What’s the scoop on probiotic yogurt?
The more we learn, the more we realize how complex they are
Can all yogurts deliver health-promoting probiotics? The answer is a resounding no.
With all the buzz about the benefits of probiotics these days, yogurt is being touted as an effective and relatively inexpensive way to deliver these “good” bacteria into your body. Exciting research is showing the links between gut health and seemingly every other health condition, from the brain down to the joints of your arthritic big toe. Health-conscious people hope probiotic-packed yogurt will create a healthy ecosystem in their intestines — and spread its benefits to the rest of the body.
If only it were that easy. Unfortunately, the more we learn about probiotics, the more we realize how complex they are. And we have a long way to go in learning how to use them to their fullest potential. Especially if you’re hoping for specific health benefits, like better immunity, weight loss, fewer colds and Irritable Bowel Syndrome (IBS) symptoms, you need to be careful about the type of probiotic you’re buying.
Take your average supermarket brand of yogurt. The first thing to realize is that not all yogurt is “probiotic yogurt.” It’s true all yogurt is made with bacteria, which is why you’ll see “live active cultures” listed on the carton.
But yogurt labelled “probiotic” has at least a billion added live probiotics. All probiotics have common health benefits, no matter which strain of bacteria they contain. These include making our guts less hospitable to bad bacteria and making our gut microbial community and intestine healthier. But some offer more specific benefits that can address specific health conditions.
We recently studied common supermarket probiotic yogurts to learn which could be the most effective for offering these benefits and targeting specific health conditions. Danone’s Activia has the most research demonstrating beneficial effects for minor stomach issues such as pain or bloating. But none of the other products in our study have been tested for stomach issues, so we can’t say this is the only yogurt offering such benefits.
Two products in our study — DanActive and BioBest — had strains that were shown to decrease risk for the common cold. However, the dosage in BioBest was 20 times lower than the dosage tested (and found effective) in a clinical trial. So we simply don’t know whether a serving a day of this yogurt would help to ward off colds. For a fuller list of brands, check out our paper in the journal Nutrients.
Indeed, one of the most important findings in our study was the lack of research on probiotic foods. And much of what does exist is funded by the companies that make these products.
Learning from traditional cultures Good bacteria have been a staple of the human diet for thousands of years. If you look around the globe, almost every region has some kind of traditional fermented food that supplies them.
In Germany, it’s sauerkraut; in Korea, kimchi, and in Russia, kefir. Fermented foods often contain complex groups of good bacteria that are hard for scientists to define. Research shows a link between fermented dairy foods and reduced risk of type 2 diabetes and other health benefits. But in general fermented foods are tough to study and cannot be currently considered probiotics.
That said, the kefir (fermented milk) products in our study, from Liberte and Iogo, stood out because they had the greatest variety of probiotic strains and often the highest dose. Some research suggests that strain mixtures could be more effective than single strains, but there’s no incentive for yogurt companies to use multiple strains.
Finally, while probiotic yogurt is healthful for everyone who tolerates dairy, all the studies in the world can’t predict with perfect accuracy what will happen if you take a probiotic.
But just know that if you do see improvement with a certain probiotic product, you must keep taking it if you want to continue receiving the benefit. If you are immunocompromised or have a critical illness, ask for a physician’s advice before taking probiotics. Mary J. Scourboutakos is a post-doctoral researcher and assistant professor; Elena Comelli is the Lawson Family Chair in Microbiome Nutrition Research at the University of Toronto. Doctors’ Notes is a weekly column by members of the U of T Faculty of Medicine. Email doctorsnotes@thestar.ca.