Most patients ‘wasting money’ on vitamin supplements to avoid heart disease, cancer

After years of study and growth of a multibillion-dollar industry, there’s still no conclusive proof vitamin supplements are helping patients dodge heart disease and cancer.

The U.S. Preventive Services Task Force (USPSTF), an independent panel of national experts, updated its recommendation about the effectiveness of multivitamins to prevent cardiovascular disease and cancer in healthy, nonpregnant adults.

The result: insufficient evidence, according to the recommendation statement, an evidence report and two editorials all published June 21 in JAMA. The Northwestern University Feinberg School of Medicine also published a news release about the findings.

What works better? A healthy diet and exercise.

“Patients ask all the time, ‘What supplements should I be taking?’ They’re wasting money and focus thinking 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,” Jeffrey A. Linder, MD, MPH, FACP, chief of general internal medicine in the department of medicine at Northwestern University Feinberg School of Medicine, said in the news release.

Vitamins everywhere

More than half of American adults take dietary supplements to improve or maintain overall health. In 2021, Americans spent almost $50 billion on dietary supplements, an industry that spent about $900 million on marketing, Linder and coauthors Jenny Jia, MD, MSc, and Natalie Cameron, MD, said in the editorial.

“The appeal of supplements is obvious,” the editorial said. “In theory, vitamins and minerals have antioxidative and anti-inflammatory effects that should decrease the development of cardiovascular disease and cancer. Eating fruits and vegetables is associated with decreased cardiovascular disease and cancer risk. It is reasonable to think 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.”

However, whole fruits and vegetables contain a mixture of vitamins, phytochemicals, fiber, and other nutrients that probably act synergistically to deliver health benefits. Micronutrients in isolation may act differently in the body than when packaged naturally with other dietary components, the authors said.

The supplements “are relatively unregulated” and must have disclaimers that they have “not been evaluated by the Food and Drug Administration” and they are “not intended to diagnose, treat, cure, or prevent any disease,” the editorial said.

Healthy lifestyle needed

Most people view supplements as benign preventive products, but focusing on supplements may be a potentially harmful distraction, the authors said.

Healthy eating can be a challenge when the U.S. industrialized food system does not prioritize health, said Jia, an instructor of general internal medicine and a Northwestern Medicine physician who studies the prevention of chronic diseases in low-income families through lifestyle interventions.

“To adopt a healthy diet and exercise more, that’s easier said than done, especially among lower-income Americans,” Jia said in the news release. “Healthy food is expensive, and people don’t always have the means to find environments to exercise — maybe it’s unsafe outdoors or they can’t afford a facility. So, what can we do to try to make it easier and help support healthier decisions?

Recommendations

The latest recommendations update the 2014 guidance and are based on a review of 84 studies since then.

USPSTF recommended:

• Against taking beta-carotene supplements because of a possible increased risk of lung cancer
• Against taking vitamin E supplements because it has no net benefit in reducing mortality, cardiovascular disease or cancer

The findings do not apply to adults with known nutritional deficiencies, and Linder noted calcium and vitamin D have been shown to prevent fractures and maybe falls in older adults.

Helping pregnancies

Patients pregnant or trying to be should take supplements of folic acid and iron for health effects.

“Pregnant individuals should keep in mind that these guidelines don’t apply to them,” Cameron, a Northwestern Medicine physician, said in the news release. “Certain vitamins, such as folic acid, are essential for pregnant women to support healthy fetal development. The most common way to meet these needs is to take a prenatal vitamin. More data is needed to understand how specific vitamin supplementation may modify risk of adverse pregnancy outcomes and cardiovascular complications during pregnancy.”