This week, the Annals of Internal Medicine—one of the world’s leading medical journals—published three studies evaluating the benefits of vitamins and dietary supplements.
The first study determined whether healthy people who received daily multivitamins had a lesser incidence of cancer or heart disease and whether they lived longer. The study was quite large, involving about 400,000 adults. Study participants were randomly divided into two groups: One group received daily multivitamins; the other didn’t. The authors found no difference in any medical outcome.
The second study examined about 6,000 men older than 65 to see whether daily multivitamins improved cognitive performance or verbal memory. The group that received multivitamins was indistinguishable from the group that didn’t.
It shouldn’t be surprising that megavitamins have consistently been shown to do harm. The lesson is clear: Don’t fool with Mother Nature.
The third study examined about 1,700 men and women with a history of a heart attack to see whether multivitamins could prevent another cardiac episode. Patients were followed for about five years. The study was limited by a high dropout rate, but again, multivitamins did nothing to prevent heart attacks in those at highest risk.
In the editorial that accompanied these studies, the authors summarized the evidence. “Beta-carotene, Vitamin E, and possibly high doses of Vitamin A supplements are harmful,” they wrote. “Other antioxidants, folic acid, and B vitamins, and multivitamin and mineral supplements are ineffective for preventing mortality or morbidity due to major chronic diseases.” In other words, megavitamins (which contain quantities in excess of the Recommended Daily Amount, or RDA) were potentially harmful, and multivitamins (which contain at or around the RDA) were useless. The title of the editorial wasn’t subtle: “Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements.”
Although CNN reported the results of these studies as breaking news, there’s nothing new about them. Since 1992, studies of multivitamins have failed to show benefits and megavitamins have shown a paradoxical increased risk of cancer and heart disease. The other thing that wasn’t new was the industry’s response through their two major lobbying groups: the National Products Association and the Council for Responsible Nutrition. Industry lobbyists typically respond to these kinds of studies in predictable ways.
First, they claim that studies weren’t done using the right amount of vitamins or the right brand of supplements or tested for the right length of time. A definitive study, they argue, just hasn’t been done. Researchers sometimes refer to this as the “you-didn’t-do-the-study-in-a-closed-container-under-water” argument.
Second, lobbyists for the industry will argue that the right population wasn’t studied. “It is pretty common that in this day and age, with the lifestyle many of us lead, that we don’t always take the time to have a balanced diet,” said Cara Welch, senior vice president of the Natural Products Association, “and even if you do have a balanced diet, you can still have nutritional deficiencies.” One is left to assume that the 400,000 or so people in the first study weren’t representative of the general population—weren’t among the “many” who don’t eat a balanced diet.
Third, supporters of the industry will claim that investigators were in the pocket of Big Pharma, which presumably doesn’t want the American public to know about the value of supplemental vitamins. The dietary supplement industry has successfully positioned itself as the little guy versus the big guy: David to Big Pharma’s Goliath. Their success is all the more remarkable in that supplement makers are the big guy. Both Pfizer and Hoffman-LaRoche are major players in what is now a more than $28 billion a year business. The supplement industry is Big Pharma.
The most remarkable reaction to these studies, however, came from Duffy MacKay, who represents the Council for Responsible Nutrition and who broke new ground. “While those in the ivory tower may say that people just need to eat their sardines and salads,” said MacKay, “in the real world, there are nutrient gaps.” This statement is revealing in several ways.
By contrasting the phrase “ivory tower” with “real world,” MacKay was suggesting that academics are critically disengaged from what’s happening on the ground. The hundreds of thousands of participants in the first study, however, weren’t taken from cages in the basement of academic centers. They were taken from the streets: real-world people living real-world lives. To determine whether multivitamins were useful, the authors divided subjects into two groups, making sure that both groups were similar with regard to medical background, health-care-seeking behavior, and socioeconomic status. This allowed them to isolate the variable under study: receipt of multivitamins. It’s exactly how James Lind did his study in the mid-1700s when he climbed aboard the HMS Salisbury and found that fruit juices prevented scurvy. And it’s exactly how all epidemiologists do studies when they’re trying to figure out whether something works.
The other part of MacKay’s rebuttal that was interesting was the phrase “sardines and salads.” The implication was that people could get what they needed from foods, but they weren’t going to enjoy doing it. Better to get them from supplements. This positioning is arguably the greatest success of the dietary supplement industry—the notion that vitamins and minerals present in pills are processed and presented to the body in a manner identical to foods. Indeed, that concentrated supplements are better than food given that there are some foods that you’re never going to eat.
The ingestion of supplements, however, is anything but natural. Although popping 1,000 milligrams of Vitamin C (present in forms as delightful as gummy bears) might seem like no big deal, you would have to eat 14 oranges or eight cantaloupes to achieve the same amount. It’s hard to eat eight cantaloupes at one time. That’s because you have to bypass your stomach’s satiety level. Maybe our stomachs are only so big for a reason. So it shouldn’t be surprising that megavitamins have consistently been shown to do harm. The lesson is clear: Don’t fool with Mother Nature.
Despite their protests, industry lobbyists have no cause for worry. During the past 20 years—when studies showing the uselessness of multivitamins and the potential harms of megavitamins have been performed—more and more Americans have taken vitamins and supplements. The industry knows that it can market the results of these studies away—that people are far more likely to watch commercials on television or read banner ads on the Internet than pay attention to medical journals, whose press releases survive at most one news cycle. The industry should be comforted to know that we’ll continue to ignore the overwhelming amount of evidence that shows that dietary supplements aren’t what we think they are. Because the simple truth is that we need to believe the hype, need to believe that there is something readily available in pill form that will help us to avoid the ravages of cancer, heart disease, and aging, even if the opposite is true.