A prominent consumer watchdog group is warning about potential liver risks linked to dietary supplements that contain green tea extract, including those designed for body builders, indicating that the products are increasingly associated with reports of liver damage and liver failure.
According to a Consumer Reports warning issued on May 19, dietary supplements only accounted for seven percent of drug-induced liver injuries in 2004, but that number increased to 20% by 2014.
The largest number of of those dietary supplement liver damage cases involved so-called “body building supplements”, which often include anabolic steroids. Many are also from weight loss supplements claiming to contain green tea extract.
The warning is based off of a study published in the medical journal Hepatology in November 2016, which was conducted by researchers from the Einstein Medical Center in Philadelphia. Their findings came out of a clinical research workshop by the National Institutes of Health and the American Association for the Study of Liver Disease.
The study found that in most cases, liver injuries linked to herbal and dietary supplements (HDS) involved multi-ingredient supplements, making the actual cause of liver injury hard to determine.
Researchers found that products that listed green tea extract as an ingredient were linked to 24 of the 130 cases of liver damage examined by researchers. They determined that about 10% of cases linked to green tea extract liver damage resulted in death.
Concerns over green tea extract have led to restrictions in France and Spain.
In the original study, researchers also noted that in the case of body building supplements, many linked to liver damage contained unlisted and illegal anabolic steroids. However, other ingredients have also been implicated.
The researchers highlighted a September 2013 outbreak of jaundice eventually linked to the side effects of OxyElite Pro. In Hawaii, 36 cases of acute liver injury were linked to the weight loss and body building supplement. Ultimately, more than 60 cases of liver injury were linked with the supplement nationwide.
An OxyElite Pro recall was eventually announced, and some investigators linked problems with the supplement to aegeline, an alkaloid from bael tree fruit.
Researchers criticized the current regulatory policy, which prevents the U.S. Food and Drug Administration (FDA) from regulating dietary supplements until after they have been deemed a public health risk. This problem is exacerbated by the fact that the FDA must rely on adverse event reports submitted by doctors or patients to determine if there may be a problem worth investigating, the researchers noted.
“Current regulations of dietary supplements in the United States have been criticized as being inadequate and not completely rational,” the researchers said. “Most consumers of HDS are taking the supplement on their own, without medical direction or monitoring. Adverse events may go undetected, and, if detected, are often underreported and, even if reported, often inadequately documented for reliable assessment of causality, severity, and outcome.”
The research indicates that about one-third to one-half of adults in the U.S. take dietary supplements. The industry increased from $9.6 billion in 1994 to $26.7 billion in 2014.
A study published in 2015 indicated dietary supplements are responsible for 23,000 emergency room visits every year, causing an average of 2,100 hospitalizations annually. Most of the visits involved vitamins, iron, weight loss supplants and sleep sedation products.