For years, scientists have been saying that there isn’t much evidence to recommend vitamin supplements for most people, and a growing body of research suggests that most pills are useless and don’t necessarily make us healthier.
However, the message has not arrived. More than half of US adults take dietary supplements regularly, fueling an industry worth approximately US$50 billion a year.
Enough is enough, the researchers say. In the latest repudiation of vitamin supplements, the US Preventive Services Task Force (USPSTF) issued new recommendations, formally stating that there is insufficient evidence to suggest that supplements provide benefit in preventing cardiovascular disease and cancer, the two leading causes of death in the US.
The new USPSTF recommendations, the first for vitamin supplements since 2014, were not established lightly, but only after considering 84 studies evaluating the effects of supplements, involving nearly 740,000 participants in total.
“Unfortunately, based on the existing evidence, the task force cannot recommend for or against the use of most vitamins and minerals and calls for more research,” says USPSTF Acting Chief Scientific Officer John Wong.
However, there are some important caveats to keep in mind, as not all of the findings were equivocal.
The new recommendations regarding insufficient evidence of benefit apply only to healthy adults without nutritional deficiencies, and do not apply to people who are pregnant or trying to become pregnant, who are advised to take folic acid supplements.
Additionally, although the USPSTF found that the evidence was generally unclear for supplements in general for healthy, non-pregnant adults, for two products in particular, the data was less ambiguous: vitamin E and beta-carotene, both of which are not recommended. drink. .
“We found that there is no benefit to taking vitamin E and that beta-carotene may be harmful because it increases the risk of lung cancer in people who are already at risk,” says USPSTF Vice President Michael Barry.
Aside from those limitations, though, the new recommendations essentially reaffirm what many scientists have been telling us for years: There’s no real proof that these pills are good for us.
But at the same time, barring rare cases, like when supplements are contaminated with hidden pharmaceutical ingredients, there’s not much to suggest they’re bad for us, either.
“The Task Force is not saying ‘Don’t take multivitamins,'” says Dr. Jeffrey Linder, chief of general internal medicine at Northwestern University Feinberg School of Medicine.
“But there’s this idea that if these were really good for you, we’d already know.”
Linder, co-author of a new editorial commentary on supplement use and the new USPSTF recommendations, says there are good reasons why people believe supplements will be good for their health.
“In theory, vitamins and minerals have antioxidant and anti-inflammatory effects that should decrease the development of cardiovascular disease and cancer,” explains the commentary, co-authored by Northwestern University researchers Jenny Jia and Natalie Cameron.
“Eating fruits and vegetables is associated with a decreased risk of cardiovascular disease and cancer. It stands to reason that key vitamins and minerals could be extracted from fruits and vegetables, packaged into a pill, and people could avoid the difficulty and expense of maintaining a balanced diet.”
Unfortunately, all the evidence we have doesn’t really confirm that assumption, suggesting that, for reasons we don’t yet fully understand, micronutrients isolated from other natural dietary components don’t seem to offer the same health benefits as when combined. You are wrapped and eaten in food.
Even more unfortunate, the dietary supplement industry exploits people’s misunderstanding on this ambiguous point, spending hundreds of millions of dollars each year to perpetuate false beliefs about the powers of vitamin pills.
Nor is it just money that is at stake. Scientists worry that people’s health is also at risk, simply because there is a significant opportunity cost every time a patient’s care is diverted, and evidence-based medical care loses to endless formulations of oil of snake
“[Patients are] spending money and concentrating on thinking that there has to be a magic set of pills that will keep them healthy when we should all be following the evidence-based practices of eating healthy and exercising,” says Linder.
“The harm is that by talking to patients about supplements during the very limited time we have to see them, we’re missing out on advice on how to really reduce cardiovascular risks, like exercising or quitting smoking.”
New recommendations are posted on JAMAalong with an overview of the research behind the recommendations and accompanying editorial.