Yogurt is a cultured or fermented milk product that is soured and thickened by adding specific lactic acid-producing cultures to milk. The basic cultures or probiotics used to make yogurt are Lactobacillus bulgaricus and Streptococcus thermophilus. Additional probiotics are often added. Common ones are Lactobacillus acidophilus, Lactobacillus casei, and Bifidus, all of which may help to maintain the balance of bacteria needed to boost the immune system and promote a healthy digestive tract. Evidence is mounting that bacteria are critical to maintaining normal gastrointestinal and immune system function. Sonya Angelone, MS, RDN, CLT, San Francisco-based nutritionist and spokesperson for the Academy of Nutrition and Dietetics, said. 70 percent of a person’s immune system is in the gut; “Healthy bacteria, such as the probiotics found in healthy yogurt, are the gut’s first line of defense," she said. The American Gastrointestinal Association recommends yogurt for digestive health and to ease constipation, diarrhea, and other intestinal problems. A study published in the February 2009 issue of the Journal of Digestive Diseases found that probiotics help improve lactose digestion, prevent constipation, and irregularity, and may have healing effects on the intestinal tract. Perhaps skewing the results, studies on the digestive benefits of yogurt are funded mostly by yogurt companies. It’s clear, though, that one of the best and most available ways to regularly get probiotics is by eating yogurt. When high concentrations are needed, your doctor may give you a prescription for probiotic pills.
Live and Active Cultures in Yogurt
Probiotics are living microorganisms that help stop bad or undesirable bacteria from overgrowing in the gut. They may help fight diarrhea, irritable bowel syndrome, and colon diseases. If you’re buying yogurt for its health benefits, no matter what its base ingredient, the key to making the right choice is being sure it contains live and active cultures. The label on the container will tell you what probiotics are in the yogurt. Some yogurts carry the National Yogurt Association’s (NYA) “Live and Active Culture” seal, but if that label is not on the container, look at the ingredient panel. “Yogurt is a healthy addition to the diet because it contains calcium, protein, and active cultures,” said Lori Rosenthal, MS, RD, CDN, a registered dietitian in the department of surgery at the Montefiore Medical Center in New York. “But it’s not a major cure-all for GI disorders because it just doesn’t have enough cultures to fight serious problems.”
Yogurt Standards
The NYA has established standards for probiotics. For yogurt to be healthy, it must have at least 100 million cultures per gram at the time of manufacture. Frozen yogurt must contain 10 million cultures per gram. If these minimums are met, the Live and Active Cultures seal may be on the label.
Traditional Yogurt
You’ll find traditional yogurt in numerous brands and even more flavors. When choosing yogurt, look at calories, fat, and sugar content as well as important nutrients, like calcium. A non-fat or low-fat (2 percent) plain, unflavored yogurt with vitamin D and at least 200 mg of calcium is the healthiest choice. Beware of processed sugars — they’re unhealthy and can cause inflammation, said Rosenthal. Sugar should be less than 15 grams per serving. Keep in mind that yogurt with fruit (whether on the bottom or mixed in) is going to be higher in sugar. Rosenthal suggested buying plain yogurt and adding in your own fresh fruit. Stay away from yogurts with high fructose corn syrup and artificial sweeteners; added sugar alcohol is intended to keep calories low, but it’s also unhealthy and should be avoided, she added. The liquid found on the top of a container of yogurt is whey and can be mixed back into the yogurt. Either way, it’s a source of calcium and you want to eat it. A good traditional yogurt should contain 30 to 50 percent of your daily calcium requirement. If you see the words heat-treated, steer clear. That signals that the live and active bacteria that help replenish bacteria in the digestive tract have been killed.
Greek Yogurt
The difference between traditional and Greek yogurt is in the processing. Greek yogurt is strained three times instead of twice, giving it a creamier texture. The whey is removed in the straining process and, as a result, a serving may only provide about 25 percent or less of your daily calcium needs. On the plus side, Greek yogurt often has more protein grams per serving. Always check labels to find out what cultures have been added.
Frozen Yogurt
Some frozen yogurts have no live and active cultures, so while they taste good, they won’t benefit digestion. However, if probiotics are in the yogurt, the freezing process won’t kill them. It will simply put them into a dormant state until warmed and eaten. Again, if in doubt, look for the words Live and Active Cultures.
Soy Yogurt
Soy-based yogurt is a good alternative for vegetarians and vegans who don’t eat dairy. The amounts of protein, calories, and probiotics are similar to other yogurts, providing healthy additions to the digestive tract.
Yogurt: Other Blends
Whipped yogurts are expensive and have less protein than regular yogurt. Yogurt drinks are an option, but contain higher levels of sugar, and yogurt-covered snacks are loaded with sugar and calories and have no beneficial contents. Yogurt should be part of a regular, healthy diet. “For a healthy person,” said Angelone, “yogurt can help maintain a healthy digestive tract, but when somebody has a medical condition or is taking antibiotics, it won’t hurt, but it just may not be enough.”
