Herbal and dietary supplements are more likely than medication to lead to liver transplantation or death, according to a recent study.

Researchers found that liver injury caused by herbals and dietary supplements increased from 7 to 20 percent in an American study group over a 10-year period. They suggest that liver injury caused by non-bodybuilding supplements is more severe than liver injury from bodybuilding supplements or conventional medications because it occurs more often in middle-aged women and more frequently results in death or the need for transplantation.

Nearly half of all adult Americans consume herbal and dietary supplements with prior reports suggesting that is on the rise. Medical evidence shows that supplements are used more often by women, non-Hispanic whites, those older than 40 years of age and those with more advanced education. Data from the National Health and Nutrition Examination Survey III indicate that multivitamins, minerals, calcium and fish oils are the most commonly used supplements.

"While many Americans believe supplements to be safe, government regulations (Dietary Supplement Health and Education Act of 1994) require less safety evidence to market products than what is required for conventional pharmaceuticals" Dr. Victor Navarro, lead author of the study, said in a statement. "With less stringent oversight for herbals and dietary supplements, there is greater potential for harmful consequences including life-threatening conditions."

For the study, researchers examined hepatotoxicity due to supplements compared to medications, enrolling 839 patients with liver injury between 2004 and 2013.

They determined that among cases enrolled, liver injuries from herbal and dietary supplements rose to 20 percent during the study period. While bodybuilding supplements caused prolonged jaundice (median 91 days) in young men, no fatalities or liver transplantations occurred. Death or liver transplantation occurred more frequently among cases of injury from non-bodybuilding supplements, 13 percent, than from conventional medications, 3 percent.

Researchers want their study to inform the public of potential dangers of using dietary supplements and advise that supplement producers, government agencies, healthcare providers and consumers work together to improve safety.

The findings were recently published in the journal Hepatology.