Next to sex and celebrities, health and nutrition may be the favorite topic of todays mass media-from TV to magazines and newspapers to the Internet. But the popularity of eat this, dont eat that advice doesnt mean the information youre getting is always accurate. In thousands of pages and programming hours, its easy to let a story run away from the science.So weve been collecting examples of iffy and incomplete advice from media outlets ranging from Oprah to Bon Apptit, to do a reality check. Here are some of the facts you might have heard or read recently-and what the science really says:Yogurt helps your body fight the flu (USA Weekend): Varieties of yogurt touting live cultures and probiotics may improve digestive health. But theres little evidence that the healthful bacteria in yogurt can protect you from the virus that causes influenza, help your body fight the flu or boost your immune system. For that matter, the power of any individual food or vitamin to significantly im-prove immune-system function remains largely unproven. The same article touted purported flu-fighting benefits of beta-carotene, garlic and lemons; none has been definitively shown in well-designed human studies to prevent the flu or improve immune function. (For more on nutrition and the flu, see our January 2010 Special)Butter is better for you because it has fewer calories Bon Apptit): True, a tablespoon of butter contains only 100 calories, compared to 120 in a tablespoon of liquid vegetable oil. Thats because butter contains about 20% water. Once the water boils off in cooking, the remaining butter fat contains the same amount of calories as an equivalent portion of vegetable oil. Because butter contains 7.3 grams of saturated fat per tablespoon, liq-uid vegetable oil-lower in saturated fat, higher in healthy polyunsaturated fat (see page 8)-is always a smarter choice. Flaxseed, walnuts and hemp are good sources of omega-3s (Dr. Oz): All these plant foods are indeed good sources of alpha-linolenic acid (ALA), an omega-3 fatty acid, and nuts in par-ticular have other heart-health benefits. But its a mistake to lump all omega-3s together: ALA has different health ef-fects than the omega-3s found in fish, EPA and DHA. Its true that your body converts ALA into these more complex omega-3s, but that conversion is very inefficient. One recent review found that the body converts only between 8% and 20% of ALA into EPA, and just 0.5% to 9% into DHA. In testing of flaxseed supplements, while levels of EPA in the body rose, there was no increase at all in D.Raw vegetables are always more nutritious (Today Show): Raw is often the best way to go when serv-ing veggies, but not always. While wa-ter-soluble nutrients such as vitamin C, the B vitamins and some antioxidants get lost in cooking, others actually need the heat to bring out their healthy best. The most prominent example is the lycopene in tomatoes, which gets released by cooking; testing has shown this also applies to other compounds in the carotenoid family. Cooking vegeta-bles can also improve their digestibil-ity-and hence the availability of their nutrients to the body. Cooking helps break down vegetable proteins, and loosens or removes the protective coat-ings that might keep them from being fully digested. (For more on how cook-ing affects nutrition, see our December 2008 Special Report.)Iodine supplements and soy milk are good for underactive thyroid (Oprah): These days, iodine defi-ciency is relatively rare. The notion that too little iodine causes hypothyroid-ism is a myth, according to David Cooper, MD, a professor of endocrinol-ogy at Johns Hopkins University who specializes in thyroid disease. In fact, extra iodine exacerbates mild hypothy-roidism. And if youre taking medica-tion for underactive thyroid, soy milk can block your bodys ability to absorb the drug if you drink it within several hours of taking the medication.Coconut oil helps you lose weight and get a flat belly (Health): This article cited a Brazilian study comparing weight loss in women who took a 30-milliliter supplement of coconut oil to a control group taking soybean oil. All the women also dieted and exercised, which no doubt con-tributed more to their weight loss than the coconut oil. The US governments exhaustive PubMed database of medi-cal research shows no human studies and only one study in mice demonstrat-ing weight-loss benefits for coconut oil. Since coconut oil is high in calories and saturated fat (11.7 milligrams per tablespoon), which contributes to heart disease, we wouldnt recommend it for weight loss or belly-flattening without a lot more evidencInstead of salmon, eat algae (Dr. Oz): Worried about mercury? An Insti-tute of Medicine expert panel says the benefits of eating fish outweigh the risks, and in any case salmon is not among the fish most susceptible to mercury. Concerned about sustainabil-ity? The Environmental Defense Fund rates wild Alaskan salmon and canned salmon among the eco-best choices. Algae, suggested as an alternative to salmon, can also contain toxins from the oceans where they grow, and some algae supplement products have been found to contain potentially harmful impurities and additives. Besides, youre unlikely to make dinner from a plateful of algae; one of the many advantages of eating more fish is that it takes the place of less-healthy protein sources in your die
