They’re helpful or even necessary for some, but most of us should be wary of their claims
Sometimes our best intentions lead us down the wrong path. Take dietary supplements, for example — and there’s a good chance you do take them, considering more than half of American adults use supplements. Although they are a necessary and important part of a healthful routine for some individuals, supplements can also be ineffective or even harmful.
Dietary supplements come in an array of forms, from pills and powders to shakes. Check with your doctor before taking anything, but also consider why you want to take a supplement. If you avoid dairy products, for example, you might take a calcium supplement to make up for the calcium-rich dairy foods that your diet is missing. But “the vast majority” of people, says Michael McLeod, DO, associate chief medical officer at Concord Hospital, do not take supplements because they know that their diet lacks or is likely low on certain nutrients; they take a supplement such as calcium because they believe it will ward off osteoporosis. Or they take fish oil because they’ve heard that it can lower cholesterol or prevent heart attacks, despite the fact, McLeod says, that the American Heart Association does not recommend fish oil as a way to prevent cardiovascular disease or stroke.
For certain groups of people, and as treatment for a condition, supplements can be absolutely worthwhile. For example, taking folic acid before and during pregnancy reduces the risk of birth defects. Taking vitamin D because a blood test indicates that you are low on vitamin D can help protect bone health, as well as provide other benefits.
But supplements, including herbal ones, raise a number of concerns, such as potential interactions with medications. (A manufacturer’s assurance that an item is “all natural” does not necessarily mean the product is risk-free or beneficial to health.)
And keep in mind that the FDA does not oversee the effectiveness or safety of dietary supplements. The FDA takes action only after a supplement reaches the market “if there is a complaint filed against it or the product is found to be adulterated or misbranded,” says Elizabeth Boucher, MPH, RD, LD, a metabolic-bariatric surgery dietitian at the Elliot Center for Advanced Nutrition Therapy.
Unlike prescription drug manufacturers, supplement makers are not required to prove that their products are effective or safe. In fact, “the vast majority of supplements don’t have any evidence behind them” to prove their effectiveness, McLeod says.
Inconsistency and a lack of industry standards are also a problem. “I could send 100 people to the store [for supplements] and they could all come back with different concentrations,” McLeod says. “If two of them buy a 1,000-mg supplement, when we actually test them, one might only have 500 and one might have 1,500.”
The widespread availability of supplements for sale on the internet, along with ubiquitous marketing and rapid acceptance of products such as we’re experiencing with the current cannabidiol (CBD) craze, compounds the risk. “You’re buying things [but] you don’t know where they’re coming from and you really don’t know what’s in them,” McLeod says. Given the FDA’s limited oversight of the industry, “folks are able to sell products without submitting any evidence of purity, potency, safety or efficacy.” (Prescription supplements are a different matter. They are proven and FDA-approved.)
Some supplements contain caffeine and other stimulants, which can be dangerous for people with heart conditions, and some products contain potentially toxic concentrations of ingredients, Boucher says.
The same concerns arise with multivitamins, which many take to atone for less-than-ideal eating habits.
“There’s very little evidence,” McLeod says, that the typical American diet, with its fortified cereals, breads and milk and varied nutrients, leads to deficiencies that require a supplemental boost.
Plus, nutrients in food are better absorbed than nutrition that comes in the form of a supplement, Boucher says.
Overall, particularly if you don’t have a specific condition or need, supplements are best approached with a healthy dose of skepticism and caution. Even if you see an official-looking seal of approval on a supplement label, be aware that the manufacturer might have paid for it, Boucher says.
“I have [patients] who have taken as many as 10 to 15 or more supplements at a time,” McLeod says, based on manufacturer claims that a supplement will lower blood pressure or cholesterol, improve vision, ease depression or prevent other illness. “There’s just really no evidence that [supplements] do those things,” he says.
Not to mention, “a lot of them are really expensive,” McLeod says. Rather than buying supplements, he says, most of us would be better off spending our money on fresh produce from the local farmers market, a pair of sneakers and a gym membership.
For certain individuals, supplements are not a choice but a necessity. People who undergo weight-loss surgery, for example, must take supplements for the rest of their lives to prevent nutritional deficiencies. “It’s not a choice for them,” says Elizabeth Boucher, MPH, RD, LD, a metabolic-bariatric surgery dietitian at the Elliot Center for Advanced Nutrition Therapy. Left untreated, Boucher says, the nutrient shortages can have serious consequences for mental as well as physical health.
Still, all of us should proceed with caution. “Very little research” goes into supplement ingredients, Boucher says, and “many interactions can occur between vitamins and minerals in especially herbal supplements with prescription medications, so any time someone is interested in taking a supplement, I strongly encourage them to speak with their physician first and foremost, and if they’re seeing a dietitian, to discuss any particular interactions that this supplement may have.”