Avoid herbal supplements: Column

• Many believe that since these products are promoted as natural%2C and legally sold%2C that they are safe.
• But some herbal supplements can cause real health damage.
• And they are not regulated%2C as many believe%2C by the FDA.

I once diagnosed a patient with high cholesterol and prescribed medication that is commonly known as a statin. When I saw him for a follow-up months later, he admitted that he didn't fill the prescription.

He said he took red yeast rice instead. When I asked him why, he said he was wary of the long list of side effects from statins and felt that taking a "natural," over-the-counter cholesterol-fighting supplement was safer.

When it comes to taking herbal supplements, I generally inform patients that most have little evidence to suggest that they actually work, but leave the ultimate decision to patients. But two recent studies suggest that patients are better off avoiding supplements altogether.

Americans spend $5 billion a year on pills such as echinacea to ward off colds, ginkgo biloba to improve memory, or black cohosh to improve postmenopausal hot flashes. More than 29,000 herbal products are sold throughout North America, with about half of Americans using some form of alternative medicine. Many believe that because these products are promoted as natural or organic, and legally sold, that they are safe.

Not what they seem

That's not necessarily true. A study by the journal BMC Medicine, released last month, used DNA analysis to provide the most definitive evidence to date that herbal supplements are not what they seem. Researchers randomly selected 44 supplements and found most were "of poor quality, including considerable product substitution, contamination and use of fillers."

Consider two bottles of St. John's wort used to treat depression. One contained pills that had no evidence of the advertised herb, while the other substituted another plant that happened to be a known laxative.

But this goes beyond false advertising. Herbal supplements can cause real health damage. The Food and Drug Administration recently tested 21 "all-natural" dietary supplements and found that nine of them contained unlabeled amphetamine-like compounds. Unmonitored use of such stimulants can lead to elevated blood pressure, rapid heart rate and even heart attacks.

FDA issued warning

In 2012, FDA blamed the herbal industry for causing more than 50,000 adverse events annually. Some pills use fillers made up of rice, or worse, black walnut, which can severely affect people with nut allergies, while others contain unlabeled toxic ingredients. Many, including garlic and ginkgo biloba, also interact with prescription drugs, which can alter the effect of blood thinners and cause life-threatening bleeding.

Back to my patient. Like most Americans, he falsely believed that herbal supplements had to be FDA-approved before sold. And he was unaware that up to 70% of herbal drug producers violated manufacturing guidelines to prevent adulteration of their pills. I shared the recent study results with him, and he decided to stop taking the supplement.

I then addressed his concern about statins and acknowledged the potential of uncommon, and in rare cases, serious, side effects that many prescription medications share. But these drugs are regulated by the FDA, so at least we know what's inside them, and what's inside them works. That's far more than we can say about the vast majority of herbal supplements patients take today.

Kevin Pho, a primary care physician in Nashua, N.H., blogs at MedPage Today'sKevinMD.com and is a member of USA TODAY's Board of Contributors.

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