We’ve all heard that there can be great health benefits to eating yogurt, but what makes yogurt so special? The main health benefits of yogurt are due to the fermentation process involved in making it (for more about fermentation, see Real Food Profile: Fermentation—Nature’s Preservative). But not all yogurt is created equal.
No, we’re not talking about the added sugar or protein content that can be found in many commercial yogurt products (although that is definitely something to watch out for—you won’t get healthier by eating added sugars). We’re talking about the live active cultures that we’ve heard so much about.
Live active cultures are the living bacteria that convert milk into yogurt during fermentation. To make yogurt, something called a starter is introduced into the milk to get the fermentation process going. This “starter” includes bacteria that consume the lactose sugar in the milk, transforming that sugar into lactic acid. As this process continues, the milk gradually becomes more acidic and begins thickening into yogurt.
Since yogurt’s ability to enhance the gut microbiome is directly dependent on the bacteria in the yogurt being alive and functional, you would naturally expect that the yogurt you’re eating contains those live active cultures, but in fact not all dairy yogurt contains live active cultures.
Here’s the story: It’s generally the case that the milk yogurt is made from is pasteurized (heat-treated) to kill microorganisms that would otherwise cause it to spoil. But in order to avoid having to refrigerate the product afterwards at every step of the process of storing it and transporting it to the store, some brands also pasteurize the yogurt itself, which kills all beneficial bacteria.
The FDA only considers a food as “yogurt” when certain things are present and posted on its label. And while the FDA specifies that the culture used to make the yogurt must contain the lactic acid-producing bacteria Lactobacillus bulgaricus and Streptococcus thermophilus (1), it does NOT specify that those cultures must still be alive at the point that the yogurt is delivered to the grocery store.
So how can we be sure that the yogurt in our bowl is, well, alive? The easiest way is to look for the Live & Active Cultures (LAC) seal.
Display of this seal is voluntary, so it’s quite possible that a yogurt which has live and active cultures does not have the seal. Normally, however, the manufacturer would state somewhere on the label that the yogurt “contains live and active cultures”, and the FDA requires that when that statement is made the yogurt must have contained a specified amount of live bacteria at the time of manufacture. The FDA further requires that if the dairy ingredients have been treated in a way that kills the bacteria, the manufacturer tell the consumer that the yogurt “does not contain live and active cultures.” But when that’s the case then it’s also a safe bet that the print size of that statement will not necessarily be reader friendly.
If you’d like to know which bacteria the yogurt contains, you can find it listed on the ingredients label. All yogurts must contain the two main cultures, species L. Bulgaricus and S. Thermophilus, but the manufacturer determines which subspecies are used as well as any additional species. Within those two species of bacteria there is immense variation. Some subspecies are faster at converting lactose to lactic acid, and some impart more of that tangy flavor. The taste, texture and the probiotic benefits are all affected by the use of different bacteria, and a typical yogurt-making culture contains four to six strains. Yogurt manufacturers may also add additional “probiotic” species that don’t majorly impact the flavor but can be claimed to improve intestinal health (ex: Lactobacillus acidophilus, Bifidus regularis, and Lactobacillus casei) (3).
All things considered, your favorite yogurt’s flavor as well as your brand preferences probably have a lot to do with the specific proprietary, bacterial blend.
If you’re interested in controlling exactly what goes into your yogurt, or just like experimenting in the kitchen, you could try your hand at creating this gut-friendly food at home. This may seem daunting but it’s really pretty easy and worth the effort if you have the time to try it.*
Yogurt is yet another fermented food that can contribute to health while also being a source of protein, calcium, phosphorus, and B vitamins like riboflavin and B12. Incorporating yogurt into your diet is easy and delicious. Just be sure that your choices contain “Live Active Cultures”!
*With this as with any recipe, it’s important that you follow instructions carefully, with care to keeping unhealthy bacteria at bay.