Millions of Americans Use Dietary Supplements that May be Toxic, Study Warns

Many Americans have used at least one potentially toxic dietary supplement within the past month, according to the findings of new research, which raises concerns about the lack of regulation over the industry and the adequacy of warnings provided about the potential side effects of certain ingredients.

In a study published in the Journal of the American Medical Association (JAMA) on August 5, researchers warn that many dietary supplements taken by consumers across the U.S may actually cause liver damage or disease, finding that a little over 4% of participants in a recent survey take supplements that are hepatotoxic, without recognizing the potential risks.

Hepatotoxic substances are chemicals or compounds that can cause damage to the liver. These substances can lead to liver inflammation, injury, or other forms of liver dysfunction. Hepatotoxicity can result from various sources, including herbal supplements such as turmeric/curcumin, green tea extract, ashwagandha, Garcinia cambogia, red yeast rice, and black cohosh.

Dietary supplements may contain hepatotoxic substances for several reasons, often related to the nature of the ingredients, manufacturing processes, or a failure of regulators to detect dangerous products. Many supplements contain plant extracts with naturally occurring compounds that can be toxic to the liver. High concentrations and dosages of these compounds can overwhelm the liver’s detoxification abilities, leading to toxicity.

In this new study, researchers from Baylor College of Medicine, led by Dr. Maya Balakrishnan, found that the most common reasons for using botanicals were to improve or maintain health, prevent health problems, or boost immunity. They report that many people use these products to treat or prevent specific medical conditions like osteoarthritis, fatigue, or menopause-related hot flashes. The team also noted that most users decide to take these supplements on their own, without consulting their physicians.

The researcher’s utilized data from NHANES, a national cross-sectional survey of the U.S. population, collected between January 2017 and March 2020, and incorporated population estimates from the 2020 U.S. Census for their study.

In the cohort of 9,685 adults, the average age was 47.5 years. Of these participants, 51.8% were women, 62.2% were white, 11.5% were Black, and 16.3% were of Mexican or non-Mexican Hispanic descent.

The researchers estimated that at least 15.6 million US adults used at least 1 of 6 potentially hepatotoxic botanical products within the past 30 days.

According to the findings, users of the six herbal and dietary supplements looked at by researchers were notably older, with adjusted odds ratios indicating higher use among those aged 40-59 (OR 2.36) and those 60 or older (OR 3.96). They also had higher educational levels (OR 4.78) and were more likely to have arthritis (OR 2.27) compared to non-users.

Among turmeric users, 26.8% took it for joint health or arthritis. Green tea users cited energy improvement (27.2%), while 70% of Garcinia cambogia users aimed for weight loss. Black cohosh users primarily used it for hot flashes (84.2%), and 90% of those taking red yeast rice did so for heart health.

Dietary Supplement Regulations

In the U.S., herbal and dietary supplements (HDSs) are regulated as foods and not for disease treatment. The FDA does not require verification of ingredients or safety studies unless the product contains a novel chemical. Recent studies show significant discrepancies between product labels and actual contents, and standardizing botanical products is difficult due to environmental and production variations.

The number of HDS products has increased dramatically from 4,000 in 1993 to around 80,000 by 2022, with many users relying on marketed benefits rather than professional advice. The researchers warned that it is vital for the public to be aware that most botanicals in supplements are much more concentrated than in their natural forms.

Given the limited regulatory oversight of botanical products Balakrishnan’s team recommends clinicians gather a comprehensive history of medication and HDS use when assessing patients with unexplained symptoms or liver issues. Due to the increasing popularity of these products, they urged government authorities to enhance regulation on the production, marketing, testing, and monitoring of these dietary supplements.