Biggest Nutrition and Food Myths Busted
1. “Eggs are bad for your heart.”
Eggs do contain a substantial amount of cholesterol in their yolks-about 211 milligrams (mg) per large egg. And yes, cholesterol is the fatty stuff in our blood that contributes to clogged arteries and heart attacks. But labeling eggs as “bad for your heart” is connecting the wrong dots, experts say. “Epidemiologic studies show that most healthy people can eat an egg a day without problems,” says Penny Kris-Etherton, Ph.D., R.D., distinguished professor of nutrition at Penn State University.
How? For most of us the cholesterol we eat-in eggs or any other food-doesn’t have a huge impact on raising our blood cholesterol; the body simply compensates by manufacturing less cholesterol itself. The chief heart-disease culprits are “saturated and trans fats, which have much greater impact on raising blood cholesterol,” notes Kris-Etherton. Seen through that lens, eggs look more benign: a large egg contains 2 grams of saturated fat (10 percent of the Daily Value) and no trans fats.
But before you celebrate with a three-egg omelet, consider the American Heart Association’s diet and lifestyle recommendations, which Kris-Etherton helped write: Limit your cholesterol intake to less than 300 mg daily-less than 200 mg if you have a history of heart problems or diabetes or are over 55 (women) or 45 (men). “If you do the math, that works out to less than an egg a day for this population-more like two eggs over the course of the week,” she notes. “Eggs can fit in, as long as you make room for them in the rest of what you’re eating.
2. “High-Fructose Corn Syrup (HFCS) is worse for you than sugar.”
Though consumers who fill their shopping carts with products labeled “No HFCS” might feel otherwise, the idea that high-fructose corn syrup is any more harmful to your health than sugar is “one of those urban myths that sounds right but is basically wrong,” according to the Center for Science in the Public Interest, a Washington, D.C.-based nutrition and health advocacy group.
High-fructose corn syrup was created to mimic sucrose (table sugar), so its composition is almost identical to sucrose’s (55 percent fructose, 45 percent glucose; with sucrose the ratio is 50:50). Calorie-wise, it’s a dead ringer for sucrose. And in studies that compare the effects of HFCS with other sweeteners, HFCS and sucrose have very similar effects on blood levels of insulin, glucose, triglycerides and satiety hormones. In short, it seems to be no worse-but also no better-than sucrose, or table sugar.
“The debate about HFCS and sucrose [table sugar] is taking the focus off the more important question,” says Kimber Stanhope, Ph.D., R.D., a researcher at the University of California, Davis, who has studied the sweetener extensively. “What we should be asking is ‘What are the effects of all sugars (HFCS and sucrose) in the diet?'”
Epidemiologic studies show that consuming large amounts of added sweeteners-primarily in sodas and other sweetened drinks-is associated with greater risk of fatty liver disease, insulin resistance, heart disease and type 2 diabetes. And it’s not just the extra calories they provide that may be hurting us; research by Stanhope and others suggests that fructose itself in added sugars may be hazardous to our health too. One problem is that our bodies weren’t designed to handle a large amount of fructose at a time, she notes, because we wouldn’t have come across it in our food supply. “If you look at what nature provided for humans to eat, we only had fructose in whole fruit, in amounts that are relatively dilute.” Problems arose when we learned how to turn foods-which contain fiber, water and other nutrients-into pure sources of sugars (e.g., refining sugarcane into table sugar).
But the associations between sweetener consumption and disease don’t implicate just HFCS, which despite its name contains only a little more fructose than sucrose does, Stanhope emphasizes. It’s the sheer amount of the sweet stuff we consume that matters or, to put it another way, it’s the dose that is the problem. Too much honey, agave syrup or dehydrated cane juice would likely cause the same health problems.
“The American Heart Association recently recommended that women consume no more than 100 calories a day in added sugars [6 teaspoons]; men, 150 calories [9 teaspoons],” Stanhope notes. Our current intake, however, hovers around 355 calories per day. “The U.S. population isn’t anywhere close to [the AHA’s] goal.”
3. “Carbohydrates make you fat.”
Contrary to the theories of the low-carb/no carb manifesto, Dr. Atkins’ Diet Revolution, first published in 1972 (and the similar books that followed), there’s nothing inherently fattening about carbohydrates, says Jean Harvey-Berino, Ph.D., R.D., chair of the department of nutrition and food sciences at the University of Vermont and co-author of The EatingWell Diet (Countryman, 2007). “It’s eating too many calories, period, that makes you fat.”
There’s no question that loading up on sugary and refined-carbohydrate-rich foods, such as white bread, pasta and doughnuts, can raise your risk of developing health problems like heart disease and diabetes. But if you cut out so-called “good-carb” foods, such as whole grains, beans, fruits and vegetables, you’re missing out on your body’s main source of fuel as well as vital nutrients and fiber. What’s more, for many people, a low-carb diet may be harder to stick with in the long run.
When a handful of major studies recently compared low-carb diets with low-fat diets and other approaches to losing weight, notes Harvey-Berino, they found that in the first few months, those following the low-carb diets tended to lose slightly more weight. “That’s because low-carb diets are more restrictive,” she explains. “Anything that limits your choices will help you lose weight initially.” But after a year or as much as three years, weight-loss differences between the diets tend to even out. One recent report noted that although there was a greater weight loss initially, low-carb dieters tended to regain more weight by the end of three years when compared with low-fat dieters.
But Harvey-Berino acknowledges that low-carb eating can help many people manage their weight-especially if you’re “one of those people who has a hard time staying in control when you eat carbohydrate-rich foods.” No matter how you slice it, the best diet is one you can stick to, she adds. “If you can stick with an Atkins-like regimen, then go for it.”
4. “A raw-food diet provides enzymes that are essential to healthy digestion.”
“Raw foods are unprocessed so nothing’s taken away; you don’t get the nutrient losses that come with cooking,” says Brenda Davis, R.D., co-author of Becoming Raw: The Essential Guide to Raw Vegan Diets (Book Publishing, 2010). But the claim by some raw-food advocates that eating raw boosts digestion by preserving “vital” plant enzymes, Davis explains, just doesn’t hold water. “Those enzymes are made for the survival of plants; for human health, they are not essential.”
It’s true that heating a food above 118°F inactivates plant enzymes, “since enzymes are proteins and proteins denature [break down] with heat,” explains Andrea Giancoli, R.D., a Los Angeles-based spokesperson for the American Dietetic Association. “But those enzymes are denatured-and thus inactivated-when they reach our stomachs. Our stomach acids are designed to break down proteins very efficiently.” If associated with living microorganisms (such as those in fermented foods like sauerkraut), plant enzymes might reach the small intestine intact, adds Davis, “but their overall contribution to human digestion appears minimal.”
What about the claim by some raw-foodistas that our bodies have a limited lifetime supply of enzymes-and that by eating more foods with their enzymes intact, we’ll be able to spare our bodies from using up their supply? “The reality is that you don’t really have a finite number of enzymes; you’ll continue to make enzymes as long as you live,” says Davis. Enzymes are so vital to life, she adds, “the human body is actually quite efficient at producing them.”
5. “Your body can’t use the protein from beans unless you eat them with rice.”
Proteins-which our bodies need to make everything from new muscle to hormones-are made up of different combinations of 20 amino acids. Thing is, our bodies can make only 11 of these amino acids; we must get the other nine from food. Animal-based protein-rich foods like eggs and meat provide all nine of these “essential” amino acids, but nearly all plant foods are low in at least one. Experts used to say that to get what your body needs to make proteins, you needed to pair plant-based foods with complementary sets of amino acids-like rice and beans. Now they know that you don’t have to eat those foods at the same meal. “If you get a variety of foods throughout the day, they all go into the ‘basket’ of amino acids that are available for the body to use,” says Winston J. Craig, Ph.D., R.D., nutrition department chair at Andrews University in Berrien Springs, Michigan.