9 Internet Nutrition Myths that Just Won't Go Away

Are you being duped by what you're reading on the web?
Are you being duped by what you're reading on the web?

By Julie Upton, RD, Prevention

The Internet has many gifts to offer. Prevention.com (obviously), the ability to shop online for curtains at any hour, access to breaking medical news, and an endless supply of cat videos, just to name a few. But it also offers up some ridiculous myths--particularly in the realm of nutrition--that are more stubborn than an oil stain. But enough already. Here, 9 of the more dubious nutrition myths you'll find online--busted.

PLUS: Check out these 25 Best Weight-Loss Tips Of All Time for painless ideas that actually work.

Myth: Microwaves destroy essential nutrients in foods
You've probably heard that microwaves rob food of its nutritional value, but that's just not true. Research reviews that compare microwaving food to traditional cooking methods reveal minimal differences. And, in some cases, microwaving may help retain more of specific nutrients, such as water-soluble nutrients that are generally lost when steaming.

When food is heated--whether from an oven, stovetop, grill, or microwave--there will be some level of nutrient degradation. The losses generally stem from nutrients that aren't heat-stable, like vitamin C and some phytonutrients. In addition, many nutrients are water-soluble, which means that they will leach into any cooking liquid that you may use. To retain the most nutrition in your foods (regardless of the method used) avoid using extremely high temperatures, don't over-cook food, and use as little water or liquid as possible.

Myth: Cancer cells feed on sugar
Fact: One of the most widespread Internet hoaxes is an email chain entitled, "Cancer Update from John Hopkins." The chain letter details alternative ways to avoid and treat cancer that claim to be more effective than chemotherapy, radiation, or surgery. It's been around since 2007, and has been so widely distributed that the National Cancer Institute and American Cancer Society are still getting questions about it. And while the email chain letter states that cancers "feed" on certain foods like sugars, the fact is, the only connection added sugars have to cancer is that they're likely to contribute to weight gain, which is a risk factor for many types of cancer.

The National Cancer Institute and the American Cancer Society recommend a plant-based diet rich in fruits and vegetables, whole grains, beans, and nuts. They also recommend limiting added sugars from sodas, desserts, and other nutrient-poor choices, as a way of stopping the spread of your waistline, not cancer cells.

PLUS: Learn the 57 Sneaky Names Sugar Goes By.

Myth: Vegetarian diets change your body chemistry to make you slim

The myth goes like this: Vegetarian diets make your body more alkaline (higher pH), thus helping you lose weight. But that science just doesn't hold up. If you recall high school chemistry, you'll know that pH is the measure of acidity and alkalinity. A pH of 0 is completely acidic, a pH of 14 is completely alkaline, and a pH of 7 is neutral. Many suspect online sources claim that much of what ails us stems from a diet rich in added sugars, processed food, and excess meats, which all make our blood and body too acidic. Therefore, the thinking follows, a diet rich in "alkalinizing" foods like fruits and veggies will balance your pH and help you lose weight.

The problem with this premise: No matter what you eat, the body has several mechanisms to ensure that your pH levels are highly controlled. For example, the stomach has a pH ranging from 1.35-3.5. It must be acidic to aid in digestion. However, blood must always be slightly alkaline, with a pH of 7.35 to 7.45. The pH of your blood is so tightly regulated that if it falls only slightly below or above what's normal (like with kidney failure), death would result. Bottom line: What you eat might impact the pH of your urine, but it won't impact the pH of your blood or tissues. (Surprisingly, your urine reveals a ton about your disease risk and what's actually going on in your body. Find out what your urine can tell you about your health.)

Myth: You need to "cleanse" to detox your body

If you Google "detox diet," you'll get nearly 23 million results for diet programs and treatments that are supposed to help "flush out your system," "reboot your body," "rest your GI tract," or "cleanse your liver and kidneys of harmful toxins." Celebrities, trainers, and other so-called experts often suggest "detoxing" or "cleansing" once or twice a year to feel your best. But despite all the hype and popularity, there's little proof that fasting or following a deprivation diet for several days will result in anything more than making yourself completely miserable.

As far as detoxifying your system, that's what your GI tract, liver, and kidneys are designed to do. And they're quite good at it, thank you very much. Oh, and the weight loss you might see when you cleanse, e.g., give up up sugar, alcohol, caffeine, processed foods, and pretty much everything else? As soon as you go back to eating a normal diet, the weight will come right back. If you really want to improve your health, drink a lot of water (try these 25 sassy water recipes to keep things fresh and interesting), eat a diet rich in plant-based foods, limit added sugars and saturated fats, and get plenty of sleep and exercise.

PLUS: 9 Essentials Of a Diet Detox

Myth: Canola oil is produced from the toxic rapeseed plant
Canola oil comes from the crushed seeds of canola plants, not rapeseeds. And while the two plants are cousins, they're distinctly different--nutritionally and compositionally. Rapeseed oil naturally contains high levels of erucic acid, which is linked to heart disease, and therefore is not allowed to be sold in the U.S. In the 1960s, farmers used breeding methods to help eliminate the erucic acid from canola plants, and canola oil is now regulated to have less than 2% of erucic acid. In other words, canola oil is not toxic. Plus, it also happens to be one of the heart-healthiest oils, because it has less saturated fat and more omega-3s than other vegetable oils.

LEARN MORE: The Best Oil For Every Cooking Method

Myth: Sea salt is healthier than table salt
Marketers of sea salt want you to think you're paying a premium for a nutritionally superior product. Not so much. The truth is, regular table salt and gourmet sea salt contain essentially the same amount of sodium--2,300 milligrams per teaspoon (the daily recommended limit for adults up to 50 years old; those older than 50 are advised to limit sodium to no more than 1,500 mg per day). And, when it comes to the minerals that are present in sea salt, such as calcium and potassium, there's not much to get excited about: Most sea salts provide 1 to 2% of the daily calcium or potassium you need, and it's certainly not the way you want to try to meet your mineral requirements. Sea salt also lacks iodine, an essential mineral that your thyroid needs.

Bottom line: Sea salt differs in taste and texture, which means you may use less of it--but choosing it for "nutritional superiority" just doesn't make sense.

Myth: You use more calories eating certain foods than you take in

When something sounds too good to be true...well, you know how it goes. A "negative-calorie food"--while sounding awesome--simply doesn't exist. The myth stems from the notion that some foods require more energy to be digested than they provide, a term professionals call the "thermic effect of food," or the energy cost to digest it. Celery, lettuce, lemons, and limes are often misidentified as negative-calorie foods, but the thermic effect to digest these foods ranges from just 10 to 20% of its total calories. So, if a celery stalk has 7 calories and it takes 20% of those calories to digest it, you still have a net energy gain of 5.5 calories.

DID YOU KNOW? The average person eats 580 calories a day in snacks? Click here for 16 Ways To Curb Mindless Munching.

Myth: Margarine is one molecule away from being plastic
It's hard to know exactly where this myth started and why it keeps going, but it may be a product of the never-ending butter vs. margarine debate. Margarine and soft spreads are made when liquid vegetable oils undergo the process of hydrogenation (adding hydrogen atoms), which turns the liquid vegetable oil into a solid at room temperature. While the process is definitely less "natural" than butter (which is made by churning cream), it doesn't mean margarine is anything like plastic. The reason why margarines are less likely to spoil is because vegetable oils are shelf-stable and don't go rancid quickly compared to dairy products that spoil without refrigeration.

In the past, margarines did get a bad rap for having trans fats, but most brands have eliminated harmful trans fats from their products. While the calories of butter and margarine are the same, the potential health benefit of margarine is that it has significantly less saturated fat than butter and it's cholesterol-free. Margarine and soft spreads have a role for many individuals who try to meet American Heart Association guidelines for limiting saturated fat to no more than 7% of total calories, or about 15 grams per 2,000-calorie diet. According to the USDA nutrient database, a tablespoon of butter has 7 grams of saturated fat compared to 2 grams in a soft spread. If your overall diet is low in saturated fat and you don't have any other risk for heart disease, butter is fine to enjoy in moderation.

While dieting can definitely help you reach your ideal body weight, make sure not to ditch these 7 supposedly "forbidden" foods that actually help you lose weight.

Myth: Skim milk is more fattening than whole milk
Is it a full-fat paradox: Drinking skim milk may contribute to weight gain while whole milk helps you lose weight? This misinformation is more half-truths, because some population-based studies have reported associations between full-fat dairy consumption and lower body weight. But there's a lot more to the story. When it comes to weight gain, your total calories and the quality of those calories is what matters. In fact, a review article of all the randomized human clinical trials about dairy and weight, reported in the peer-review journal PLoS One, found that simply adding either low-fat or full-fat dairy foods will increase body weight, and only when dairy is included as part of a calorie-restricted diet will it play a role in weight loss. Since skim milk is a nutrient-rich choice, and has no added sugars, it can be included as part of a calorie-reduced diet to aid in weight loss. If you choose whole milk--one cup of whole milk has 149 calories and 8 g fat, compared to skim's 83 calories and less than .5 g fat--and are trying to lose weight, you'll need to account for its calories, plain and simple.

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