EVEN MORE Nutrition Myths—Busted!
Nutrition myths are like rolling snowballs.
They start from a state of small significance and quickly build upon themselves, becoming larger—and potentially dangerous—as they gain momentum. In many instances, nutrition beliefs that may have started from a kernel of truth become so warped by hearsay and the media that holding on to them may be detrimental to your health. Learn to separate fact from fiction with our newest edition of the truth behind nutrition myths and you can start losing weight and saving money today.
MYTH: Celery has negative calories.
The idea of “negative calorie” foods is sexy. It’s popular. It even sounds cool. Snacking on celery? Not so! I’m actually losing weight! The theory is simple: Some foods have so few calories that the act of chewing and digesting them requires more energy than the body absorbs, resulting in a calorie deficit that leads to weight loss. Topping the “negative” list is the humble celery stick. At only 10 calories, much of the vegetable’s caloric content is bound up in cellulose, a fiber that passes through the the system undigested. In reality, it only takes a little more than half a calorie to digest a stalk. Moreover, a study published in The American Journal of Clinical Nutrition suggests the thermic effect (the increase of metabolism after eating) may be even lower after high-fiber meals. Sure a celery stick is a wiser nutritional choice than say, a pretzel rod, but bottom line: if you’re eating, you’re consuming calories. And celery, or any other proclaimed “negative calorie” food isn’t a magic bullet for weight loss.
MYTH: Nutrition labels are always factual.
How many calories does a 100-calorie pack of mini Oreos have? The answer’s not obvious. Nutrition facts labels are mandated by the U.S. Food and Drug Administration (FDA) in accordance with the 1990 Nutrition Labeling and Education Act (NLEA). Unfortunately, they’re not always factual. In fact, the law allows a 20 percent margin of error for the stated value of calories and nutrients. In other words, your 100-calorie pack of mini Oreos could, theoretically (and legally), cost you 120 calories. One study in the journal Obesity that evaluated the “true” caloric content of 24 common food products found calories to be higher by an average of 4.3 percent. One popular snack’s carbohydrate content exceeded label statements by 7.7 percent according to the study. An investigative piece by the New York Times’ Calorie Detective found similar, unsettling results. Of the five everyday food items from chains like Subway, Starbucks and Chipotle that were sent a lab for testing, four had more calories than their labels reported—an excess adding up to 550 calories: enough to put on an extra pound of body weight in a week. Bottom line? Labels are a good guideline, but don’t obsess over calorie counting; if it sounds too good to be true, it probably is.
MYTH: Organic produce is more nutritious than conventional.
So you’re at the grocery store, and there they are: romaine hearts. They look great. And right next to them: organic romaine hearts. They look exactly the same, but they’re $1 more. Do organic fruits and vegetables actually provide a nutritional lift? Many naysayers will tell you “organic” is simply a marketing ploy and a wallet squeeze. A recent review in the British Journal of Nutrition did find substantially higher levels of antioxidants and lower levels of pesticides in organic produce compared with conventionally grown, but the study authors stop short of claiming that organic produce will lead to better health, and there are no peer-reviewed studies to support that claim. In fact, a similar well-cited analysis by Stanford scientists found very few differences in the nutritional content of organic and conventionally grown foods; the differences that do exist are so small, the authors say, that they’re unlikely to influence the health of the people who chose to buy (typically more expensive) organic foods. Bottom line for health experts? Buying organic fruits and vegetables may help you dodge pesticides (which can cause some tummy trouble), but there’s no convincing evidence (yet) that conventional and organic produce are different in nutritional composition.
MYTH: You should drink 8 fluid ounces of water, 8 times a day.
You’d be hard-pressed to find a diet book that didn’t tell you to guzzle water in order to stay healthy and lose weight. But experts are speaking out about the “8x8” rule—the theory that you should drink at least eight, eight-fluid-ounce glasses of water every day to prevent dehydration. The recommendation "is not only nonsense, but is thoroughly debunked nonsense," argues General Practitioner, Margaret McCartney in a British Medical Journal review. There is no benefit from drinking lots of water, she says. In fact, it may even be dangerous. A recent study in the British Journal of Sports Medicine that assessed a group of cyclists’ performance after rehydration found no performance difference between those that were fully rehydrated and a control group that got nothing. And a study in the New England Journal of Medicine, for example, found that close to one sixth of Boston Marathon runners developed some degree of hyponatremia, or dilution of the blood caused by drinking too much water. So where does the 8x8 myth come from? A review in the American Journal of Physiology by Heinz Valtin of Dartmouth Medical School suggests the idea may have started when the Food and Nutrition Board of the National Research Council recommended approximately "1 milliliter of water for each calorie of food," which adds up to 64 to 80 ounces. Widely ignored, however, is the Board’s next sentence: "most of this quantity is contained in prepared foods." Bottom line: unless your doctor suggests otherwise, drink to thirst. Don’t feel beholden to H20; fluids like tea, coffee and fruit juice can all keep you hydrated.
MYTH: Vitamin C can prevent a cold.
Many a drug company has made many a dollar from the widely held belief that vitamin C can prevent and cure the common cold. But is there science to back up the claim? Many studies assessing vitamin C’s cold fighting powers have been carried out over the years with mixed results. A recent review of all relevant, high-quality studies carried out by Cochrane Collaboration looked at 29 different trials where at least 200mg (milligrams) of vitamin C a day was tested against a placebo. Of the cumulative 11,306 people analyzed, regular supplementation of vitamin C had no effect on cold prevention, though it did have a modest effect in reducing the duration of symptoms. The National Institutes of Health holds a similar stance, suggesting vitamin C is “possibly effective” for treating colds, but ineffective at preventing them. Bottom line? Shelling out cash on high-dose Vitamin C supplements (it’s nearly impossible to overdose), or making a daily habit of eating citrus may help you feel better if you’re suffering, but it’s unlikely to prevent you from catching a cold.
MYTH: Eating soy causes breast cancer.
Throw out the Luna Bars, ditch the tofu, hold the edamame and save the ta-tas! Soy and its influence on breast cancer has long been a source of concern. Soy contains phytoestrogens, naturally occurring hormone-like compounds with weak estrogenic effects, which, in the lab, have shown to fuel many cancers. However, human studies haven’t found diets high in soy increase breast cancer risk. In fact, quite the opposite. A longitudinal study in The American Journal of Clinical Nutrition that followed nearly 10,000 breast cancer survivors found that women who ate the most soy had lower rates of cancer recurrence and mortality. Another study that looked at the pre-diagnosis diets of 3842 breast cancer patients across multiple ethnicities found soy intake was unrelated to mortality. The American Cancer Society’s dietary guidelines note that consumption of soy foods is not only safe but “may even lower breast cancer risk.” Bottom line? Concerns about phytoestrogens in soy and their influence on breast cancer may be unfounded.
MYTH: Oysters are an aphrodisiac.
Giacomo Casanova was said to eat 50 oysters for breakfast each morning. He also reportedly bedded half of Europe, so it’s perhaps no surprise that oysters became widely known as an aphrodisiac. But the jury’s out as to whether the claim holds scientific merit. Oysters are high in zinc—a deficiency of which has been linked to poor sperm quality—but no major study has directly linked oysters with arousal. One study presented at a meeting of the American Chemical Society in 2005 came close. Researchers found shellfish to be rich in amino acids that trigger increased levels of sex hormones, but the non peer-reviewed and unpublished study had another major flaw: it looked at Mediterranean mussels, not oysters. Some have theorized that the oyster’s sexy reputation is tied to its resemblance of female genitalia. Bottom line? A good shucking may turn you on, but there’s no proof to back up the shellfish as a sexual stimulant.
MYTH: The microwave destroys all the nutrients in vegetables.
Ask any overzealous nutrition nut, and they’ll tell you: the microwave may as well be renamed the morgue, as it zaps vegetables of their disease-fighting nutrients. Not exactly. While every cooking method can destroy some nutrients in food, the extent is determined by how long the food is cooked and how much liquid is used. Since microwave ovens can cook quickly without adding water, vegetables steamed in a microwave may keep more of their vitamins and minerals than other cooking methods, according to the Food and Drug Administration. A new study, to be published in Food Chemistry in April 2015, found microwaving contributed to an increased antioxidant level in both cauliflower and broccoli. Another study in the journal BioMed Research found microwaved cauliflower retained 98 percent of the disease-fighting carotenoids found in the raw cruciferous veg, and 64 percent more than when boiled. Bottom line? If you’re going to cook your veggies, steaming in the microwave may be one of your best options.