When it comes to what you put in your body, few phrases are as questionable as “it’s natural.” Plants like oleander, water hemlock, and, most obviously, deadly nightshade are all lethal if consumed. So are tobacco leaves and even apple seeds. Assuming that an herbal supplement is safe just because “it’s natural” is a mistake. Even supplements that are okay for most people can harm those with kidney disease. Before you use any herbal supplements, here’s what you need to know about herbal supplements and kidney disease.
Hardworking Kidneys
Acting as your body’s filtration system, your kidneys remove impurities from the blood. This pair of organs sits below your rib cage with one on either side of your spine. About the size of a fist and the shape of a bean, they help keep your nerves, muscles, and other tissues healthy. They also regulate blood pressure and produce red blood cells. Unfortunately, the early stage of kidney disease is often asymptomatic––which means you could be the one out of three adults at risk for kidney disease without even knowing it. That’s why taking a supplement that could harm the organ is so risky.
In the United States, herbal supplements are regulated by the Food and Drug Administration (FDA) as a food–not as a drug. The FDA doesn’t examine dose, content, or purity of supplements. They often have ingredients not listed on the label such as aristolochic acid which can harm the kidneys. Others behave as a diuretic and, by increasing your urination, can also harm the kidneys. Worse, if you order a supplement online and it arrives from another country, it could be loaded with heavy metals or other toxic substances. Finally, those in later stages of kidney disease must avoid foods that are bad for kidneys and some supplements containing the same kidney-damaging substances.
Supplements to Avoid
An earlier study examined the potential kidney damage from a number of popular substances. Some, like creatine and the now-banned supplement ephedra, were often used by athletes. At high doses, they could damage healthy kidneys. In fact, taking more than the recommended dose of any supplement is a bad idea. While vitamin C supplements are generally considered safe, consumption of more than the recommended daily allowance has been linked to kidney stones. Although earlier studies showed that patients with both diabetes and advanced kidney disease doubled their risks of heart attack or strokes when they took high doses of folate, B6, and B12, a recent study showed some health benefits for patients taking folic acid and B12. It also was beneficial for recent transplant recipients.
Just as patients with later-stage kidney disease have to avoid food with phosphorus like oatmeal, beans, and dark-colored sodas, they should also avoid supplements like American ginseng and turmeric. Potassium-laden foods like oranges and bananas should be avoided along with mugwort and kelp supplements. Some supplements can interfere with your medications, including St. John’s wort and echinacea.
Just as supplements have higher risk factors for patients with kidney disease, over-the-counter drugs are also risky. Non-steroidal anti-inflammatory drugs like aspirin, ibuprofen, and naproxen are all potentially damaging to your kidneys. As with vitamins, just because they are easily obtained it does not mean they should be downed like jelly beans. Taking high doses of any over-the-counter medication, especially for weeks or months, can lead to kidney damage. High doses can also harm your liver and stomach.
The bottom line is to always consult with your healthcare provider before taking any herbal supplement. It may be natural, but that doesn’t mean it’s safe.
Written by John Bankston
