Although herbs and plants have been used for medicinal purposes for thousands of years, they have recently become very popular thanks in part to posts on the social media platform where users tout the benefits of taking herbal supplements like ashwagandha, turmeric, and green tea.
While herbal supplements may be considered “natural,” they are not inherently safe and don’t require review or approval by the U.S. FDA before going to market. Additionally, people can experience side effects with herbal supplements and certain herbs can interfere with medications they are currently taking.
Now, a new study from researchers at the University of Michigan reports that an estimated 15.6 million U.S. adults — or 5% — have taken at least one herbal supplement in the last 30 days that might be damaging to their liver, or hepatotoxic.
The study was recently published in the journal JAMA Network Open.
For this study, researchers analysed data from more than 9,500 U.S. adults with an average age of 47.5 who took part in the National Health and Nutrition Examination Survey (NHANES) years 2017 to 2020. Medical data on these participants included prescription drug and herbal supplement use.
Scientists focused on study participant use of six herbal supplements considered from past research to be potentially hepatotoxic:
1. Ashwagandha
2. Black cohosh
3. Garcinia cambogia
4. Green tea extract
5. Red yeast rice
6. Turmeric or curcumin
A clinical assistant professor in the Department of Internal Medicine in the Division of Gastroenterology and Hepatology at the University of Michigan and lead author of this study, Alisa Likhitsup, in an interview with Medical News Today, said, “Potentially hepatotoxic botanical products are the products that contain plant-based ingredients which have been implicated as potential causes of liver damage.
“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.
“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. Data from Drug Induced Liver Injury Network reported the rates of liver injury due to botanical products has been on the rise from 7% in 2004-2005 to 20% in 2013-2014. Therefore, I had (an) interest to analyze the prevalence and see how many Americans were consuming these products.”
At the study’s conclusion, Likhitsup and her team found that about 58% of all participants reported using an herbal or dietary supplement at least once within the 30-day period.
About 5% of participants said they had taken at least one of the six potentially hepatotoxic botanicals in the past 30 days. When applied to the whole U.S. population, this percentage translates to about 15.6 million adults.
This potentially hepatotoxic botanical use, researchers say, is similar to the estimated number of people prescribed potentially hepatotoxic drugs such as nonsteroidal anti-inflammatory drugs (NSAIDS) and a drug used to lower bad cholesterol levels called simvastatinTrusted Source.
“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.
“We still do not have the data about the risks of liver injury when consuming one of these products, so it will be difficult for physicians to provide this information that we do not know. And because the available dietary supplement products are not strictly regulated, each product contains multiple ingredients with more than 50% mislabeled. So, it is difficult to do research on this topic,” Likhitsup said.
Some research suggests the rates of dietary supplement mislabeling may be even higher.
After reviewing this study, Rosario Ligresti, MD, FASGE, chief of Gastroenterology at Hackensack University Medical Center in New Jersey, told MNT that while hepatotoxic botanical products are plants or plant-derived products, given a lack of regulatory oversight on the manufacturing and the lack of testing on these products, consumers need to know they may be causing their bodies more harm than good by consuming them.
“They are completely unregulated [before going to market] so my reaction is that I am not surprised that they can pose significant health risks, particularly for the liver because they are thought to interfere with the liver’s ability to process and detoxify harmful substances.
“This can lead to a buildup of toxins in the liver, which can cause inflammation, cell death, and in some severe cases, liver failure,” Ligresti said.
Ligresti noted that every physician should be talking with their patients about the risks of these types of products and asking if they are taking any of them.
“Because ‘supplements’ are supposedly made from natural ingredients, people have a false sense of security — they may believe that because the ingredients are ‘natural,’ they must be safe. However, it’s important to remember that natural does not always equal safe. Some natural ingredients can be toxic in high doses or interact with medications.
“This needs to be explained to patients along with the fact that the supplement industry is not as heavily regulated as the pharmaceutical industry. This means that companies are not required to prove the safety and effectiveness of their products before they are sold. This can lead to consumers purchasing products that are not well-studied or that may contain harmful ingredients,” he added.
