Potentially Hepatotoxic Supplements are Widespread
Products containing potentially hepatotoxic botanical ingredients are being widely consumed in the US, according to a study from University of Michigan researchers. The study, which was published in JAMA, examined national survey data from 2017–2020 and found that over a 30-day period, 4.7% of the adults surveyed 2020 took herbal and dietary supplements containing at least one of the hepatotoxic botanicals selected for the study.
Over 80 000 herbal and dietary supplement (HDS) products are available for purchase without a prescription for the purposes of promoting general health and treating minor ailments, and are largely unregulated. Most of these are products such as multivitamins, with well-defined ingredients on the label. But an estimated 5% to 12% of HDS products are plant-derived, complex multi-ingredient botanicals, some of which have been shown to have hepatotoxic properties. These included products containing turmeric, green tea, ashwagandha, black cohosh, garcinia cambogia, and red yeast rice.
Lead author Alisa Likhitsup, MD, MPH, clinical assistant professor of Medicine at U-M spoke about the motivation for the study. “Our interest started when we saw cases of liver toxicity from herbal and dietary supplement use in people enrolled into the ongoing NIH-funded DILIN study,” Likhitsup said.
“But it was difficult to say how many people were using these supplements and why. The major finding here is the large number of Americans taking these products with an estimated 15 million adult Americans taking them on a regular basis.”
Supplements are of particular concern for the researchers for several interrelated reasons: lack of government regulation, insufficient attention in medical screenings, and frequent mislabelling.
“In a previous study, we found that there was a great deal of mislabelling of some of these products,” said senior author Robert Fontana MD, U-Me hepatologist, professor of medicine.
“We performed analytical chemistry and found about a 50% mismatch between stated ingredients on the label and what they actually contained, which is quite alarming. If you buy a supplement and it says it has a certain ingredient, it’s basically a coin flip if that’s true or not.”
The mislabelling comes about from a lack of regulation, and since the effects are poorly understood, patients are not often asked what supplements they are taking.
Another study had found a 70% increase in liver transplants due to injury caused by supplements from 2010–2020, compared to 1994–2009.
“We weren’t aware that so many people were taking these supplements,” said Likhitsup, a transplant hepatologist.
“So, when doctors see patients in the office, they don’t necessarily ask about supplement use or take into consideration their effects.”
In the studied population, the highest proportion of people consumed turmeric (3.46%), followed by green tea (1.01%), ashwagandha and black cohosh (0.38%), garcinia cambogia (0.27%), and red yeast rice products (0.19%). Most of the users did not start consuming the botanicals on doctor’s advice, instead it was their own accord. They most commonly cited reason was the improvement or maintenance of health.
Of the turmeric users, 26.8% consumed the products specifically for supposed benefits for joint health or arthritis, while 27.2% of the green tea users were hoping to improve their energy levels.
The majority of the garcinia cambogia users hoped it would help them lose weight.
The JAMA study was not able to establish any kind of causal relationship between consumption of the six botanicals and liver injury since it was intended to assess supplement exposure in the general US population. Given the lack of regulation, however, the researchers still hope to make clinicians and patients aware of just how much is still unknown about these supplements.
“We’re not trying to create alarm,” Fontana said.
“We’re just trying to increase awareness that the over-the-counter supplements people are taking and buying have not been tested nor necessarily proven to be safe.”
