Functional Beverages

The space shuttle's external fuel tank falling to Earth after separation from Endeavour following launch on Wednesday, July 15, 2009. Shuttle program manager John Shannon said the thin layer of foam insulation on the central area of the tank peeled away in approximately 6-inch strips (see in detail on right). AP Photo/NASA
Functional beverages (also known as "neutraceuticals") are beverages fortified with dietary supplements and herbal medicines. And they are becoming a multi-billion dollar industry.

But consumers should think twice before sipping drinks that promise to "enlighten your senses" or "sharpen your mind." In many cases, the supplements in these beverages have very little science behind them. Dr. Mallika Marshall from CBS affiliate WBZ-TV in Boston has the details.

In fact, the Food and Drug Administration has never approved many of the herbs and other substances in the new products as allowable additives. And while the agency has never determined that they are safe to eat, it has not sought to ban them, either, so food companies have the right to add them to their products.

Unlike the many herbal medicines that contain the same ingredients, the new drinks rarely carry recommended doses on their labels. Even labels that note how much of a particular herb is inside often remain quiet about the concentration of the extract.

Some in the science community say that the companies that manufacture the beverages have been adding herbs in such low doses that they probably pose no risk at all. But that also means the herbals may be of little benefit.

The following are some of the most popular herbs found in these drinks:

Kava: Kava is said to relieve anxiety. It has made news recently because there have been suspected cases of liver toxicity caused by it. It has been banned in Switzerland, and France and other European countries are considering banning it. England has asked stores to voluntarily pull it from the shelves.

St. John's Wort: For years, St. John's Wort has been touted as a way to relieve moderate to major depression. But a recent study found that it has little to no effect on major depression. Also, recent research has found that St. John's Wort reduces the effectiveness of some drugs by speeding up the metabolism of the liver. For instance, if used in combination with a chemotherapy drug, St. John's Wort reduced its effectiveness by helping the body process it quicker.

Ginkgo Biloba: It may increase circulation and is used to enhance memory and alleviate the effects of dementia. But it also acts as a blood thinner and can exacerbate bleeding in people taking other anticoagulants, including aspirin.

Ginseng: Ginseng may enhance stamina and endurance. Many people take it before exercise. It is considered pretty harmless, but may adversely affect blood sugar levels.

Echinacea: Many people take it if they feel like they have a cold coming on, because they believe it may enhance the immune system. But it is related to ragweed so some users may have an allergic reaction.