Introduction to CBD and Liver Enzymes
A new clinical trial suggests there are still ongoing questions about the safety of even low doses of cannabidiol, even as CBD capsules, gummies, edibles, oils and lotions have become increasingly omnipresent in the United States in recent years.
Scientists from the Food and Drug Administration’s Division of Applied Regulatory Science carried out a randomized double-blind placebo-controlled trial last year to assess how low-dose CBD affects liver function in a group of healthy middle-aged men and women.
The Clinical Trial
Over the course of four weeks, 201 volunteers received either 5 mg per kilogram of body weight (approximately 2.3 mg per pound or the equivalent of 350 mg for a 154-pound individual) of oral CBD, or a placebo. The goal was to give them a typical amount that might be used by consumers. Participants also underwent weekly laboratory assessments.
Results of the Trial
While the vast majority of people in the trial were unaffected, 5% showed greatly elevated levels of the liver enzyme aminotransferase, a known marker of liver cell damage or inflammation, according to the study published Monday in JAMA Internal Medicine. Women appeared to be more vulnerable than men. The liver enzyme returned to normal within one or two weeks of stopping CBD.
Seven participants withdrew from the trial because they were showing clinical signs of potential drug-induced liver injury.
Expert Opinion
“This is a significant finding, as it suggests that CBD itself, even in the absence of other drugs, may pose a risk to liver health,” says Amir Englund, a researcher at King’s College London who studies cannabinoid psychopharmacology, and was not involved in the new trial. “The results have important implications for individuals using over-the-counter CBD supplements. Many may be unaware of the potential for liver injury and assume that CBD is entirely benign.”
The Rise of CBD Products
Between 2014 and 2022, CBD product sales in the U.S. increased from $108 million to $1.9 billion, after a landmark bill passed by the Trump administration in 2018 enabled the unrestricted sale of cannabis products containing less than 0.3% THC, the psychoactive element which gets users high.
According to various surveys in recent years, the majority of people in the U.S. have now heard of CBD, and around 20% have reported using CBD products in the past 12 months.
Safety Concerns
While CBD products have become a popular way to self-medicate for conditions including pain, anxiety, insomnia and depression, especially among older adults, there’s been little evidence on how well they work or guidance on how to use the products safely.
Symptoms of Liver Injury
Identifying Liver Damage
Signs of liver injury include abdominal discomfort, jaundice or yellowing of the skin and eyes, and fatigue.
However, research has shown that drug-induced liver injuries don’t always become immediately apparent. In the FDA trial, only one of the participants with elevated liver enzymes noticed any symptoms within four weeks. The authors suggested that users may not realize that they are incurring harm and that doctors should ask about regular CBD use as part of routine medical screening.
Previous Studies
The new trial is not the first study to suggest potential health risks relating to cannabidiol and its effects on the liver. Such concerns were initially described following an FDA review of clinical trial data on CBD-based prescription drugs for childhood epilepsy, with raised liver enzymes being observed in 14% of participants.
“In clinical trials involving epilepsy patients, elevated levels of liver enzymes were among the leading causes of withdrawal from the trials due to serious adverse events,” Englund said “However, those participants were concurrently taking other anti-epileptic medications, which could have contributed to the observed liver effects.”
Mechanism of Liver Damage
Watkins was subsequently involved in research investigating why CBD can affect liver cells, and he said that certain doses seem to have an effect similar to acetaminophen, or paracetamol.
“It’s interesting because it’s also been shown that healthy adults, when they get recurrent therapeutic doses of paracetamol, also have these liver chemistry abnormalities,” Watkins said.
Conclusion
The study emphasizes the importance of monitoring liver enzyme levels in individuals using CBD products, especially those taking high doses. While the majority of participants in the trial did not experience significant liver damage, the findings suggest that even low doses of CBD may pose a risk to liver health. As the use of CBD products continues to grow, it is essential to prioritize research on their safety and efficacy.
FAQs
- What are the potential risks of using CBD products?
CBD products may pose a risk to liver health, even at low doses. Elevated liver enzymes, a marker of liver cell damage or inflammation, were observed in 5% of participants in a recent clinical trial. - What are the symptoms of liver injury?
Signs of liver injury include abdominal discomfort, jaundice or yellowing of the skin and eyes, and fatigue. However, drug-induced liver injuries may not always become immediately apparent. - How can I minimize the risk of liver damage when using CBD products?
To minimize the risk of liver damage, it is essential to follow the recommended dosage and consult with a healthcare professional before using CBD products, especially if you are taking other medications or have pre-existing liver conditions. - Are CBD products safe for everyone?
While CBD products are generally considered safe, they may not be suitable for everyone, particularly those with liver conditions or taking certain medications. It is crucial to consult with a healthcare professional before using CBD products. - What should I do if I experience symptoms of liver injury while using CBD products?
If you experience symptoms of liver injury, such as abdominal discomfort or jaundice, while using CBD products, you should seek medical attention immediately. Your healthcare professional may recommend liver function tests to assess the severity of the damage.
