SUNDAY, April 1, 2007 (HealthDay News) -- The line between the supermarket and drug store keeps getting fuzzier.
Television commercials for Danone's "Activia" line of yogurts claim it's just the thing for folks struggling with what gastroenterologists call "slow transit time."
Switch the channel, and ads for sterol-enriched Becel margarine trumpet its cholesterol-lowering goodness.
Then there are the new "fitness waters," loaded with antioxidant vitamins.
Each of these products cost more than "regular" yogurts, margarines and bottled waters. But are they worth it?
"It's a personal choice," said Patricia Vasconcellos, a Boston dietitian, diabetes expert and spokeswoman for the American Dietetic Association. She said that most of these "functional food" products do deliver on their promises -- but that doesn't mean everyone needs them, or stands to benefit equally.
Take the example of the margarines, cooking oils, milk drinks and other members of the Becel line of cholesterol-lowering foods. Fortified with plant sterols and stenols, they hit supermarket shelves in the late 1990s and can cost twice as much as regular butter or margarine.
"In studies, sterols and stenols have been proven to lower your total cholesterol and your LDL 'bad' cholesterol,'" Vasconcellos said. In fact, according to information on the Becel Web site, clinical-trial participants who took in 2 grams of sterols per day from these products saw a 10 percent to 15 percent drop in LDL within "a few weeks."
Vasconcellos said the spreads "can be expensive. But if you just use it for toast or a potato, instead of cooking with it, that's much cheaper. For cooking, I'd recommend other healthy fats, such as olive or canola oil."
She said that even people who take a cholesterol-lowering statin drug such as Lipitor, Pravachol or Zocor may still benefit from sterol-containing products. "It will only enhance the effect, and work with the statin," Vasconcellos said.
Other functional foods are populating the dairy aisle. Danone recently introduced its Activia line of flavored yogurts enhanced with their own specially developed strain of "friendly" gut bacteria, Bifidus Regularis. The bacteria's name announces the purpose of the Activia line: To encourage frequent, on-time bowel movements.
In scientific parlance, the trip that food makes between ingestion, absorption and evacuation as waste is called "intestinal transit."
"What Danone has shown in placebo-controlled studies [with Activia] is that people who have slower intestinal transits -- maybe one bowel movement every 72 hours or more -- those people can reduce that transit time down closer to 24 to 28 hours," explained one of the nation's leading experts on bacteria-enhanced "probiotic" foods, Mary Ellen Sanders.
Sanders, a former researcher in this area who now works as a consultant for a variety of industry and public clients -- including Danone -- noted that all yogurts contain bacteria, since these microorganisms are essential to turn milk into yogurt.
"In fact, many yogurts will have 'contains L.acidophilus' or something like that on the label, because they know there's a niche market of consumers looking for that," said Sanders, past president of the International Scientific Association for Probiotics and Prebiotics, who is based in Centennial, Colo.
However, most regular yogurts either don't contain the right strains of bacteria, or contain levels that are so low they have no real effect on human digestive physiology, Sanders said.
Activia is somewhat different, she said, because the company has tailored the yogurt around a specific strain of bacterium with known digestive potency and greatly boosted the amount available in each serving. "They've also documented that the strain does survive intestinal transit, meaning that it has effects all the way through your intestine," Sanders said.
However, she agreed with Vasconcellos that spending about a third more per serving on Activia compared to a regular brand of yogurt might not make sense for everyone.
"Remember, if people just ate more fiber in their diets, more fruits and vegetables, they'd probably have bowel movements more frequently, anyway," Sanders pointed out.
And she noted that bowel-movement frequency varies widely between individuals, naturally. "It's not a real disease, and if it's not bothering you, what difference does it make?"
The Activia line has been a success for Danone, however, and more probiotic foods are following in its wake, including "Vive probiotic digestive wellness cereal," from granola-cereal maker Kashi. Sanders even noted that, "a small company just introduced chocolate candy bars with probiotics."
Other functional foods are getting airplay, too. Major beverage companies are hyping their new "fitness drinks," tapping into Americans' thirst for quick, easy nutrition. Brands like Gatorade's "Propel" come with dissolved antioxidants, such as vitamins C, E and some B variants.
"They tend to have more of these types of ingredients, but less carbohydrates than usual sports drinks," said Vasconcellos. "However, if you're taking in a balanced diet -- eating a wide variety of foods, plenty of fruits and vegetables, low-fat dairy, whole grains -- and drinking enough fluids, then these types of specialty drinks really aren't necessary," she said.
There's more on healthy nutrition at the American Dietetic Association.