Herbal supplements: Health or hype?

Herbal supplements may seem like a natural health remedy, perfect for treating a range of chronic conditions, including fatigue, anxiety, dementia and depression.

But can these plant-based products reduce your risk for cancer?

“Much of the evidence is quite questionable,” says Lorenzo Cohen, Ph.D., professor and director of Integrative Medicine at MD Anderson. So, you should approach herbal supplements with caution and speak with your doctor before taking any, whether you’re considering a pill, capsule, tablet or liquid form.

Our experts share what you need to know about the health effects of herbal supplements.

Natural doesn’t mean safe

Just because a product comes from Mother Nature doesn’t necessarily make it safe to use.

The Food and Drug Administration regulates herbal supplements as foods. This means they don’t have to meet the same standards as drugs or over-the-counter medications for proof of safety and effectiveness. Companies also don’t have to follow the FDA’s Good Manufacturing Practices.

“Without government oversight on the product manufacturing and development, a bottle of pills can be contaminated or have more or less of the herb than it’s advertising,” Cohen says. 

Holly Holmes, M.D., associate professor in General Internal Medicine at MD Anderson, advises that you always think of herbal supplements as drugs. “This means they need to be given the kind of concern you’d give anything you’re using for the first time.”

Supplements may do more harm than good

Some herbal supplements have claimed to benefit cancer patients, reduce cancer-related symptoms or alleviate treatment side effects.

Some studies indicate soy, a plant protein loaded with fiber, potassium and magnesium, may decrease breast and prostate cancer risks. It may also improve treatment success for these cancers. Producers of supplements containing ginseng claim it fights fatigue and weakness, and producers of supplements with ginger claim it curbs nausea, all common cancer side effects.

“More research is needed to prove these supplements have the health benefits they advertise before they can be clinically prescribed,” Cohen said. Some herbal supplements have even shown to harm users’ health.

Ginkgo, the most popular herb on the market, is used to prevent dementia and improve memory, but it increases bleeding risk. St. John’s Wort, shown to be effective in treating mild to moderate depression, can interfere with metabolism of other drugs.  

If you’re taking medications or receiving cancer treatment, you need to be especially cautious. Most herbal supplements are thought to have negative interactions with chemotherapy drugs.

“Even an antioxidant such as green tea can be harmful when consumed as a supplement instead of a beverage if you’re undergoing cancer treatment or are a cancer survivor on medications,” says Katie Bispeck, research dietitian in Behavior Science at MD Anderson. “Don’t assume anything is safe.”

Ingest herbs in their natural state

If you want to try herbal remedies, it’s best to ingest them from their natural state and with your doctor’s permission.

Instead of taking green tea capsules, brew a cup of green tea. You can also cook and flavor your meals with fresh herbs, in place of popping a pill. Just be mindful of the amount you ingest.

Talk to your doctor or dietitian

Before taking any herbal supplements, speak with your doctor or a registered dietitian. He or she can help you decide whether a supplement is right for you and the dose you should take.

A registered dietitian also can tell you what to look for on supplement labels. This is important because some supplement labels can be confusing or misleading. In addition, dietitians can help you find whole foods to replace herbal supplements.

“It’s great that people want to take an active role in their health,” Holmes says. “But do your research and talk to your doctor. What you put in your body should be taken seriously.”

Request an appointment at MD Anderson's Lyda Hill Cancer Prevention Center online or call 877-632-6789.