Americans spend about $13 billion on natural supplements a year, according to data from the National Institutes of Health. Like dietary additives, herbal supplements are known for their health and healing benefits, particularly concerning gastrointestinal issues, headaches, weight loss, menstrual pain, heart health, and even anxiety. On the surface, herbal supplements may seem like a better alternative to pharmaceuticals, given their “natural” origin—however, research shows they aren’t necessarily as safe or effective. In fact, a new study suggests that popular herbal supplements like green tea extract and turmeric can lead to liver damage.
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While dietary supplements often contain concentrated amounts of vitamins and minerals, herbal supplements are sourced from botanical compounds found in plant roots, leaves, seeds, berries, and flowers. They can be used on the skin (like aloe gel), brewed as tea, added to a hot bath (herbal salts, powders, or soaks), or digested as tablets, capsules, or liquid extracts, per John Hopkins Medicine.
Because they derive from the Earth, herbal supplements are labeled “natural” and “pure.” They’re also generally conceived by the public (especially social media) as the healthier option when compared to over-the-counter medication. But that’s not necessarily the case.
According to a study published this month in the Journal of the American Medical Association (JAMA), more than 80,000 herbal and dietary supplements (HDS) can be purchased online or at retail stores without a doctor’s note as of 2022.
Why does this matter? Well, since HDS aren’t drugs, they aren’t regulated by the U.S. Food and Drug Administration (FDA). That means companies can distribute their HDS products without prior preclinical testing and efficacy assessments, and they are free to market to the masses as they see fit. A new HDS product doesn’t need FDA approval before hitting shelves, which researchers claim is problematic.
“Chemical analyses of HDS products associated with confirmed liver toxic effects show frequent discrepancies between product labels and detected ingredients,” says the study.
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For the present study, researchers analyzed three years’ worth of data from the National Health and Nutrition Examination Survey (NHANES). Among the 9,685 adult participants, the overall prevalence of HDS use was 57.6 percent, and 4.7 percent of adults reported exposure to six “potentially hepatotoxic botanicals” that may damage the liver.
“Potentially hepatotoxic botanical products are the products that contain plant-based ingredients which have been implicated as potential causes of liver damage,” lead author Alisa Likhitsup, MD, MPH, a clinical assistant professor at the University of Michigan, told Medical News Today.
These potentially toxic herbal supplements, listed from most to least common, included turmeric, green tea, ashwagandha, Garcinia cambogia, red yeast rice, and black cohosh. More research is needed to better understand the correlation between the use of popular herbal supplements and liver damage, but Likhitsup believes metabolism could be to blame.
“How these products cause liver damage is not yet known but it is likely due to metabolism that occurs in the liver after the products were consumed,” she continued.
Again, roughly 5 percent reported use of a potentially hepatotoxic supplement within a 30-day period. However, on a broader scale, researchers noted that these statistics are “comparable with the number of people who consumed nonsteroidal anti-inflammatory drugs” in a typical calendar month as well.
“As a practicing hepatologist, I have seen patients who had liver injury from taking dietary supplements and some were fatal which required emergency liver transplant,” Likhitsup told MNT when asked about the inspiration behind the study. “We hope our results will increase awareness among patients and providers about these potentially liver toxic ingredients being consumed regularly among Americans and the dietary supplement products available in the market are not strictly regulated.”
