Is Yogurt Really That Good for You?

Are probiotics a prescription for glorious guts or just a gimmick? Until his death in 1916 at the unremarkable age of 71, the Nobel Prize-winning...

Are probiotics a prescription for glorious guts or just a gimmick?

Until his death in 1916 at the unremarkable age of 71, the Nobel Prize-winning Russian scientist Ilya Metchnikoff promoted a theory for prolonging human life. His recipe for longevity was simple: yogurt. Metchnikoff thought that the consumption of the bacterial culturesenabled Bulgarian peasants to live for an average of 87 years and he sought to bring its transformative qualities to the West.

A half decade later, in 1977, Dannon made a TV commercial for its yogurt repeating a similar claims, only this time it was Soviet Georgians who prolonged their lives by eating spoonfuls of creamy, fermented milk. Many of these longevity claims have been refuted, but yogurt companies continue to market the bacteria that break down lactose and turn liquid milk into lumpy yogurt-like Streptococcus and Lactobaccilus-as beneficial.

These probiotics, they say, can regulate digestive health, lower cholesterol, strengthen bones, and make you and your stomach happier. Consumers are encouraged to imagine good, little critters colonizing their stomachs. The stuff is allegedly so good, in fact, that yogurt containers seem like a better fit in the medicine closet-alongside Nexium, Prilosec, and Protonix-because of their medical-sounding prospects of transforming your digestive tract.

We've been introducing bacteria into our stomachs for millennia-not to mention the some 50 trillion microbial cells and thousands of species of microflora in the gut already-but many of the scientific-sounding claims surrounding probiotic bacteria have nothing to do with the actual science itself. While some recent studies have suggested thatLactobacillus bacteria aid in digestion and play a role in our body's immune defenses, many of the contemporary claims seem almost as exaggerated as Metchnikoff's longevity theory.

As the list of digestive ills that probitoics can allegedly cure expands, so do the number of probiotic drinks, cereals, and shakes. Now, there's probiotic dog food, probiotic ice cream, and probiotic treatments for farm-raised salmon. The only problem: Some so-called probiotic bacteria don't contain strains medically recognized as beneficial. As one expert told Tara Pope Parker, "To say a product contains Lactobacillus is like saying you're bringing George Clooney to a party. It may be the actor, or it may be an 85-year-old guy from Atlanta who just happens to be named George Clooney."

And even when products do contain beneficial bacteria, the bacteria are sometimes dead. This is especially true when they're frozen in "probiotic" ice cream.

The lack of regulatory oversight about these kinds of nutritionistic health claims in the United States has led to litigation. As Marion Nestle pointed out on The Atlantic Online, lawyers won a large class-action settlement against Dannon in September for claims that Activia regulated digestion and stimulated the immune system. While food companies worked to get an approval from the European Standards Agency, the agency rejected all "probiotic" strains of bacteria under consideration last week.

For now, no bacterial strain has proven to be the all-purpose boost, the key to the fountain of youth, a hundred years of yogurt solitude. Don't let that stop you from enjoying the mouth-tingling taste of bacteria-laden foods like fermented yogurt, kim chi, or Lambic beer.

Photo by Jeff Potter.