Can certain herbal medications treat chronic kidney disease (CKD)? Is alternative medicine the cure for CKD?

I set off to try and answer this question after one of my patients brought along an article that claimed that "nettle leaf lowers creatinine level in the blood". This by extension would mean that it could perhaps cure CKD? I was quick to admit that not once during my typical "western medicine" training had I heard of that claim. To me, CKD had always been this inexorable malady that can be, at best, controlled or slowed down from progressing further. "Cure" is not a word that gets thrown around a lot when you talk about CKD. As I had discussed earlier, once kidney function declines chronically, it can typically not be regained.   

But I do try to have an open mind, the good old scientific temper and all that. So rather than dousing disdain over my patient's excitement, I tried to look for evidence to see if the article's claim was indeed true.
Nettle leaf (genus Urtica, a common example is the stinging nettle or Urtica dioica) is a plant widespread across Asia, Europe, Africa, and North America. I have traumatic childhood memories of being stung by its feared hair. Those hypodermic shots of formic acid and histamine! I remember the instantaneous sensation of pain that resembled a burn. It lasted a good half an hour.

What does the research show

I did a quick search on Pubmed, the database of the US National Library of Medicine. The results threw up a few basic science studies done in rats, but none in humans. Some "proof of concept" studies but no randomized trials (the highest echelon of various levels of evidence that you would depend on before the FDA will let you bring any drug in to the market). I repeated the search on Google, which took me back to the kind of articles that I had started with. All with tall claims and statements like "nettle leaf is a powerful kidney tonic", "nettle leaf has significant effects on lowering creatinine", "the supreme kidney cleanser", and my personal favorite, "when renal functions are improved, excessive creatinine will be discharged naturally by the kidneys, that is why its effects can last for long time even when patients stop taking it"! 

Really! I am aware that unfortunately, in the US, compounds like nettle leaf extract are considered dietary supplements, and thus do not come under the regulatory approval process of the FDA. So companies can essentially claim that their supplement is the fountain of youth, and back that claim with half-baked, poorly done "clinical studies"! And it'll still be legit. 

I went through the evidence in front of me. I asked myself the usual pertinent questions any physician who is appraising evidence would and should ask. How strong is the evidence? Are there any safety concerns? Was there a control group that did not get the herb in question? Would I change my practice based on the results of these trials? If creatinine really came down, does it necessarily mean that the kidney function improved, (since they are not necessarily synonymous)? Would this help patients avoid CKD Stage 5 requiring dialysis or transplantation? Would this help my patients live longer? As a nephrologist, I really could skin this cat in so many ways, and come to the same answer each time. No. Leave aside the absence of high quality randomized trials, there is no human study, period! The author of the article that set off this discussion conveniently provides no citations to support his or her claims. Another article that I came across cites the "The One Earth Herbal Sourcebook" and quotes a case report with six patients! I admit that I have not read The One Earth Herbal Sourcebook, but again...really! If any drug company wanted to treat humans with a drug which had a case study of six patients to back its claims, it would be laughed off. Besides being sued left, right, and center. It is precisely for that reason that only 0.1 percent of all chemicals tested in the lab as potential human drugs ever receive FDA approval. That is the level of strict vetting that needs to be done when you have the responsibility of safeguarding the public's health.

Is everything obtained from plants necessarily safe?

Sadly, if that substance happens to be a supplement, those rules and laws don't apply. At least not in the US. And the public at large comes under the mercy of the supplement manufacturers. Ridiculous "clinical trials" get designed with the explicit purpose of fooling the average or gullible person. "Expert opinions" of pseudo-scientists get quoted in ads. "Association" turns in to "causality". Quackery abounds. And before you can say urtica dioica, the cash registers are ringing while my patients are looking at me as the evil  representative of western medicine, or like one of my patients called it, the un-natural system of medicine! Allopathy, an often pejorative term for western medicine was coined by Samuel Hahnemann, the father of homeopathy. Ironically, the hospital where I trained in Philadelphia, a shining beacon of western medicine, is also named after him! 

Nettle leaf
Image courtesy of BrianHolm/FreeDigitalPhotos.net

What a lot of patients might not realize is that there are scores of drugs that came close to being approved for use in humans because the way they affect human physiology made sense, or because "it worked in rats". Well, rats are rats, and humans are humans. A drug called bardoxolone methyl is a recent example. It is an anti-oxidant and an anti-inflammatory agent that was shown to help kidney function and reduce creatinine levels in patients in observational studies. These were relatively better designed studies, and higher up on the scale of evidence compared to the earlier case study of nettle leaf's effect on six patients! If bardoxolone were a supplement, its manufacturer would have gone to town claiming its beneficial effects on the kidneys, and made a lot of money. That however did not happen since being a drug, its efficacy and safety had to be established further in randomized blinded studies. This was duly done. And guess what happened? That high quality final study had to be terminated early because patients who received bardoxolone experienced a higher risk of death! I shudder to think how many, harmful at worst, and worthless at best, supplements are sitting on pharmacy shelves masquerading as the next big cure for whatever. 

This is not a diatribe against any particular system of medicine. My beef is not against homeopathy or supplement manufacturers. As I said earlier, I approached this problem with an open mind. Herbs and plants have been the source of a huge number of miracle drugs; from quinine to digoxin to taxol. But, all of those drugs underwent the same rigorous scientific vetting process before they were approved for use in humans. If nettle leaf is put through a randomized blinded trial and validated, I will eat crow. But until then, please don't go around promising the moon to gullible folks. And I hope the supplement manufacturers will pick up that gauntlet since I would love to have something to offer to my kidney disease patients. If not, I hope the FDA changes its policies someday.

Skip the snake oil for now! 

This is not a unique issue with nettle leaf. Pseudoscience infests the world wide web. From websites promising to reverse CKD with guarantees (I haven't met a single nephrologist who is that awesome!), before conveniently forwarding you to a page which sells the fix for $67, to miracle cures for hypertension/heart disease/obesity...you name it. In this fog of misinformation, do I expect my patients to be as critical as I was? I would love it if they are. But, often, that is simply not true. The internet is the wild west where anything goes. And the misinformation overload can convince pretty much every lay person, save for the occasional skeptic. Couple that with a very human instinct of looking at anything derived from plants or nature as "safe", and every compound obtained synthetically from chemicals as "strong" or "unnatural/unsafe/with side effects", and one begins to understand the lure of alternative/nature medicine.  It is another matter that there are plenty of herbs out there that are obviously harmful (think monkshood, hemlock, jimson weed, etc). Finally, there often is an element of desperation...hey, I can't cure my CKD anyway, so might as well try this. Many patients fail to realize that this approach can really hurt their health. 

I told my patient to skip the nettle leaf for now. And to everyone out there I say...please shed preconceived notions, avoid bias, be critical and be skeptical before taking anyone's (including western medicine drugs!) word for it. It was this approach that took birth across Europe in the 17th century and led to modern science as we know it. Today we call it the "scientific method". If you feel overwhelmed, talk to your friendly neighborhood physician!

Veeraish Chauhan, MD, FACP, FASN
Nephrology
Sarasota, Bradenton, Florida