Q. How do the nutrition and probiotic benefits of kefir compare with those of Greek yogurt?

A. Rosy Rojas, an intern at Tufts’ Frances Stern Nutrition Center, answers: “Kefir and Greek yogurt are two trendy probiotic dairy products that are actually fairly similar nutritionally speaking. Both products are great sources of calcium, potassium, zinc, vitamins B12 and B6, and protein; however, there are some notable differences. Greek yogurt has more than twice as much protein as kefir. This helps makes Greek yogurt a useful tool for satiety, weight loss and maintaining or building lean body mass. Consequently, the higher protein also makes Greek yogurt higher in calories compared to kefir. Another nutrition difference is that kefir tends to have more calcium and potassium than Greek yogurt. For these reasons, kefir may marginally be a better choice for individuals hoping to prevent osteoporosis or increases in blood pressure.

“Both Greek yogurt and kefir are worthy sources of probiotics. But, unlike Greek yogurt, kefir has a greater number and wider variety of beneficial bacteria, and also contains helpful yeast. The abundance of probiotics in kefir is thought to provide bigger health benefits than Greek yogurt, particularly in relation to gut health. Other health claims, such as cholesterol reduction and cancer prevention, for probiotics like kefir and Greek yogurt have received a lot of hype in recent years. But there currently is not enough evidence to fully support these health claims.

“Kefir and Greek yogurt are enjoyable on their own, but can also be topped with fruit, added to smoothies, and even used to substitute for other dairy items (e.g., sour cream, mayonnaise, heavy cream, etc.) in sauce and condiment recipes.”