Health Encyclopedia

Functional Foods—Hype or Health Benefit?

Can you prevent heart disease by eating fish, prevent cancer with tomato sauce, or keep your memory sharp with gingko biloba?

Many Americans would answer yes. According to the Nutrition Business Journal, they're betting that these "functional" foods—also called herbs, supplements, nutraceuticals, or phytochemicals—can do all this and more. Whether they get what they pay for—or more than they bargained for—is an issue that concerns some experts.

Consumers are flooded with functional food claims, some supported by research and many unproven. The FDA regulates certain functional foods. Yet, due to the vast number of products and legal loopholes, this regulatory oversight and control is somewhat limited. As a result, companies often use creative marketing—perhaps fraudulent or unproven—to sell these products. In the end, the consumer is left to decipher whether the touted health benefits are true, ultimately causing confusion.

The International Food Information Council defines functional foods as those that have biologically active components that provide health benefits beyond basic nutrition, such as promoting health, or preventing or curing disease. These include foods in which the beneficial substances occur naturally; for example, fruits and vegetables naturally contain antioxidants. They also include foods in which active substances are added as supplements; for example, orange juice is often fortified with calcium. Nutraceuticals are bioactive compounds extracted and concentrated from foods and formulated into supplements. For example, fish oil supplements contain the fatty acids extracted from fish.

Better—or not?

As Americans have taken more responsibility for their health, they've created a demand for these reportedly beneficial foods and supplements, and the marketplace has been eager to respond.

As a result, shelves in grocery and health-food stores bulge with hundreds of products that manufacturers claim to be beneficial. But consumer safeguards haven't kept up with this boom in products.

Only a small percentage of active chemicals in plants have been thoroughly tested for their potential roles in preventing disease and promoting health. Federal regulations keep a tight rein on health claims made on food labels, but the rules aren't perfect, and they're not always enforced correctly. So many substances marketed as dietary supplements have unproven or doubtful benefits. Even more concerning is the fact that some of these foods may contain dangerous additives.

These are some of the potential problems:

  • Possible interactions with physical conditions or medications. Kava, for example, is an herb that's supposed to promote relaxation, but it has been linked to serious liver damage, including hepatitis, cirrhosis and liver failure, according to the FDA. Anyone who has liver problems or takes medication that can affect the liver should check with his or her doctor before taking kava.

  • Overdoses. You may not know how much of a substance you're getting from any given product, or how much of it you actually need. Even if an additive is known to be useful, such as folic acid, you may consume more than you need if you use more than one product that contains it.

  • Purity. Herbal supplements are largely unregulated, so you may not know their purity and strength. Several studies have shown that the listed ingredients are often not actually in the product or that certain ingredients have been substituted with others that may or may not be active. One recent study, for example, showed that several samples of black cohosh contained Asian cohosh but no black cohosh.

  • Side effects. Without accurate strength or dosing information, the effect of an additive may surprise you. Just like prescription drugs, "natural" additives and supplements can still cause allergic reactions, other unwanted side effects, and interact negatively with other medications. 

  • Adulteration. Substances may be added to the supplement or nutraceutical that are illegal, poisonous, or should be taken by prescription only. A hospital in Toronto, for example, found that sildenafil (Viagra) was present in two of seven nonprescription herbal erection pill medications. Because sildenafil does not occur naturally, the remedies were clearly adulterated. Some herbal medications from China, South America, and Mexico have been found to contain high levels of mercury and lead.

Balance is best

For most people, the best advice is to eat a well-balanced, low-fat diet filled with fruits, vegetables, and whole grains. To consume more disease-fighting antioxidants, choose colorful foods—like bright red tomatoes and dark green vegetables.

Here's what to do before you try foods and supplements touted to promote health:

  • Read the label. Read the label and try to identify each ingredient. If in doubt, check with the Office of Dietary Supplements at the National Institutes of Health for additional information.

  • Check the research. Find out what has been reported about the active ingredient in peer-reviewed medical literature.

  • Look at your diet. How does the food fit into your own healthy-eating plan?

If you eat a healthy diet, you may not need an expensive "designer" food. Spend your money on high-quality fruits and vegetables. The nutritional pay-off will outperform most functional foods. If you do decide to try an herbal or dietary supplement, be sure to discuss it with your doctor first since these products can cause unwanted side effects and interfere with other medications.  

Medical Reviewers:

  • Averett, Jennifer, RD