Podcast Summary: The Human Upgrade with Dave Asprey

Episode: These 7 Superfoods Are Secretly Wrecking Your Body (#1389)
Air Date: December 30, 2025
Host: Dave Asprey

Episode Overview

In this solo episode, Dave Asprey dives deep into the hidden dangers of high-oxalate "superfoods" like spinach, almonds, chocolate, and sweet potatoes. He unpacks why oxalates—natural compounds found in many plants and nutritional favorites—can secretly cause systemic inflammation, joint pain, metabolic issues, and even accelerate aging, despite their reputation as health foods. Drawing on historical research, personal experience, and modern biohacking science, Dave explains what oxalates do, why some people are more sensitive, how to spot if they're a problem for you, and evidence-based ways to minimize their harms while upgrading your performance and longevity.

Key Discussion Points & Insights

1. Understanding Oxalates

• What are Oxalates?
  Oxalates are compounds found in plants (especially spinach, almonds, seeds, nuts, cacao, berries, sweet potatoes, etc.) and can also be produced by your own metabolism, especially in presence of candida or fungal overgrowth.

  "They're not just anti-nutrients ... they bind directly to minerals, which means your body can't use these 'superfoods.'" (Dave Asprey, 02:38)

• Crystals & Inflammation:
  They bind minerals (mostly calcium) to form razor-sharp crystals that can accumulate in tissues, causing:

  • Inflammation, pain, and injury aggravation
  • Skin, hair, brain, and metabolic issues
  • Kidney stones (about 70% are caused by oxalate crystals)
  • Mitochondrial damage

  "They form these razor sharp calcium crystals that can cause widespread inflammation... basically sandpapering your inner organs and your knees." (Dave Asprey, 00:11)

2. Symptoms of Oxalate Overload

• Broad Range of Symptoms:

  • Joint pain, especially old injuries
  • Muscle soreness without cause
  • Skin/hair problems
  • Brain fog, fatigue
  • Kidney stones, urinary tract irritation ("burning pee")
  • Scars and surgical areas flaring up
  • Pelvic pain, unusual plaque on teeth, styes in eyes
  • Brain/nervous system issues (neuropathic pain)

• Systemic and Subtle:
  Problems may develop slowly and accumulate, acting more like a slow heavy metal poisoning than a food allergy.

• Biofeedback Tip:
  Eat a high-oxalate meal and observe if old injuries or joints suddenly hurt more, or if symptoms flare up.

  "All of a sudden that joint that hasn't bothered you does ... there's a pretty good chance you just showed yourself what's going on." (Dave Asprey, 11:12)

3. Why Does Oxalate Tolerance Vary?

• Factors:

  • Genetics: Differences in SLC26A6, AGXT genes, etc.
  • Gut Health: Presence of oxalate-degrading bacteria (rare now, per Dave)
  • Mineral status, hydration, urinary/systemic pH
  • Candida Overgrowth: Fungal issues can increase oxalate production and leaky gut.
  • Age: Tolerance decreases as kidney function and mineral reserves drop with aging.
  • Hormones: Vitamin D & parathyroid hormone control calcium distribution, K2 keeps calcium in the bones.

• Dumping Syndrome:
  If you go from eating lots of oxalate to suddenly none, stored tissue oxalate is rapidly released ("oxalate dumping"), which can worsen symptoms temporarily before improving.

  "I stopped eating oxalate, but I felt worse. That's because your body's trying to excrete it when it finally gets a chance." (Dave Asprey, 09:37)

4. The Dangers Hiding in Superfoods

• High-Oxalate Offenders:

  • Spinach, beet greens, Swiss chard
  • Almonds, cashews, peanuts (and anything with almond flour)
  • Cocoa/cacao/dark chocolate
  • Potatoes, sweet potatoes (especially skins)
  • Black tea, matcha, green tea (in high amounts)
  • Raspberries, blackberries, buckwheat, cassava flour

• Hidden Effects:

  • Chelates/binds to beneficial minerals (magnesium, iron, calcium), decreasing energy and recovery.
  • Causes vascular issues, stiffens fascia/collagen (accelerated aging via tissue fibrosis).
  • Promotes histamine release—worse in those with sensitivities (e.g., mast cell activation, long Covid, toxic mold, etc.)

  "It's going to release an inflammatory cytokine called IL1B and something called the NLRP3 inflammasome... It also causes tissue fibrosis via those pathways." (Dave Asprey, 18:32)

5. Practical Strategies for Oxalate Management

a) Low-Oxalate Food Swaps

• Replace spinach with arugula, romaine, or lettuce.
• Swap almond or cassava flour for rice or coconut flour (note: buckwheat/cassava also high).
• Choose white rice over brown.
• Limit cocoa/chocolate to special treats ("CocoaVia" mentioned as a lower-oxalate option).
• Dairy (if tolerated) or small fish with bones (sardines) can help provide calcium.

b) Meal Tactics

• Add calcium (preferably as calcium citrate) with high-oxalate meals to bind oxalate in the gut and reduce absorption.
• Take magnesium later in the day.
• Support hydration (especially after exercise or sauna use); dehydration worsens symptoms.
• Use lemon juice or potassium citrate to help prevent oxalate crystal formation—citrate blocks crystals.
• Avoid juicing high-oxalate greens; it concentrates oxalates.

"If you eat a high oxalate meal, take calcium citrate during the meal... and you can use lemon water or potassium citrate, which will raise urinary citrate and block the crystal formation." (Dave Asprey, 28:31)

c) Lifestyle & Monitoring

• Check urine pH (with strips); use baking soda to adjust if needed.
• Taper oxalate reduction to avoid severe dumping symptoms.
• High-sweat activities (endurance sports, sauna) can worsen mineral losses—rehydrate and mineralize well.

6. Who Should Pay Attention?

• People with:
  • Recurrent urinary tract infections or kidney stones
  • Unexplained inflammation, fatigue, pain, or histamine/mast cell sensitivities
  • History of toxic mold, Lyme, long Covid, or gut issues
  • Sudden worsening after adding certain "healthy" foods back into the diet (especially after keto/carnivore phases)

7. Notable Quotes/Memorable Moments

• “Drinking a 32 ounce green smoothie with spinach and beets and almond milk every day for 10 days, by the way, that did kill one person.” (Dave Asprey, 00:50 & 23:13)
• “Oxalates behave more like a slow accumulation problem, almost a toxic heavy metal than an acute toxin.” (Dave Asprey, 23:20)
• “Most doctors know that oxalate can cause kidney stones, and that's about it. But the primary target ... is your urinary tract and your kidneys. The other areas where you're likely to feel oxalates are your joints, your skin, your pelvic tissues...” (Dave Asprey, 19:48)
• “The goal isn't eliminating them all, it's being aware of them and getting your total oxalate intake to under 200 milligrams per day for the average person.” (Dave Asprey, 35:44)

Timestamps for Important Segments

| Time | Segment/Topic | |-----------|-------------------------------------------------------------------| | 00:00 | Introduction to oxalates and their hidden dangers | | 04:00 | How oxalates work; symptoms and storage in the body | | 07:40 | Oxalate metabolism, candida link, and historical research | | 12:00 | How to identify oxalate issues; impact on injuries and scars | | 15:50 | Hormones (Vitamin D/K2/parathyroid) & oxalate metabolism | | 18:32 | Inflammatory pathways, accelerated aging, tissue fibrosis | | 21:50 | Genetics, gut bacteria, and summary of risk factors | | 23:20 | Oxalate's slow accumulation and aging, young vs. older tolerance | | 25:43 | Symptoms in biohackers, special risk populations | | 26:58 | High oxalate foods to minimize or avoid | | 28:25 | Food swaps and supplementation strategies (calcium, magnesium) | | 30:00 | Hydration, exercise, and sweat—why endurance athletes should care | | 32:47 | Testing, symptoms tracking, safe reduction, awareness | | 36:55 | Closing summary and key takeaways |

Conclusion & Takeaways

Dave Asprey urges listeners not to fear plants or fall for food dogmas blindly, but to understand that some "superfoods" may be silently undermining health through their oxalate content. He encourages individualized testing and awareness—not total avoidance—suggesting simple swaps, timing, and supplementation can make a huge difference to joint pain, energy, aging, and overall performance.

If you’ve been mystified by unexplained aches, recurrent kidney stones, or declining energy—especially despite a “clean” diet—this episode uncovers the counterintuitive biochemical reasons why, and arms you with practical steps to identify and minimize oxalate trouble.

Not sure if oxalates are a problem?
Try eliminating high-oxalate foods (gradually), monitor your symptoms, and use Dave’s biohacking tactics to reclaim your energy and performance.

References:

• Sally K. Norton, Toxic Superfoods (for further oxalate info)
• The Bulletproof Diet (Dave Asprey’s core nutrition book)

Final Message:

“It's not that you should avoid all oxalate foods forever ... The goal isn't eliminating them all, it's being aware of them and getting your total oxalate intake to under 200 milligrams per day for the average person.” (Dave Asprey, 35:44)