Every year, half of all Americans take some kind of pill as insurance against their diets.
But recently, researchers have noticed a surprising trend: Use of some of the most popular supplements is waning, possibly because of recent reports questioning their benefits and raising awareness about risks. In a study by the independent research group ConsumerLab.com, calcium supplementation declined among women, from 58% in 2012 to 46% in 2013 . Vitamin C purchases were off by 4.2%. Even sales of fish oil — once the hottest supplement on the market — dropped, according to the report.
The one category where supplementation is actually growing? Probiotics, or live bacteria that work by “recolonizing the small intestine and crowding out disease-causing bacteria, thereby restoring balance to the intestinal flora,” according to ConsumerLab.com. From 2012 to 2013, use of probiotics rose from 31% to 37% among regular supplement users.
Christopher Mohr, a nutritionist who founded MohrResults.com, a nutrition counseling company in Louisville, can attest to the growing demand. “There has certainly been an increased interest among clients,” he says. “A good number of scientific studies support the inclusion of probiotics in our diet, and these stories get picked up by the media, leading consumers to learn more about them.”
Indeed, some medical research suggests numerous and broad applications for probiotics, such as easing irritable bowel syndrome (IBS) and stomach distress associated with taking antibiotics. On the other hand, the National Institutes of Health takes a more conservative stance, concluding that “although some probiotic formulations have shown promise in research, strong scientific evidence to support specific uses of probiotics for most conditions is lacking.”
Canadian researchers have linked probiotic supplementation to lower levels of anxiety. According to study authors, the probiotic “L. rhamnosus (JB-1) reduced stress-induced corticosterone and anxiety- and depression-related behavior” in lab experiments. “Together, these findings highlight the important role of bacteria … and suggest that certain organisms may prove to be useful therapeutic adjuncts in stress-related disorders such as anxiety and depression,” they added.
Weight loss is another possible application. A study in December’s British Journal of Nutrition found that women supplementing their diet with probiotics were significantly more likely to lose weight (nearly 11 pounds on average) compared with those taking a placebo (just 5.7 pounds) over a 12-week period.
While probiotic use is generally considered safe, not all supplements are created equal.
“In our testing, some products did not contain the amount of organisms that they claimed,” says Tod Cooperman, president of ConsumerLab.com. In general, capsules must contain more than 1 billion CFUs (colony-forming units) to be effective.
The measurements are taken at the manufacturing site, but because of improper shipping or storage in heat or humidity, the number of CFUs may be half of what the label claims by the time the supplement reaches consumers. In the ConsumerLab.com tests, Nature Made Digestive Health Probiotics, Culturelle and Align Probiotic Supplement all scored high marks.