Leafy Greens & Injured Beans: Natures Nephrotoxins – A Poison Lab & NephMadness Collaboration

The Poison Lab

In this special collaboration with NephMadness, we're diving into the world of nephrotoxins with an expert panel from Virginia Commonwealth University. NephMadness is an educational competition modeled after March Madness, and this year, one of the featured regions focuses on plant-based nephrotoxins. Together, with our expert panel we break down the competing nephrotoxin teams: Tubular Toxins vs. Oxalate Offenders.

Joining us are Dr. Anna Vinnokova (Nephrologist), Dr. Rachel Khan PharmD (Neph pharmacist), Dr. Ethan Downes (Nephrology fellow), and the legendary nephrotoxicologist, Dr. Josh King (Board certified Nephrologist and Toxicologist). We ALMOST named this episode "Getting Downe with the Mad Neph King and the Bean Queens"... but we didn't, your welcome.

After the show, go to the blog and vote for your favorite!

Expect irreverent musings, deep dives into toxic plant exposures, and a mystery case reveal that will leave you questioning your diet.

Topics and Timeline of Episode:

Intro

Listener Guesses With Josh and Ryan– 8:30

Listener Winner – 25:42

NephMadness and Guest Introductions – 28:07

Toxin Reveal – 33:41

• NEJM Case report

Tubular Toxins – 35:46

• Aristolochic Acid & the Belgian Weight-Loss Clinic Outbreak – 40:30
• Black Licorice & Its Surprising Toxic Effects – 47:16

The Oxalate Offenders Team: How Dietary Oxalates Harm the Kidneys – 52:00

• Historical Context: First recognized through sheep die-offs when herds grazed on Halogeton glomeratus, a high-oxalate plant, leading to fatal poisoning.
• Oxalate in Plants: Functions to bind excess calcium in the soil.
• Impact on the Body: Plants high in oxalate but low in calcium can contribute to oxalate accumulation, this leads to binding calcium in the blood, creating calcium oxalate crystals and acute renal calculi. Chronic inflammation from excess oxalate deposition leads to CKD progression.
• High-Oxalate Foods: Spinach, Swiss chard, rhubarb, cashews. Everything in moderation!

Practical Advice for Clinicians & Patients on Herbal Medicine Use – 1:00:00

• Resources for identifying nephrotoxic herbal products
• Talk to your patients non judgmentally, open conversations, discuss efficacy (or lack there of, see resources below) and safety
• Herbal medicines are not FDA approved and may not contain what they claim to

Herbals may not all be safe: Josh King Discovering Contaminants– 1:01:11

Wrap up– 1:08

Key Takeaways:

• Aristolochic acid is a direct nephrotoxin, associated with progressive kidney damage and urothelial cancers.
• Black licorice toxicity results from 11β-hydroxysteroid dehydrogenase inhibition, leading to excess cortisol activity, hypertension, potassium wasting, and rhabdomyolysis.
• Regulatory gaps in herbal supplements can lead to unexpected toxicities, making consumer awareness essential.
• High dietary oxalate intake increases the risk of kidney stone formation and chronic kidney disease.
• NephMadness is open to everyone—vote for your favorite nephrotoxin team and join the conversation!

Resources Mentioned:

• NephMadness: Follow along and fill out your bracket!
• AJKD Blog
• National Kidney Foundation Herbal Medicine Guide
• National Center for Complementary and Integrative Health (NCCIH)
• Poison Control Center (Available 24/7 for toxicology questions): 1-800-222-1222

Follow The Poison Lab:

• Twitter: @LabPoison
• Instagram: @tox_talk
• Website: www.ThePoisonLab.com

Don’t forget to rate and review the podcast on Apple Podcasts, Spotify, or your preferred platform. Share this episode with your fellow nephrology and toxicology enthusiasts!

Thanks for tuning in, and remember: If it sounds too good to be true, it might just be nephrotoxic. Stay safe and stay curious!