Oxalate Concerns, Essential Oils for the Gut and Thyroid

Welcome to Healthy Gut Healthy Thyroid!

This is your weekly roundup of the BEST actionable steps for those people with thyroid and autoimmune thyroid conditions who want to restore their health…by healing their gut. Whether you have hyperthyroidism or Hashimoto’s you will benefit from the content in this newsletter.

In today's issue:

• Main Topic: The Impact of Oxalates on the Gut and Thyroid

• Podcast Review: How Can Estrogen Dominance Be Addressed?

• Understand Your Tests: Understanding Oxalates

• Ask Dr. Eric: Which Essential Oils Can Benefit the Gut and Thyroid?

The Impact of Oxalates on the Gut

Oxalates are naturally occurring molecules found in many plant foods. While they serve certain functions in plants, in humans, oxalates can bind to minerals like calcium and form crystals. These crystals can deposit in various areas of the body, including the bones, blood vessels, central and peripheral nervous systems, retina, skin, and even the thyroid gland.

Although most thyroid conditions aren’t directly caused by oxalate buildup, oxalate accumulation in the thyroid may impair its function and contribute to symptoms like fatigue, inflammation, and metabolic disruption. For those with thyroid or gut issues, especially if symptoms persist despite other interventions, evaluating oxalate levels can be worthwhile.

Three Primary Causes of Elevated Oxalate Levels

A Diet Rich in Oxalates. Certain foods are naturally high in oxalates. Regular, excessive intake can lead to accumulation, especially in people with gut or metabolic issues. For example, I used to add large amounts of spinach to my daily smoothies.

Now, I still enjoy smoothies but use lower-oxalate leafy greens like arugula and collard greens and limit high-oxalate foods like beets and nuts to avoid overloading my system.

Yeast and Fungal Overgrowth. Yeasts like Candida and molds like Aspergillus can produce oxalic acid as part of their metabolism. Individuals dealing with intestinal yeast or mold overgrowth may experience elevated oxalate levels as a result.

Addressing the overgrowth with antifungal herbs or medications can help lower oxalate burden. Environmental or dietary mold exposure can also contribute.

Impaired Oxalate Metabolism. Some individuals have a genetic tendency to accumulate oxalates due to enzyme deficiencies that affect oxalate processing. Functional testing, such as the Organic Acids Test (OAT) from Mosaic Diagnostics, can identify patterns of dysregulated oxalate metabolism.

The OAT measures:

✔Oxalic acid (often elevated from diet or yeast overgrowth)

✔Glycolic acid (elevations may indicate primary hyperoxaluria type 1)

✔Glyceric acid (elevations may indicate primary hyperoxaluria type 2)

Understanding which metabolites are elevated can guide dietary, supplemental, and lifestyle strategies.

Common Symptoms of High Oxalates

Not everyone with elevated oxalate levels will develop symptoms, but some may experience:

➡ Joint or muscle pain (from crystal deposition in connective tissues)

➡ Kidney stones (calcium oxalate stones)

➡ Digestive symptoms (bloating, cramping, loose stools)

➡ Burning or irritation in the eyes or skin

➡ Nerve pain or tingling (peripheral neuropathy)

➡ Chronic fatigue or brain fog

➡ Painful urination or urinary urgency

Foods High in Oxalates (From my book The Hyperthyroid Healing Diet):

• Spinach

• Swiss chard

• Nuts (especially almonds and cashews)

• Soy

• Peanuts

• Beets

• Sweet potatoes

• Chia seeds

• Collagen (contains hydroxyproline, which the body can convert into oxalate)

How Oxalates Affect the Gut

On the Save My Thyroid podcast, I interviewed Sally K. Norton, author of Toxic Superfoods, who discussed how oxalates can damage the intestinal barrier and contribute to leaky gut syndrome.

Oxalate crystals can:

✔Pierce and irritate the intestinal lining, causing microtrauma to gut tissue

✔Trigger inflammation, increasing the release of immune signaling molecules like cytokines

✔Bind to beneficial minerals, reducing nutrient availability for the gut lining

Over time, this damage can worsen intestinal permeability, allowing undigested food particles and toxins into the bloodstream, which may fuel autoimmunity, including Hashimoto’s or Graves’ disease.

How to Lower Oxalate Levels

Managing oxalates involves a stepwise and gradual approach, since reducing oxalates too quickly can mobilize crystal deposits and worsen symptoms. Key strategies include:

✅ Gradually reduce high-oxalate foods

✅ Rotate or limit foods like spinach, almonds, beets, and chocolate instead of cutting them all at once.

✅ Replace with low-oxalate vegetables (e.g., arugula, lettuce, bok choy).

Support Gut and Microbial Health

✅ Address fungal overgrowth with herbs (oregano, berberine, caprylic acid) or medications.

✅ Incorporate probiotics, particularly species like Lactobacillus plantarum, which help break down oxalates. I'm hoping in the future they'll also have a Oxalobacter formigenes probiotic supplement, as this also can break down oxalates.

Ensure Nutrient Sufficiency

✅ Calcium citrate binds oxalates in the gut, reducing absorption.

✅ Magnesium citrate and potassium citrate can help prevent crystal formation.

✅ Vitamin B6 supports oxalate metabolism.

Hydration and Detoxification Support

✅ Drinking plenty of filtered water helps flush oxalates through the kidneys.

✅ Supporting liver detoxification (with foods like cruciferous vegetables) aids processing.

Retest if Necessary

Follow-up with an Organic Acids Test to track progress, especially if symptoms persist.

Conclusion

Oxalates can quietly contribute to gut irritation, nutrient depletion, and even thyroid dysfunction—often going undetected. While not the root cause for most thyroid conditions, addressing elevated oxalates can reduce inflammation, protect the gut lining, and improve overall metabolic balance.

By identifying the source of high oxalates—whether diet, microbial overgrowth, or metabolic dysfunction—and using a gradual, supportive approach to lower them, individuals can protect both their gut and thyroid health.

Find Your Hashimoto’s Triggers

If you have Hashimoto’s thyroiditis, visiting an endocrinologist is likely to result in a prescription for thyroid hormone replacement. And while there is a time and place for thyroid hormone, the problem is that it doesn’t do anything for the autoimmune component of Hashimoto’s.

And so what happens is that many people will take thyroid hormone without doing anything to improve the health of their immune system, which means that over time further damage to their thyroid gland will take place.

The good news is that you can do things to reverse the autoimmune component of Hashimoto’s. And the best way to accomplish this is by finding and removing your triggers.

My book “Hashimoto’s Triggers” will show you how to do this. By reading this book you will discover the following:

• More than one dozen triggers of Hashimoto’s thyroiditis

• The different diet options, and how to detect your specific food triggers

• Everything you need to know to heal your gut

• How to reduce fatigue, brain fog, hair loss, lose weight, and address other common symptoms

• Strategies to lower thyroid antibodies when nothing else has worked

• Nutritional supplements and herbs for Hashimoto’s

• A comprehensive list of the blood tests you should get, along with other specific tests that can help detect your triggers

• What you need to do to achieve optimal adrenal health

• Natural treatment options for viruses, pathogenic bacteria, parasites, Candida, and SIBO

Click Here to order the book “Hashimoto’s Triggers”

Save My Thyroid Podcast Review

I have a podcast called "Save My Thyroid", where I discuss how people with hyperthyroidism and Hashimoto's can save their thyroid and regain their health. And during each edition of this newsletter I'll briefly discuss a recent podcast episode.

In a recent Q & A podcast episode I answered the question “How can estrogen dominance be addressed?” Estrogen dominance doesn’t always show up on a standard lab panel but it can quietly stall thyroid function, lead to thyroid nodules, and leave you feeling foggy or stuck. In this episode, I walk through the three main drivers of estrogen buildup, how to spot hidden signs of poor detox, and why your gut and liver play such a key role. I also share specific steps like nutritional, supplemental, and lifestyle-based strategies to help support healthy estrogen metabolism without overcorrecting.

It’s a thoughtful look at a common issue that doesn’t get talked about enough, especially in thyroid care. Tune in now!

Understand Your Tests

Understanding Oxalates

In 2016, I attended a workshop hosted by Great Plains Laboratory (now known as Mosaic Diagnostics) and completed my very first Organic Acids Test (OAT). Overall, my results looked fairly good, aside from some mild Candida overgrowth and elevated oxalic acid levels.

As discussed in the main section of this newsletter, several factors can contribute to high oxalate levels, including fungal overgrowth (such as Candida), genetic variations in oxalate metabolism, and dietary choices. In my case, I was confident the culprit was the large spinach-loaded green smoothies I had been consuming daily. After eliminating spinach and retesting, my oxalate levels returned to a healthy range.

The Three Oxalate Metabolites

The OAT evaluates three key oxalate-related metabolites: glyceric, glycolic, and oxalic acid. Each provides unique insight into oxalate metabolism:

Glyceric Acid. Glyceric acid can be elevated in individuals with genetic defects in the metabolism of hydroxyproline or due to rare metabolic disorders, such as primary hyperoxaluria type II (PH2).

Mild elevations are sometimes seen when there is increased collagen breakdown (for example, during inflammation or tissue injury).

While not commonly high due to diet alone, a notable elevation warrants further investigation into inherited metabolic issues or liver dysfunction.

Glycolic Acid. Glycolic acid is a precursor to oxalic acid, meaning elevated levels can indicate the body is producing more oxalate internally, independent of diet.

Increased glycolic acid may reflect oxidative stress, genetic polymorphisms, or a block in specific metabolic pathways (such as those involving the AGXT gene).

Persistently high levels suggest the need for further evaluation of metabolic function, antioxidant status, and possible genetic testing for oxalate-related enzyme deficiencies.

Oxalic Acid. Oxalic acid is the end product and the most clinically significant marker because high levels can lead to:

• Kidney stone formation (calcium oxalate stones)

• Joint and connective tissue irritation

• Binding of essential minerals like calcium and magnesium, leading to potential deficiencies

• Increased inflammation and oxidative stress, particularly in individuals with autoimmune conditions

Patient Case Studies

Patient Case #1 – Normal Oxalate Profile

This patient’s OAT revealed all three oxalate metabolites within normal ranges. This represents a well-balanced oxalate metabolism, with:

• No significant dietary oxalate overload

• No significant yeast overgrowth

• No obvious genetic or metabolic issues

In these cases, no specific oxalate-related interventions are needed beyond maintaining a balanced, varied diet.

Patient Case #2 – Elevated Oxalic Acid

This patient presented with isolated high oxalic acid but normal glyceric and glycolic acids. The most common reasons for this pattern include:

• High-oxalate diet (spinach, nuts, beets, etc.)

• Candida or mold overgrowth, as these microbes can produce oxalic acid

• Fat malabsorption, which can increase oxalate absorption in the gut

Intervention typically includes:

• Reducing or rotating high-oxalate foods

• Addressing fungal overgrowth if present

• Supporting fat digestion with digestive enzymes or bile acids, if malabsorption is a factor

Patient Case #3 – Elevated Oxalic and Glycolic Acid

In this case, both oxalic acid and glycolic acid were significantly elevated, suggesting a systemic metabolic imbalance rather than diet alone. Potential underlying causes include:

• Genetic polymorphisms in enzymes responsible for glyoxylate metabolism

• Vitamin B6 deficiency, impairing conversion pathways

• Oxidative stress or mitochondrial dysfunction, increasing endogenous oxalate production

Treatment considerations:

✔Ensuring adequate vitamin B6 intake, which supports oxalate metabolism

✔Addressing oxidative stress with antioxidants (e.g., vitamin C, NAC, glutathione precursors)

✔Running additional genetic or metabolic tests, if symptoms (e.g., recurrent kidney stones, joint pain) persist

Ask Dr. Eric

During every issue I'll answer a question or two that I think can benefit most people with a thyroid or autoimmune thyroid condition. If you'd like for me to consider your question for a future edition of this newsletter email your question to [email protected].

QUESTION: WHICH ESSENTIAL OILS CAN BENEFIT THE GUT AND THYROID?

Dr. Eric, I'd love to know which essential oils can benefit the gut and thyroid health?

Thanks for your question! When it comes to using essential oils, it’s important to remember that these plant-based extracts are highly concentrated, and should always be diluted before applying to the skin. Common carrier oils include fractionated coconut oil and sesame oil to prevent skin irritation while still delivering therapeutic benefits.

Essential oils can influence many systems in the body, including the thyroid, immune system, and gut microbiome. Below, we’ll explore some of the most promising essential oils for thyroid support and gut health, backed by scientific studies where available.

Essential Oils That May Support Thyroid Health

Myrrh. Myrrh oil is known for its anti-inflammatory and immune-modulating properties. While there's no direct evidence that applying myrrh oil to the thyroid gland improves hormone levels, it may help calm inflammation related to autoimmune thyroid conditions such as Graves’ disease and Hashimoto’s thyroiditis.

Research shows that myrrh can reduce pro-inflammatory cytokines, including TNF-α and IL-6,^1,2 both of which are elevated in autoimmune conditions.

Lemongrass. Lemongrass essential oil has both anti-inflammatory and antifungal properties. It’s particularly useful for individuals with chronic infections or inflammatory conditions.

One study found that lemongrass inhibited key inflammatory markers like IL-1β and IL-6, which play a role in thyroid autoimmunity.³ Another study suggests that its main compounds—citral and geranial—may be useful in treating allergic and inflammatory diseases.⁴

Frankincense. Frankincense oil, derived from the Boswellia tree, is rich in boswellic acids, which have been shown to modulate the immune system.

In autoimmune thyroid conditions, Th17 cells and their related cytokines can worsen inflammation. A 2014 study found that boswellic acids reduce Th17 cytokines while increasing regulatory T cells (Tregs),⁵ which are essential for maintaining immune tolerance. Some individuals also claim frankincense helps reduce thyroid nodules, though this is anecdotal.

Essential Oils That May Support Gut Health and the Microbiome

Peppermint Oil. Peppermint oil is one of the most researched essential oils for gut health. In terms of its impact on the gut microbiome, peppermint oil exhibits broad-spectrum antimicrobial activity, and it works by:

Inhibiting harmful bacteria without broadly disrupting beneficial species

Reducing inflammation triggered by bacterial toxins like lipopolysaccharides (LPS)

Improving motility in the digestive tract, helping to reduce bacterial stasis that leads to dysbiosis

Additionally, peppermint oil’s main active compound, menthol, has been shown to have antispasmodic, anti-inflammatory, and antimicrobial effects.⁶

Geranium Oil. Geranium essential oil contains compounds such as geraniol and geranyl acetate, which have been studied for their antifungal and antimicrobial properties.

One study demonstrated that geranium oil can inhibit the growth of Candida albicans—a yeast that often overgrows in the gut, especially after antibiotic use.⁷ It also shows effectiveness against both gram-positive and gram-negative bacteria, which may help rebalance the microbiome and reduce gut-related inflammation.⁸

Lavender Oil. While lavender is best known for its calming and sleep-promoting effects, it also has notable benefits for gut health. Lavender oil has been shown to:

Inhibit inflammation triggered by LPS, which is produced by harmful bacteria.⁹

Exhibit antimicrobial and antifungal activity, helping to reduce overgrowths in the gut. ^10,11

In addition, lavender may indirectly benefit the gut through the gut-brain axis, reducing stress and improving vagal tone—both of which support digestion and microbial diversity.

Additional Thyroid-Related Resources

Click Here for Is the Water You Drink Helping or Harming Your Gut and Thyroid?

Click Here for The Impact of Toxic Superfoods on Thyroid Health (episode 98)

Click Here to access hundreds of thyroid-related articles and blog posts

Click Here to join the Graves’ disease and Hashimoto’s community

Click Here to purchase one of Dr. Eric’s thyroid-related books

Click Here to work with Dr. Eric and his team

📚References:

Click Here to access the references

That’s a wrap