enough that you're willing to challenge your own deeply held
beliefs in the light of new evidence that contradicts them. Photo by emokson.
Keeping an open mind is only part of the battle however: you also need to seek out and pay
attention to reputable sources of information when you're reading about or researching food or
nutrition science. The Cleveland Clinic has an excellent guide to considering reputable sources on
the web. We also suggest checking up on food news and new research with the American
Dietetic Association, the US Department of Agriculture's Food and Nutrition Information Center,
and the US Department of Health and Human Services' Healthfinder.gov portal for reliable food
and health information. Also, don't ever hesitate to seek out peer-reviewed scientific studies and
research to prove or disprove a point.
It's all too easy on the internet to demand someone produce a study when they present an idea
you disagree with-it's another thing to look for it yourself, or to similarly concede when they do so,
instead of simply finding a new vector of attack.
One last note: common sense reigns king: if some tip or magical diet truism seems too good to be
true, or too simple to be uniformly true for all people, it probably is.
These myths just scratch the surface, and are only a few of the long lists of food myths that
Alannah Dibona and Andy Belatti suggested. There are plenty where these came from, and we
cover a lot of them here at Lifehacker when they come up. For example, our own Melanie Pinola
took note when research from the USDA showed alcohol doesn't "burn out" during cooking the
way many people think it did.
What are some of your favorite food myths that desperately need debunking? Share your
thoughts in the comments below.
Andy Bellatti, MS, RD is a Seattle-based Nutritionist and the author of the nutrition blog Small Bites.
You can follow him on Twitter at @andybellatti.
Alannah Dibona, MA, MS, is a Boston-based nutritionist and wellness counselor, and the woman
behind mindbodysportconsulting.com.
Both graciously volunteered their expertise for this story, and we thank them.
Pasted from <http://lifehacker.com/5847591/10-stubborn-food-myths-that-just-wont-die>