Yummy! The 101 on yogurt and its benefits

We all know eating yogurt can be healthy, but did you know it could help everything from your cholesterol to your immune system? TODAY Diet and nutrition editor and iVillage contributor Madelyn Fernstrom has all the perks that can be found in this one little package.

We all know yogurt can be healthy. Like all dairy products, it is a good source of protein and calcium, and choosing nonfat, or at least low-fat yogurt provides all the benefits without the artery-clogging animal fat (it does come from a cow). Just 1 cup has about 1/3 of the daily calcium requirement and roughly 10 grams of protein (15-20 percent of daily requirements). And many people who are lactose intolerant can eat some yogurt because much of the milk sugar is gone in yogurt and converted to lactic acid.

But if you've walked down the dairy aisle of your grocery store lately, you'll notice that the different yogurt options seem endless. There is an explosion of new products and not just low-fat and soy, but custards, liquid (kefir) and smoothies. The good news is that many of these yogurts have added health benefits as well. Yogurt is a good carrier for "value added" ingredients. It can mask taste and texture of other compounds, since it has a strong taste and thick texture to start with. So whether it's extra good bacteria (probiotics), fiber, phytosterols (plant compounds), many yogurts have these "value added" ingredients. Not sure how to choose? Avoid yogurt with added fruit toppings — this is where you're going to find added sugar. Instead, look for packaging with buzz words like "live cultures" or "active cultures" ... and see more specifics in the categories below.

Yogurt 101 What is it? A dairy product produced by bacterial fermentation of milk, it is a natural biological process, like wine is from fermented grapes. "Good" bacteria are put into milk, under controlled conditions of temperature. The bacteria ingest the milk sugar (lactose), for energy, and then release lactic acid as a "waste" product. It's the lactic acid that acts on the milk protein to give yogurt its characteristic "tanginess" and texture. It changes the milk protein to produce a thicker texture and tangy taste. This is safe, since the whole biological process is acidic (i.e., lactic acid), so bad bacteria don't grow during the process. Most yogurt is from dairy (from a cow), but soy yogurt is also available for those with lactose intolerance or milk-protein (casein) allergy.

Yogurt's been around for more than 4000 years, but there's no clear idea of where it was first "discovered." Eaten all over the world, it was always "plain" until the 1930s, when a fruit jam was added to help prevent yogurt from spoiling too soon. A patented process, it was introduced to the U.S. in the late 1940s by the now familiar Dannon. Weight lossThere is a high amount of protein in these yogurts for few calories (because the extra milk liquid — whey — has been filtered out). It's about 100 calories for 6 ounces and 22 grams of protein. By comparison, a 100-calorie protein bar usually has about 6-8 grams of protein, so you're getting more than twice the amount of protein in the yogurt. Protein is biologically VERY satisfying, and helps curb appetite on less food (compared to the same calories found as carbohydrates).

    High cholesterol
    This product has 2 grams of phytosterols, which have nothing to do with the yogurt. The yogurt is only a carrier. It must be consumed daily for an effect on cholesterol levels (measured by blood test). It acts to block cholesterol you are eating, so consume with meals (preferably if you're eating higher cholesterol at that meal). This can have a modest effect, when used regularly. However, this has no effect on the other source of body cholesterol (what your body makes in the liver) and does NOT replace medical care — do not compare this with a statin drug!! Again, it only blocks cholesterol absorption in the digestive track — it doesn't get in the body!

    • For high cholesterol: Promise ACTIV shooters

    Irritable bowel and constipation
    The extra probiotics (good bacteria) added to these yogurts enhance the action of the good bacteria already in the yogurt. It's another strain of the bacteria, so you have more benefit, with more good bacteria per serving. This can affect transit time in gut — good for regularity. This is still somewhat controversial — compared with what yogurt does "normally" — but Activia comes with a money-back guarantee.

    • For irritable bowel and constipation: Activia, Activia-light (no sugar), Yo-Plus

    Immune function
    The probiotics (healthy bacteria) in these yogurts have been shown to boost immune function, like increase white blood cell count, one of the cells that help fight infection. Other studies show some effect on antibodies in the gut. Though these are not definitive, it certainly can't hurt.

    • Immune function: DanActive immunity

    DessertTo tame a sweet tooth, yogurt can help — but read the label to check for calories and fat. Cool packaging is eye-catching, but "fun" yogurts are not all the same. Avoid "fruit" yogurts — add your own fresh or frozen (no sugar added) berries — and save calories and extra sugar, and get a little fiber as well.

    Look for lower fat and low sugar. Some of the Dannon "pie" yogurts are low-fat and low in sugar — a big help for many. Also, frozen yogurt, with or without sugar, is a preferred choice to ice cream — a great taste, with much lower fat.

    • Dessert: Yoplait with crunchies; Yoplait thick & creamy (pudding-like); Dannon "Pie" yogurts; low-fat sugar/fruit-added organic yogurt; Gogurt (yogurt in a tube); blueberries, raspberries, strawberries; Grape Nuts cereal