Lured by the allure of multivitamins and dietary supplements to fill nutritional gaps in your diet, in 2021 Americans spent nearly $50 billion (almost 48,000 million euros) is vitamins and dietary supplements.
However, scientists say that for healthy non-pregnant people, vitamins are a waste of money because there is not enough evidence that they help prevent cardiovascular disease or cancer. The new guidelines point out that there is insufficient evidence to support the use of multivitamins or dietary supplements to prevent cardiovascular disease or cancer in healthy adults.
Only pregnant women and those who are going to become pregnant still need essential vitamins (iron, folic acid), say researchers at Northwestern University in the United States, in an editorial published in the journal ‘JAMA’.
“Patients ask all the time what supplements they should take said Dr. Jeffrey Linder, chief of general internal medicine in the department of medicine at Northwestern University Feinberg School of Medicine. They waste money and focus on thinking that there has to be a series of magic pills that keep them healthy when we should all be following the evidence-based practices of eating healthy and exercising.”
Linder and other Northwestern Medicine scientists wrote the ‘JAMA’ editorial to support the new recommendations from the United States Preventive Services Task Force (USPSTF), an independent panel of national experts that typically make recommendations. evidence-based preventive clinical services.
Based on a systematic review of 84 studies, the new USPSTF guidelines state that there is not “sufficient evidence” that taking multivitamins, paired supplements, or individual supplements can help prevent cardiovascular disease and cancer in adults not pregnant otherwise healthy.
“The task force is not saying don’t take multivitamins, but there is this idea that if they were really good for you, we would already know,” Linder says.
The task force advises against taking beta-carotene supplements because of a possible increased risk of lung cancer, and advises against taking vitamin E supplements because it has no net benefit in reducing mortality, cardiovascular disease, or cancer.
“The downside is that by talking to patients about supplements for the short amount of time that we see them, we’re missing out on advice on how to really reduce cardiovascular risks, such as, exercising or quitting smoking”Linder acknowledges.
More than half of American adults take dietary supplements, and their use is expected to increase, Linder and colleagues wrote in the editorial.
Fruit and vegetable consumption is associated with decreased risk of cardiovascular disease and cancer, they say, so it stands to reason that key vitamins and minerals could be extracted from fruits and vegetables, packaged in a pill, and spared. people the trouble and expense of maintaining a balanced diet.
But, they explain, whole fruits and vegetables contain a mix of vitamins, phytochemicals, fiber and other nutrients that likely act synergistically to provide health benefits. The isolated micronutrients can act differently in the body than when naturally combined with other components of the diet.
Linder notes that people who are vitamin deficient may still benefit from taking dietary supplements, such as calcium and vitamin D, which have been shown to prevent fractures and perhaps falls in older adults.
Exception with pregnant women
The new USPSTF guidelines do not apply to those who are pregnant or trying to become pregnant, points out the co-author of the “JAMA” editorial, Dr. Natalie Cameron, an instructor of general internal medicine at Feinberg.
“Pregnant women should be aware that these guidelines do not apply to them,” explains Cameron, who is also a Northwestern Medicine physician. “Certain vitamins, such as folic acid, are essential for pregnant women to retain healthy development.” of the fetus.”
He explains that “the most common way to meet these needs is to take a prenatal vitamin. More data are needed to understand how supplementation with specific vitamins may modify the risk of adverse pregnancy outcomes and cardiovascular complications during pregnancy,” he says.