(RxWiki News) Supplements containing certain herbs, like ginseng, may be potentially harmful for people at risk for kidney disease. The herbs in question are pretty common and in wide use.
A recent study looked at a large group of people to review the types of nutritional supplements they had been taking.
The results of the study showed that many people with or at risk for kidney disease had been taking supplements containing herbs that could potentially harm their kidneys.
"Tell your doctor if you're taking any herbal supplements."
Vanessa Grubbs, MD, MPH, from the Division of Nephrology at the University of California San Francisco/San Francisco General Hospital Renal Center, led an investigation into the use of dietary supplements by people with long-term kidney disease.
Chronic, or long-term, kidney disease affects roughly 14 percent of the adult population in the US, according to the study authors.
For this study, the researchers contacted 21,169 non-pregnant adults, 20 years of age or older, in the ongoing National Health and Nutrition Examination Survey (NHANES) for an in-home interview and to collect blood and urine samples.
Participants were considered at risk for chronic kidney disease if they had diabetes, high blood pressure and/or heart disease.
Partial or full chronic kidney disease status was determined based on the amounts of albuminuria and creatinine in the urine and glomerular filtration rate, which is the amount of fluid that passes through the kidneys.
The Council in Renal Nutrition for the National Kidney Foundation has released literature and expert opinions on 37 different herbs that can appear in nutritional supplements and the impact of these herbs on the kidney health of patients with chronic kidney disease.
The study results showed that participants had been taking 5,280 distinct supplements, of which 14 percent were potentially harmful.
Of the 37 herbs that could be potentially harmful to the renal system, 18 were found among the supplements that the study subjects had been taking.
The herbs listed by the National Kidney Foundation as having negative side effects on the renal system included alfalfa, aloe, bayberry, broom, buckthorn, capsicum, cascara, dandelion, ginger, ginseng, horsetail, licorice, ma huang, nettle, noni, pokeroot, rhubarb, senna, wormwood and yohimbe.
At 37 percent, ginseng was the most commonly found herb in the potentially harmful supplements.
Next in line were ginger at 24 percent, alfalfa at 20 percent, capsicum and licorice at 15 percent, dandelion at 10 percent, aloe at 9 percent, ma huang at 7 percent, nettle at 7 percent, horsetail at 6 percent, yohimbe at 3 percent, rhubarb and cascara at 2 percent, noni and senna at 1 percent and broom, wormwood, bayberry and buckthorn at less than 1 percent.
Of the participants, 8 percent had used a potentially harmful supplement in the previous 30 days.
Overall, 9 percent of participants without kidney disease, 8 percent of participants at risk for kidney disease and 6 percent of people with at least partial kidney disease used supplements with potentially harmful herbs.
"The use of dietary supplements potentially harmful to people with chronic kidney disease is common regardless of chronic kidney disease status," the authors wrote.
The authors suggested that healthcare providers should talk about potential risks of certain harmful supplements with patients with or at risk for kidney disease.
This study was published in May in the American Journal of Kidney Diseases.
The Center for Disease Control and Prevention, the National Institutes of Diabetes and Digestive and Kidney Disease, the Robert Wood Johnson Foundation and the National Center for Research Resources provided funding for this project. No conflicts of interest were declared.