23 Apr 2025 What the science says about multivitamins, magnesium and 7 other supplements

Spoiler alert: Many claims about the benefits of supplements aren’t backed by strong data….

We get why supplements are popular: Taking a pill feels easier than addressing lifestyle factors, such as poor diet or sleep.

But in many cases, the claims behind supplements aren’t backed by strong data. And you can’t redeem an unbalanced diet by popping a pill to fill in the nutrient gaps.

As a doctor, I tend to be wary of most supplements without a medical reason. Supplements are not regulated by theFDA the way medications are, and putting anything into our bodies involves a risk-benefit calculation. While the risks of taking certain supplements are not absurdly high, don’t mistake them for zero. Run any new supplements by your physician to ensure you’re not at a higher risk of a bad outcome.

So what should you know about specific supplements? Here are nine popular ones I’ve discussed in previous columns, and what the science says about them.

Multivitamins

About one-third of Americans take multivitamins regularly. Many purchase the supplement because they think it can affect broad health outcomes — help them live longer, decrease cancer risk and reduce cardiovascular disease. Otherwise-healthy people also take it to fill gaps in their diets.

I wish it was that straightforward. Though there’s some encouraging data on the benefits of multivitamins for healthy adults, the supplement isn’t a cure-all: A study published last year in JAMA Network Open of nearly 400,000 adults who were followed for almost 30 years found that multivitamins did not confer any longevity benefit.

Taking a multivitamin daily is generally regarded as safe. But because there isn’t enough evidence of benefits for healthy adults, the U.S. Preventive Services Task Force does not recommend it.

My advice? Follow a healthy diet. This has been well established in multiple large studies to improve numerous health outcomes, from reversing coronary heart disease to reducing cancer risk.

Psyllium

Most supplements aren’t worth your money. But this one is.

Robust studies have consistently shown psyllium husk — or psyllium, for short — may lower our cholesterol, dampen glucose spikes, help us stay full longer, and even aid in treating constipation and diarrhea — all while serving our microbiome a sweet, sweet feast.

Psyllium comes from the mainly soluble fibre outer shell of the Plantago ovata plant. It’s the primary ingredient in many over-the-counter fibre supplements, but what sets psyllium apart from other fibre are two properties:

• It’s rich in arabinoxylan, a molecule that forms a gel when it contacts water, allowing psyllium to promote special reactions, including the conversion of cholesterol into bile acids, as it makes its way through the digestive tract.
• When psyllium reaches the colon, it becomes a prebiotic for your microbiome, spurring the production of beneficial metabolites such as short-chain fatty acids.

These properties result in numerous health benefits that are backed by decades of research.

Collagen

Supplementing with collagen has become increasingly popular in recent years, with brands claiming it can boost nail, skin and hair health. But there isn’t strong evidence behind these claims.

Collagen is a protein found in many parts of the body — in cartilage, bone, tendons and skin. It helps build a structural framework to preserve the skin’s integrity. But as we get old, we produce less collagen. This contributes to skin appearing less elastic — even saggy — and wrinkles forming more easily.

Though several studies on collagen supplementation point to increased elasticity and improvement in wrinkles in skin, the data is often muddied by confounding study design, lack of objective microscopic evidence or funding straight from the people selling the products.

If you want to take better care of your skin, try this science-backed routine instead….

WSJ via GetPocket.com: Read the full article here