Pass the Probiotics

12.19.135:45 AM ET

The Multimillion-Dollar Multivitamin Hoax

Nearly half of all Americans take dietary supplements despite evidence that they may not help—and could actually harm—our health. Why I used to be one of them.

In the not so distant past, I had a voracious appetite for supplements. Most mornings, before digging into breakfast, I’d hoover up digestive enzymes, probiotics, and gelatin capsules filled with desiccated orange peels and papaya pulp. I spent $45 a month on those fruit and vegetable powders alone—“whole food” supplements designed to make up for the nutrients I was supposedly missing through my regular diet.

I grew up in a household where there was no shortage of unhealthy snack foods. My mother encouraged me to eat my vegetables and my Oreos. But when I went to college—that time of rebellion and rejection of past habits—I worked at an organic juice bar and was soon adopted by its hippie owners. They introduced me to the dangers of toxins and free radicals, the alleged benefits of eating organic, and to the knowledge that kale contained more vitamins than any other leafy green vegetable (this was in 2004, before kale became as common as iceberg lettuce). Before long I was peddling goji berry juice, prattling on to friends and family about why they should spend $30 for a bottle of this “superfood” from the Himalayas.

I had become an evangelist for uncommon foods—but food wasn’t enough. Because multivitamins weren’t “natural,” I started swallowing something called Juice Plus, pills packed with “juice powder concentrates from 25 different fruits, vegetables and grains.” It would, I was told, boost my immune system, stave off wrinkles, prevent cancer, and make my bowel movements perfectly symmetrical. Sure, it was expensive, but I was investing in my health!

Embraced by the community, I trusted the high priests of this new dietary lifestyle. Intuitively it made sense that my body would absorb nutrients if they came from dehydrated fruits and vegetables (they’re still fruits and vegetables, after all) instead of chemically formulated, over-the-counter multivitamins. According to Juice Plus, studies demonstrated that their product would help provide me with “healthy gums,” a “healthy immune system,” and would protect my DNA from “oxidative stress” (whatever that is). I was impervious to counter-evidence; I was eating the pills and drinking the Kool-Aid. Had I even checked Wikipedia, I would have discovered widespread skepticism about the company’s claims: “Doubts have been raised about the advertised benefits of Juice Plus by Memorial Sloan-Kettering Cancer Center, University of California Berkeley, Center for Science in the Public Interest, and other sources.”

But what of all of those clinical studies? With a little more research and a little less faith, I would have found on Juice Plus’s own website a concession that “much of the [research] featured on this page was funded” by grants from...Juice Plus! (“University faculty seeking to apply for a grant should contact the company directly at”)

I existed on the fringes of what is broadly called the “alternative medicine” universe. Doctors don’t prescribe this stuff, but then again doctors are probably in the pocket of big pharmaceuticals, right?

Nearly half of all Americans ingest a multivitamin pill every day—a more respectable supplement. Indeed, medical professionals have urged us to take multivitamins for years, but new research indicates that not only are the pills mostly unnecessary, but they could actually do harm those taking them. “We believe that the case is closed—supplementing the diet of well-nourished adults with (most) mineral or vitamin supplements has no clear benefit and might even be harmful,” reads an editorial published in the esteemed Annals of Internal Medicine this week. “These vitamins should not be used for chronic disease prevention. Enough is enough."

Based on three studies examining multivitamins’ links to cancer prevention, heart health, and cognitive function, the research is a blow to the $28 billion vitamin industry—and the estimated 40 percent of Americans who shovel money into it. But skepticism of the effectiveness of vitamin supplements is hardly new. In his 2013 book Do You Believe in Magic, Dr. Paul Offit pointed to a handful of major studies over the past five years that showed vitamins have made people less healthy. “In 2008, a review of all existing studies involving more than 230,000 people who did or did not receive supplemental antioxidants found that vitamins increased the risk of cancer and heart disease.”

But these studies haven’t disabused most Americans of the notion that vitamins are beneficial and necessary. So why do we insist on believing health claims based on shaky—and sometimes nonexistent—science? “I think this is a great example of how our intuition leads us astray,” Steven Salzberg, a professor of medicine at Johns Hopkins, told NPR. “It seems reasonable that if a little bit of something is good for you, then more should be better for you. It’s not true. Supplementation with extra vitamins or micronutrients doesn’t really benefit you if you don’t have a deficiency.”

Like so many others, I had intuition—and faith—that my doctors were shielding me from the truth, that my supplement routine would help my health. Alas, it only hurt my bank balance.