Kidney Disease and Supplements: Herbs, Minerals and Protein Products

Aristolochic acid is the clearest documented kidney danger from herbal products. A review of the evidence describes Belgian women who took slimming pills containing a Chinese herb and went on to develop kidney failure and cancer of the upper urinary tract. [1] Health Canada advised consumers in 2004 not to use products containing it, calling it a naturally occurring toxin that can cause cancer, mutations in human cells, and end-stage kidney failure. [2] If you have used such a product, ask a kidney doctor or your regular clinician about follow-up. If someone has very little urine, severe swelling, confusion or trouble breathing, call 911.

Why kidneys need extra care

Some herbal supplements leave the body through the kidneys, so the body can reach toxic levels when the kidneys do not work well, and the label may not say so. [3] The National Kidney Foundation (NKF, US) says supplements can make kidney disease worse, interact with prescription medicines, or raise the risk of complications. [3] For people with a kidney transplant, it adds that an interaction can increase the risk of losing the new kidney. [3] NKF also notes that studies of herbal products often do not include people living with kidney disease, which makes good information hard to find. [3] MedlinePlus lists diabetes and high blood pressure as raising kidney disease risk, and medicines as one possible cause of kidney damage. [4]

Aristolochic acid: tradition and research, kept apart

Traditional use. Plants in the Aristolochia genus and related plants such as Asarum have been used in Chinese herbal practice; the review above lists many conditions for which herbs containing the acid were prescribed. [1]

Research and regulators. The review concludes that herbal remedies containing aristolochic acid have been designated a strong carcinogen, and recommends banning such use and educating health professionals and the public. [1] Another review says more than 100 kinds of herbal medicine are reported to cause kidney toxicity, and that other components besides aristolochic acid are involved. [5] NKF says aristolochic acid is banned in many countries but still present in some traditional remedies. [3] The ingredient comes from plants of the Aristolochia, Bragantia and Asarum genera. [1] GBIF lists Aristolochia fangchi, a name used in older papers, as a synonym of Isotrema fangchi. [6] Health Canada warned in 2004 that some herbal products could contain Aristolochia and its toxic aristolochic acid by mistake. [2] Mislabeling is part of the problem; do not try to identify these plants yourself. Ask a pharmacist or the practitioner, and see adulteration and mislabeling and banned and restricted ingredients.

Herbs and products NKF flags for kidney disease

NKF gives examples with a high level of risk for people with kidney disease, especially kidney failure, dialysis or transplant, and says the list is not comprehensive. Examples include Aristolochia products, licorice root (Glycyrrhiza glabra), horsetail (Equisetum arvense), St. John's wort and creatine, which NKF notes is not an herb but is often sold as a supplement. [3] The risk depends on product quality, how long it is used, the reason, other conditions and other medicines. [3]

Minerals, protein and creatine

For minerals, see minerals, supplements and kidney disease and the potassium page. NIDDK says some people with chronic kidney disease may need moderate protein so waste does not build up, but too little protein can cause malnutrition, so a dietitian or clinician should help find the balance. [9] Proper evidence not found in the NIDDK and NKF pages we read about protein powders or amino acid products specifically, so we cannot say how they affect kidneys; see protein powder safety and creatine, kidney questions and creatinine testing.

Ask before adding anything

Show your kidney team the exact label, including combination products. NKF recommends avoiding "proprietary blends" because they may hide amounts of each ingredient. [3] Use the talking with a health professional guide, and return to Existing Health Conditions.

What we could not read

Australia's TGA has an Aristolochia alert for practitioners, but the page timed out for us, so we do not quote it. We also could not read NIH's ODS pages.