Attracted by the lure of multivitamins and dietary supplements to fill nutritional gaps in their diets, by 2021. Americans will spend nearly $50 billion (nearly 48 billion euros) on vitamins and food supplements.
However, scientists say that for healthy, non-pregnant people, vitamins are a money loss 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 will become pregnant still need essential vitamins (iron, folic acid), say researchers from Northwestern University in the United States in an editorial published in the journal “JAMA”.
“Patients ask all the time what supplements they should take. –According to Jeffrey Linder, MD, chief of general internal medicine in the department of medicine at Northwestern University’s Feinberg School of Medicine. They waste money and focus on the idea that there must be a magic pill to stay healthy, when we should all be following evidence-based practices of eating healthy and exercising .
Linder and other Northwestern Medicine scientists wrote the “JAMA” editorial to support new recommendations from the US Preventive Services Task Force (USPSTF), an independent panel of national experts that typically makes recommendations based on evidence for clinical prevention services.
Lack of evidence
Based on a systematic review of 84 studies, the new USPSTF guidelines indicate that. there is no “sufficient evidence” that taking multivitamins, combination supplements or individual supplements may help prevent cardiovascular disease and heart disease. cancer in adults otherwise healthy and not pregnant.
“The task force isn’t saying you shouldn’t take multivitamins, but the idea is that if they were really good for you, you would know it by now,” Linder says.
The task force specifically advises against taking beta-carotene supplements due to a possible increased risk of lung cancer, and taking vitamin E supplements because it has no clear benefit in terms of reducing mortality, cardiovascular disease or cancer.
“The unfortunate thing is that by talking to patients about dietary supplements in the short time we see them, we miss advice on how to actually reduce cardiovascular risk, for example, exercise or stop smoking”.Linder recognizes this.
Consumption on the rise
More than half of American adults take dietary supplements, and their use is expected to increase, Linder and his colleagues wrote in the editorial.
Fruit and vegetable consumption is associated with a lower risk of cardiovascular disease and cancer, they note. So it only makes sense that essential vitamins and minerals could be extracted from fruits and vegetables, packaged in pill form, and save people the hassle 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 are likely to work synergistically to provide health benefits. The website Isolated micronutrients may act differently. in the body only when naturally combined with other components of the diet.
Ms Linder points out that people who are deficient in the vitamins can still benefit from taking dietary supplements, such as calcium and vitamin D, which have been shown to prevent fractures and possibly falls. in the elderly.
Exception for pregnant women
The new USPSTF guidelines do not apply to women who are pregnant or trying to become pregnant, points out the co-author of the “JAMA” editorial, Dr. Natalie Cameron, an instructor in general internal medicine at Feinberg.
Pregnant women should be aware that these guidelines do not apply to them,” says Cameron, who is also a physician at Northwestern Medicine. Certain vitamins, such as folic acid, are essential for pregnant women to help the healthy development of the fetus.
He explains that “the most common way to meet these needs is to take a prenatal vitamin. Further data are needed to understand how supplementation with specific vitamins may alter the risk of adverse pregnancy outcome and cardiovascular complications during pregnancy,” he notes.