Six dietary supplements that claim to boost the immune system and energy can cause irreversible liver damage, according to a study.
Researchers in Michigan analyzed data from nearly 10,000 U.S. adults surveyed over a three-year period.
Participants were asked how often they took six popular but unproven dietary supplements, including turmeric, green tea extract, and ashwagandha.
The team found that the supplements, taken by one in twenty Americans, are most popular among older white women seeking to treat ailments such as arthritis, low energy and hot flashes.
As the researchers found, up to one in twenty Americans takes these supplements. The users were mainly older white women.
They warned that these common supplements may contain ingredients that could cause permanent liver damage and organ failure. However, they did not specify the amount or specific ingredients they contain. The mechanism of action is also unclear.
Dr. Alisa Likhitsup, lead study author and gastroenterologist at the University of Michigan Health, said, “Herbal and nutritional supplements (HDS) include a variety of products consumed by millions of people every day to improve their overall health and treat minor ailments.”
“Chemical analyses of HDS products that have been shown to have liver-damaging effects show frequent discrepancies between the product labels and the identified ingredients.”
The study, published Monday in JAMA Network Open, collected data from the National Health and Nutrition Examination Survey (NHANES), a survey of the general U.S. population.
The 9,685 participants were asked how often they had taken one of six dietary supplements in the past 30 days. These were turmeric, green tea extract, garcinia cambogia, black cohosh, red yeast rice and ashwagandha.
About 58 percent said they had taken at least one of these supplements in the past month. The participants who took these supplements were on average eight years older – 52 years – than the participants who did not take them.
White women were most likely to take at least one of these supplements. They were also more likely to suffer from conditions such as arthritis, thyroid disease and cancer.
Maintaining general health, preventing health problems and boosting the immune system were the most common reasons participants took the supplements. One in four who took turmeric did so for joint health or arthritis and used green tea for energy.
In addition, 70 percent of garcinia cambogia users did so to lose weight, and 84 percent of those taking black cohosh were trying to treat hot flashes. And nine out of 10 people taking red yeast rice wanted to improve their heart health.
Turmeric was the most popular supplement in the survey. It is touted for its joint benefits, although it may be linked to liver damage.
The graph above shows why users chose to take the six supplements studied
The researchers did not disclose which ingredients in these supplements could cause liver problems, but warned that the effects could be “not only serious” but could also lead to “death or a liver transplant.”
They also found that drug-induced liver damage (also called drug-induced hepatotoxicity), particularly from dietary supplements, has increased and is responsible for 20 percent of this damage.
In addition, the team cited research showing that the number of liver transplants due to damage caused by dietary supplements increased by 70 percent between 2010 and 2020 compared to 1994 to 2009.
Some studies suggest that these supplements are linked to liver problems, but most claim that these complications are rare.
For example, a 2022 study in the American Journal of Medicine found that turmeric may be linked to drug-induced liver damage, although the link is not clear.
The new study had several limitations, including not explaining the exact risk of liver damage from taking these six supplements. In addition, the ingredients in the supplements vary widely because they are not regulated by the FDA.
