How Much DHA and Iron You Really Need
Your energy bar is bolstered with iron, your sports drink is spiked with calcium, your bread has added fiber, and your oatmeal has all of the above. Before you give yourself props for your diet, consider this: If you also pop a daily multi, you could be OD'ing on certain nutrients. In some cases, food fortification makes sense; for example, if you're lactose intolerant, OJ with calcium and vitamin D is a lifesaver for your bones. Other times "it's just an attempt to make a poor nutritional choice look like a good one," says Jeffrey Blumberg, PhD, a professor at the Friedman School of Nutrition Science and Policy at Tufts University in Boston. There's little FDA regulation of so-called functional foods unless they bear a health claim. As long as a product packs more than 20 percent of your daily dose of a vitamin or mineral, the label can call it an "excellent source" of that nutrient — whether you need it or not. Plus, companies are required to list nutrition facts only for substances with FDA daily values, such as fiber. That leaves you in the dark on others, including omega-3s and folic acid. Here, get the facts about seven common ingredients that are popping up in foods and decide whether they deserve a spot in your shopping cart.
Docosahexaenoic acid is one of the omega-3s in fatty fish. The other is EPA, or eicosapentaenoic acid. DHA helps cells communicate with one another and your nervous system, while EPA fights inflammation and keeps your heart healthy. "If you're eating only foods with DHA, you're not reaping all the benefits you'd get from fish or even a fish-oil supplement, which contain both types," says Evelyn Tribole, RD, author of The Ultimate Omega-3 Diet. DHA-fortified foods, which include cheese, eggs, milk, peanut butter, and tortillas, also aren't significant sources. Two tablespoons of enriched peanut butter provides 32 milligrams of omega-3 fatty acids — small potatoes compared with the more than 1,000 milligrams in a three-ounce salmon fillet. You would have to eat more than 62 tablespoons to get the amount that's in one serving of fish.
Bottom line: Don't rely on pricey DHA-fortified foods. Instead, spend your money at the fish counter, on salmon, oysters, and trout. If you're not a seafood fan, take a fish-oil supplement that provides at least 220 milligrams each of EPA and DHA.
Listen up, meat eaters: It's not just vegetarians who suffer from iron deficiency, which can cause headaches, sap your endurance, and leave you exhausted. Sure, you get some iron from red meat, but a three-ounce serving of beef supplies only about 13 percent of your daily dose. Two other key sources, chicken liver and oysters, aren't dietary staples for most of us. Plus, your body can't use all the iron in many foods. Beans, for example, contain a compound called phytic acid that reduces absorption by as much as 50 percent.
Bottom line: One in five women falls short of the recommended 18 milligrams daily. So go for a variety of iron-enriched foods: A cup of rice, a cup of spaghetti, a pita pocket, and a veggie burger gives you 46 percent of your day's quota.
How Much Fiber and Folic Acid You Need
Some 20 years ago women were coming up short on folate. This B vitamin, found in avocados, leafy greens, orange juice, and peanuts, is a must if you're pregnant; it protects against neural tube defects and aids normal cell development. So food companies started putting a synthetic version, called folic acid, in bread, pasta, and rice. These days many of us get the recommended 400 micrograms daily, but there's a catch: Manufacturers, taking a more-is-better approach, add folic acid to foods like cereal and energy bars. While emerging research shows that it's okay to get a lot of folate from whole foods, too much folic acid may be dangerous because it may interfere with DNA synthesis or even cause nerve damage. One study has linked it to an increased cancer risk.
Bottom line: Experts don't know how much folic acid you can consume safely, so beware of supplements and enriched foods that claim to provide a big chunk of your daily intake. Companies aren't always required to post on labels the amount of folic acid products contain, but they like to brag. "Look at the box. If an enriched food has more than 20 percent of the daily value, skip it," says Hope Barkoukis, PhD, RD, associate professor of nutrition at Case Western Reserve University in Cleveland.
Most of us consume only about half the daily recommendation for fiber, which keeps you full, aids digestion, and helps lower cholesterol. This material is found naturally in such foods as whole grains, beans, fruits, and vegetables, and manufacturers have added a slew of fiber, including inulin, polydextrose, and resistant maltodextrin, to unexpected products, including ice cream and yogurt.
Bottom line: If you're eating a lot of produce and whole grains and still need help reaching the recommended 25 daily grams, fortified foods are okay. Just don't start adding them willy-nilly to your diet; suddenly boosting your fiber intake can cause bloating. Increase gradually to give your system time to adjust, and check for fiber on all food labels — even unlikely sources, like ice cream.
Get Enough Vitamins A, C, and E
There are two forms of this vitamin but only one that you need to worry about. Provitamin A carotenoids are in good-for-you foods like cantaloupe, carrots, spinach, and other produce. For most women, it's almost impossible to get too much, because the body uses only what it needs. Retinol is the other kind of vitamin A; it's found naturally in meat and dairy, and manufacturers add it to waffles, snack bars, low-fat yogurts, and more. You need retinol to fight infection and keep your skin and eyes healthy, but if you consume way too much, it can weaken your bones and increase the risk of birth defects if you're pregnant.
Bottom line: Keep an eye on nutrition-facts labels so you don't get more than 100 percent of your vitamin A daily, especially if you take a multivitamin. Just two whole-grain waffles with margarine, a snack bar, and a container of low-fat yogurt supplies more than 75 percent of the 2,310 international units (IU) that you need every day.
Vitamin C guards against infection, keeps your skin smooth and firm, and may even help you slim down. A recent study found that lower levels of C translates to a higher body mass. This may be because your body needs the vitamin to produce carnitine, a compound that helps turn fat into fuel. The good news is that this vitamin is easy to obtain from foods like oranges, strawberries, and bell peppers. Unfortunately, many of us skimp on produce, so about 15 percent of adults in the United States are vitamin C deficient. Make sure to get the recommended 75 milligrams a day.
Bottom line: It's best to get C from fruits and vegetables (your daily max is 2,000 milligrams). Watch out for foods fortified with the vitamin, including nutritionally enhanced waters and fruit-flavored drinks, which are loaded with empty calories.
If you watch what you eat, you may be skimping on E, because many natural sources — high-fat nuts, seeds, and oils — scare off dieters. But vitamin E is an antioxidant that helps keep your heart and immune system kicking. The recommended daily dosage you'll see on food labels is 30 :IU, and many foods with added E — cereal, energy bars, and snack bars — deliver between 20 and 100 percent of that.
Bottom line: Dig in. "Almost no one gets 100 percent of her daily value of vitamin E from her diet," Blumberg says. Foods fortified with the nutrient supply a substantial portion of your recommended daily intake without putting you at risk of exceeding the max, which is 1,500 IU.
Nutrients You Need the Most
Practically all women, especially those who work out regularly, can use more of this trifecta of frequently overlooked nutrients.
What it does: In addition to helping you use energy and build protein, it fosters strong bones and keeps blood sugar and blood pressure on an even keel.
Super sources: Too much from supplements can cause stomach problems, so get magnesium from fish, nuts, beans, leafy greens, and whole grains.
What it does: This mineral boosts bone health and helps ward off PMS, prevent high blood pressure, and keep your heart and muscles pumping.
Super sources: If you're not getting three servings of dairy (or the fortified equivalent) a day, take a supplement. Aim for 1,000 milligrams daily, split into two doses for better absorption.
Nutrient: Vitamin D
What it does: In addition to helping your body use calcium, D may also help prevent breast and colon cancer and protect against diabetes.
Super sources: It's found naturally in a few foods, including fatty fish. The recommendation is 200 IU, but many experts advise as much as 2,000 IU daily from fortified milk, OJ, yogurt, cereal, D3 supplements, and sunlight.
Originally published in FITNESS magazine, November/December 2010.
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