May 19, 2010 -- Parents who want to reduce the number of coughs, stomach aches and infections in their children may want to reach for the probiotic yogurt, according to the results of a new study.
Researchers from Georgetown University Medical Center enrolled more than 600 children, ages 3-6, in a study to see if the strain of bacteria, Lactobasillus casei DN 114-001, could have an effect on common infectious diseases.
Parents in the study agreed to feed a drinkable yogurt regularly to their children. Half of the families received traditional yogurt and half received the probiotic yogurt, or yogurt that has beneficial bacteria. The parents did not know which type of yogurt they had.
By the end of the three-month study, the children who received the probiotic yogurt had 24 percent fewer gastrointestinal infections and 18 percent fewer upper respiratory infections than children who were getting regular yogurt.
"While it's probably the largest study [of its kind] in the U.S., it really wasn't done in the lab stetting," said Dr. Daniel Merenstein, lead author of the study published today in the European Journal of Clinical Nutrition.
Merenstein said the advantage of the study, which was funded by The Dannon Company, was that they didn't measure for markers of disease, but actual coughs and stomach troubles that parents would notice.
"It's data that's interesting to parents, this is data they reported," he said.
In February, The Dannon Company was ordered by a judge in Cleveland, Ohio, to pay up to $45 million for allegedly making unsupported claims about the health benefits of its probiotic yogurt.
The study didn't examine exactly how the beneficial bacteria in the yogurt prevented infections. But, Merenstein said, other studies have shown probiotics to have a general effect on the immune system and have improved asthma and eczema symptoms.
"Most yogurt has starter cultures, they have two probiotics that make it easier for people who have problems digesting milk," said Merenstein. "Besides that they don't do much for infections because they die pretty much when they hit the stomach."
Dannon has an obvious interest in selling yogurt, but Dr. Clifford Bassett, medical director of Allergy and Asthma Care of New York, said he's not terribly bothered by the fact that the company funded the study.
Parents Didn't Know Which Yogurt Went to Their Kids
"Any time you have a placebo controlled study, that's very powerful, that's the best you can have," said Bassett, who is also a clinical professor of medicine at Long Island College Hospital.
"Most, if not all of the studies done in the U.S. for drugs up for approval by the FDA are done with pharmaceutical backing," he said.
However, Bassett said the study opened up more questions about probiotics.
"It falls in the area of alternative or integrative medicine," said Bassett.
So far he said he has been convinced that other dietary measures such as omega 3 fatty acids and antioxidants have shown enough of an effect on the immune system to help with allergies. But Bassett said he's not yet convinced by this study to recommend probiotics to his allergy patients.
"We have to repeat it, we have to look at probiotics with different doses, and children of different ages," he said. "The question is, is it a probiotic effect, is it another effect?"
Merenstein himself had some questions after the study -- particularly why parents reported fewer infections, but they did not report fewer sick days.
"That's one of the goals," said Merenstein. "If you prevent parents from missing work, then you get into some interesting data."