Answer :Simin Nikbin Meydani, DVM, PhD, professor of nutrition at the Friedman School and associate director of Tufts Jean Mayer USDA Human Nutrition Research Center on Aging, responds:
The nutritive value of yogurt or frozen yogurt is based on the ingredients in the yogurt, so it will be slightly different for frozen yogurt made by different companies. The labels should provide the nutritional information. [Since frozen yogurt is a dessert, its typically sweetened; make sure to also check the label to see how much added sugar youre getting.]
Yogurts and frozen yogurts can contain live active cultures. Manufacturers might add extra healthy bacteria (such as L. acidopihilus, Bifidobacteriumor and others) for their health effects, but not all yogurts have these extra probiotic bacteria. Although the flash-freezing technique used in the production of frozen yogurt, unlike slow freezing in a freezer, should not kill the live cultures, there is no guarantee that this wont occur.
As a result, the number of bacteria in frozen yogurt is usually lower than that in the yogurt it was made from. Different yogurts and frozen yogurts are made with different types of live cultures and probiotics, however, and the levels that remain in frozen yogurt depend on the numbers that were in the yogurt and on the heartiness of the specific bacteria that was used.
The National Yogurt Association sponsors a voluntary labeling program for frozen yogurt; look for the Live and Active Cultures seal on containers of frozen yogurt. If the yogurt doesnt have the label, contact the manufacturer and ask what types of bacteria their product contains and at what level.
Some frozen yogurts may be better sources of probiotics than some regular yogurts. The National Yogurt Association standard for a live active culture frozen yogurt is 10 million cultures per gram at time of manufacture; for yogurt it is 100 million.