While many people are taking turmeric in concentrated supplement form, a worrying trend has emerged. In recent years, turmeric has been implicated in an increasing number of cases of acute liver injury, some of which have resulted in liver transplantation or even death.
“Turmeric-induced liver damage is considered rare — one in 10,000 or even 100,000 people who take it could get sick — but now millions of people are taking turmeric,” said Jay Hoofnagle, branch director. of Liver Disease Research in the Division of Digestive Diseases and Nutrition at the National Institutes of Health (NIH). “Based on what we see in our data, this is one of the most common causes of liver injury related to dietary supplements.”
Supplements contain more curcumin
Modern preparations based on turmeric, used in traditional medicine and as a spice in foods for thousands of years, combined with genetic susceptibility in some patients, are most likely the cause of liver damage, experts say.
The supplements contain high-dose purified extracts of curcumin, the main active ingredient in turmeric which makes up only between 1 and 7 percent of the root. Many also contain additives such as black pepper to promote the absorption of curcumin, a substance generally poorly absorbed from the digestive tract.
For example, a study that gave human subjects 2 grams of curcumin was barely able to detect it in blood samples. But after adding black pepper, the fraction of curcumin reaching the blood increased by 2,000 percent.
“Today, people are taking 100 times more curcumin than was used in traditional medicine,” Hoofnagle said. “I go to Costco and I see these big bottles of turmeric with black pepper, one gram per serving, and I’m like, ‘Oh my God.’ »
Hoofnagle oversees the Drug-Induced Liver Injury Network (DILIN), an NIH-sponsored initiative that collects and analyzes cases of serious liver injury caused by drugs and alternative medicines. In 2022, DILIN reported 10 cases of liver damage associated with turmeric supplements. The most common symptoms were jaundice, nausea and abdominal pain. Of the 10 cases, five patients were hospitalized and one patient died of acute liver failure.
The researchers concluded that liver damage from turmeric appears to be increasing in the United States and that the growing popularity of turmeric over the past five years appears to reflect the increase in case reports collected by DILIN.
Cases have also been reported elsewhere in the world. A 2020 study described seven cases of acute non-infectious hepatitis that occurred in Italy, all linked to turmeric supplements. In August 2023, the Australian government issued a safety advisory warning consumers and healthcare professionals that turmeric supplements may cause liver damage in rare cases. The advice came after the Department of Health and Aged Care received 18 reports of liver problems associated with turmeric, including one which had a fatal outcome.
“People think turmeric is naturally occurring and over-the-counter so it must be harmless, which is not true,” said Ken Liu, a transplant hepatologist at the Australian National Transplant Unit. hepatic. “As a clinician, I noticed that more and more people were being admitted to hospital with liver damage caused by herbal supplements and dietary supplements and were in need of a liver transplant. liver for that.”
Fadi Alghzawi, a resident physician at MedStar Union Memorial Hospital in Baltimore, has also noticed an increase in cases linked to turmeric. He recently saw a 66-year-old African-American woman who had been admitted to the emergency room with jaundice, nausea, decreased appetite and dark urine. Tests revealed markedly elevated levels of bilirubin in the blood – 29 mg/dL while a level of 0.2 to 1.1 mg/dL is considered normal – indicating possible liver dysfunction.
After ruling out all other causes and confirming with a liver biopsy, turmeric was found to be the culprit. Six months earlier, the patient had started taking half a teaspoon of ground turmeric as an herbal remedy from a store. Although she stopped taking turmeric as soon as she was admitted to the hospital, it was too late.
“Usually when people stop taking turmeric or any other herbal supplement that causes harm, you should see improvement,” Alghzawi said. “However, in this case, irreversible damage occurred to the liver and within seven days of admission she died.”
Drug-induced liver injury, which can be classified as direct or idiosyncratic, is the most common cause of acute liver failure in most Western countries. Direct injury is predictable, dose-dependent, and caused by agents that are intrinsically liver toxic, such as acetaminophen. In contrast, idiosyncratic injuries are much more difficult to diagnose and treat. It only affects susceptible individuals and the causative agents have little or no intrinsic toxicity.
“Idiosyncratic injury means you take a medication and then, depending on your gender, age or immune status, it can suddenly cause liver injury,” Alghzawi said. “You can’t predict it, and it’s not dose-dependent.”
For example, women are more prone to drug-induced liver injury than men due to differences in hormonal status, body composition, metabolism, and other factors. African American patients may be prone to more severe liver injury and more serious outcomes, such as liver transplantation or death, after drug-related liver injury than white patients.
Genetics are also part of the story, as certain genes code for enzymes involved in drug processing. Once ingested, a medication is absorbed through the gastrointestinal tract and absorbed into the bloodstream. The first place it goes is the liver, whose role is to eliminate toxins and metabolize medications using specific enzymes. The DILIN study found that 7 of the 10 patients carried a genetic variant, found in only 10 percent of the general U.S. population, that may have increased their susceptibility to turmeric-associated liver damage.
“These liver enzymes are dictated by genetics, so the way you metabolize something may be slightly different from the way I metabolize something,” Liu said. “You might metabolize curcumin as a completely inert and harmless metabolite, whereas I might metabolize it as something toxic and inflammatory to the liver.”
Healthcare providers and consumers should be aware of the possible risks before taking turmeric as a supplement. Alghzawi even believes that taking turmeric as a supplement should be avoided altogether, as its purported benefits do not outweigh the risks. Other experts believe in a more measured approach.
“While it is not necessary to avoid turmeric supplements completely, it is important that patients inform their doctor of their use so that follow-up can be done, if necessary,” said Angeline Liu, gastro- enterologist at Kaiser Permanente in Southern California. “Similarly, it is important for doctors to take a thorough history when speaking with patients, which includes regularly asking patients if they are taking any medications or supplements that can be purchased over the counter. »
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