The Health Information You Need to Know
When conflicting medical reports surface, it's tough to know whether to switch tacks or stay the course
The Real Scoop
Anyone who's been keeping tabs on health headlines lately is bound to be baffled: One week, popping a multivitamin is good and eating soy is bad; the next week, it's the reverse. . .whaa?
The fact is, contradictory research is the norm in the science world. But when new findings refute an established, firmly held belief—as many have recently—it can be especially confusing. But don't fret: WH has uncovered the real scoop behind several current head-scratchers.
Old Thought: Flossing may help your ticker.
For decades, doctors touted the link between periodontal disease and heart disease. They thought the bacteria that collects between the teeth and causes gum disease could also enter the bloodstream, where it could trigger an inflammatory response in blood vessels and increase your risk for heart disease and stroke.
New Thinking: What happens in your mouth stays in your mouth. There's no solid evidence to support the idea that poor oral hygiene causes heart disease or stroke, an American Heart Association committee concluded after reviewing 500journal articles and studies. The report, published in Circulation, points out that factors such as smoking and diabetes can contribute to both gum and heart diseases. But that doesn't mean one condition causes the other.
Your Move: Floss on! Just not for your heart's sake. Flossing reduces your risk for gum disease (which can be painful and lead to tooth loss) and prevents foul breath, so you should still do the deed once a day, says Sally Cram, D.D.S., a Washington, D.C., periodontist.
Old Thought: Soy is a no-no if you (or a family member) have had breast cancer.
Because soy contains isoflavones, plant compounds that mimic estrogen, doctors had long been concerned that eating tofu and edamame could promote cancer development since many breast tumors are fueled by estrogen. Research has even suggested a direct link; a 2006 study found genistein, a component in soybeans, stimulated the growth of breast tumors in mice.
New Thinking: Soy foods can be safe for all women. And not only safe but also protective: A 2012 study of almost 10,000 breast-cancer survivors in the United States and China found that women who consumed more than 10 milligrams of soy isoflavones a day (the equivalent of about half a glass of soy milk) had a significantly reduced risk for breast-cancer recurrence. Soy contains antioxidants and vitamins that can benefit all women, even breast-cancer survivors. (However, these findings don't apply to all supplements; some can contain higher amounts of isoflavones.) More good news: A 2011 study in The American Journal of Clinical Nutritio reported that soy intake was associated with lower lung-cancer risk.
Your Move: Enjoy a serving a day, but don't go overboard. Soy is like chocolate and wine—it's good in moderation. "At up to 25 milligrams per day, isoflavones have protective properties," says Edward Bauman, Ph.D., coauthor of The Whole-Food Guide for Breast Cancer Survivors. "But a soy powder or protein that has 50 or 100 milligrams of isoflavones becomes problematic because the molecular structure of the food has been interfered with." Which is why Bauman recommends sticking with one serving of whole soy (edamame, tempeh) or minimally processed soy (milk, tofu) a day and avoiding highly processed versions (soy chips, soy powders, fake-meat products), which contain concentrated levels.
Old Thought: Fat-free salad dressing is the best choice.
There has never been a shortage of studies linking dietary fat with obesity, generating a constant stream of "you are what you eat" headlines. So if you're trying to slim down—or just stay at your current dress size—pouring a non-or low-fat dressing over your vegetables seems like a no-brainer.
New Thinking: Adding fat to veggies makes each bite more nutritious. Salads are bursting with important vitamins and minerals, but if you stick with fat-free dressing (or bypass dressing entirely), you're shortchanging yourself. A recent study reported that fat enhances the absorption of compounds in veggies called carotenoids, which not only produce the vivid hues found in tomatoes, carrots, and bell peppers but may also reduce the risk for cancer, cardiovascular disease, and macular degeneration (vision loss). Researchers found that dressings containing monounsaturated fats maximized absorption (compared with saturated fats), which is good news if you're watching what you eat.
Your Move: Fatten up your salad. This isn't permission to drench your greens in creamy Italian or blue cheese dressing. Instead, drizzle on canola- or olive-oil-based dressings to optimize your veggies' nutritional punch without adding to your waistline. "A full-fat dressing will probably taste better too, and that will help your salad be more satisfying," says Elisa Zied, R.D., author of Nutrition at Your Fingertips.
Old Thought: Popping a daily multivitamin is a smart habit.
Your body requires 13 different vitamins to operate optimally, and it's hard to be sure you're getting all those in your diet (especially on days when you skip breakfast or grab bar nachos for dinner). Taking a pill has always seemed like a good way to fill in the gaps, and why bother with separate supplements when one multi covers it all?
New Thinking: Multis may not always help. Researchers say it's possibly another case of too much of a good thing: A study published in the Archives of Internal Medicine reported that women who took multivitamins daily over 18 years had a 2.4 percent increased risk for death. "Basically, every compound can be toxic if the dose is high enough," says study author Jaakko Mursu, Ph.D., of the University of Eastern Finland. However, he says, the higher mortality risk might be due to disease and not supplement use, as some study participants may have begun using supplements after receiving a diagnosis of disease.
Your Move: Focus on getting vitamins from food. It is possible to get sufficient nutrients from your diet. If you generally consume veggies, fruits, lean proteins, whole grains, and low-fat dairy foods and usually avoid baddies like saturated fats, trans fats, and added sugars, you should be in good nutritional shape. But if you know you won't be eating great one day, or if you are cutting calories in an attempt to lose weight (and perhaps by doing so, may be consuming fewer nutrients), taking a multivitamin might be a good idea, says Zied. People with doctor-detected deficiencies, like low iron or vitamin D (many people are lacking this "sunshine vitamin," so have your level checked) are best off taking individual supplements to increase those specific nutrients. Of course, if you're pregnant or hoping to be, go ahead and pop a pill: A prenatal multi gives a future mama's body the folic acid, calcium, and iron it needs.
Old Thought: Yoga is gentle on the body.
Study after study has sung the praises of hitting the mat. The ancient practice is credited with tons of better-body perks—from improved strength and flexibility to reduced anxiety and blood pressure. And because you get all this minus any jarring jumping, yoga studios have established themselves as do-no-harm safe havens, especially for injury-prone folks.
New Thinking: Yoga can hurt you. William J. Broad, a lifetime yoga devotee, made headlines earlier this year when he released his book The Science of Yoga, which investigates the rewards and the risks of the practice, challenging its wholesome reputation. His book highlights a survey of more than 1,000 yoga teachers, therapists, and doctors who reported that lower-back and shoulder injuries were fairly common complaints among students and patients. And although rare, herniated spinal disks, fractures, and even heart problems occurred as a result of mat sessions. The cause? The majority of respondents pointed to inadequate teacher training.
Your Move: Do yoga—mindfully. Just as you wouldn't tackle a marathon on your first day as a runner, you shouldn't try to tie yourself into a pretzel your first time on the mat. Cathy Lilly, a senior yoga teacher in New York City, recommends that beginners focus on classical yoga, mastering the fundamental Hatha poses before moving on to more advanced forms like Vinyasa Flow and Astanga. "Get the key pieces in place first," she says. Injuries can strike when transitioning from one pose to the next, so periodically pause, breathe, and feel how you're planted on the ground, instead of rushing through poses. Welcome use of accessories such as blocks, straps, and blankets to help avoid straining, and always let your instructor know if you have any injuries or tight or tender spots so she can recommend modifications.