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What Are Functional Foods?

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You may have heard of "functional foods" -- bread, margarine, yogurt, and even eggs that have nutrients added to help your heart.

You can get these nutrients from the foods that naturally contain them: vegetables, fruit, whole grains, fish, and healthy fats. But the typical American diet can sometimes fall short. So now they're added to some foods that don't normally have them.

Three that are added to many foods are plant stanols or sterols, fiber, and omega-3s. Here's a look at what they do for you.

Plant Stanols and Sterols

What are they? Plant stanols and sterols are found in fruits, vegetables, nuts, and seeds. Their structure is a lot like cholesterol. But they block cholesterol in your digestive system, so less cholesterol moves into your bloodstream to clog your arteries.

How much do you need? Getting 2 grams of either plant stanols or sterols daily can bring down bad cholesterol (LDL) by 5% to 15% in a few weeks. If you already eat butter, margarine, or oil-based spreads, switching to one with extra plant stanols or sterols might be a good move, says Christine Gerbstadt, MD, RD, author of Doctor's Detox Diet. It's easy to overdo fats, though, so eat these margarines and oils in moderation.

Fiber

What is it? Fiber is naturally in plant foods: fruits, vegetables, beans and other legumes, and whole grains . Food scientists have created powdered fiber with no real flavor. It's added where you'd never expect to find it: in hot dog buns, sugary cereals, even yogurt. On the label it may be called inulin, maltodextrin, polydextrose, or chicory fiber. It often comes from different sources than the dietary fiber in oats, whole wheat bread, or bran cereal.

How does fiber help the heart? It's well-known that fiber can bring down your cholesterol level. Eating enough fiber can also lower your chances of developing heart disease, type 2 diabetes, and obesity. The problem is that most people don't get enough.

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"Fiber added to bread or cereal can be a good thing," says Susan Moores, MS, RD. But scientists don't know whether adding refined fiber to foods will give you the same health benefits as eating fiber naturally found in foods. The best bet is to follow a healthy diet that includes foods that are naturally high in fiber: beans, vegetables, and whole grains, Moores says.

How much fiber do you need? Women need about 25 grams of fiber daily, while men need about 38 grams a day. Your body needs two kinds of fiber. Soluble fiber, which slows digestion, can be found in beans, nuts, and grains including oats. Insoluble fiber, which helps food pass through the body, and can be found in vegetables and whole grains.

Omega-3s

What are they? Omega-3s are a "good" kind of fat found in fish like salmon, tuna, cod, sardines, anchovies, herring, and trout. They're also found, in lower amounts, in nuts and seeds like walnuts, almonds, and flax.

How do they help your heart? Eating enough omega-3s helps protect your arteries from the sticky plaque that can cause a heart attack or stroke. Omega-3s also protect against a dangerous abnormal heartbeat, and they can lower unhealthy blood fats called triglycerides.

The best heart benefits, though, come from two kinds of omega-3s found mostly in fish: DHA and EPA. Plant foods have a different type of omega-3 called ALA.

Most foods you see in the store with added omega-3s -- cereal, pasta, soy milk, yogurt, margarine, and eggs -- use ALA, which may not help your heart as much as the kind found in fish. Also, many of these foods don't have enough omega-3s, Gerbstadt says.

How much omega-3 do you need? The American Heart Association advises people to eat fish at least twice a week to get enough omega-3s. A 4-ounce serving of salmon has 2 grams of omega-3s. If you have a heart condition, ask your doctor if you need higher amounts of omega-3s.

Remember, most of the nutrients you need should come from whole grains, fruits and vegetables, low-fat dairy, fish, and lean meat. No one knows whether fortified foods can provide all the health benefits you get from the complex mix of nutrients in whole foods. Your doctor or a dietitian can let you know what would be best for you.

WebMD Feature Reviewed by Laura J. Martin, MD on December 24, 2012

Sources

SOURCES:

Elaine Magee, RD, MPH, nutritionist, R&DE Stanford Dining, Stanford University; author, Food Synergy, Rodale Books, 2008; author, Tell Me What To Eat If I Suffer From Heart Disease, New Page Books, 2010.

Christine Gerbstadt, MD, MPH, RD, author, Doctor's Detox Diet, Nutronics, 2012.

Kerry Neville, MS, RD.

Susan Moores, MS, RD, nutritionist, St. Paul, MN.

Tufts University School of Medicine: "Omega-3 Fatty Acids."

University of Delaware, Cooperative Extension: "Calcium."

American Heart Association: "Calcium, Dietary," "Fish and Omega-3 Fatty Acids."

University of Maryland Medical Center: "Vitamin D."

National Institutes of Health: "Dietary Supplement Fact Sheet: Vitamin D," "Your Guide to Lowering Your Cholesterol With TLC."

Joslin Diabetes Center: "Lower Your Cholesterol with Plant Sterols and Stanols."

U.S. Department of Agriculture: "Dietary Guidelines for Americans 2010," "Why Is It Important to Eat Grains, Especially Whole Grains?"

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