What Your Thyroid May Be Trying to Tell You: A Conversation with Dr. Nicholas Hedberg
By Dr. Cynthia Libert, Functional Medicine Physician | Caring for the Body, Center for Functional Medicine
Thyroid disease is one of the most common and most undertreated conditions I see in my practice. So many women — and men — come to me having been told their labs are "normal," yet they are still exhausted, gaining weight, constipated, struggling to think clearly. They've been prescribed Synthroid and sent on their way, and something still isn't right.
I wanted to dedicate an episode to this topic, and I couldn't think of a better guest than my friend and colleague Dr. Nicholas Hedberg. Dr. Hedberg is a board-certified chiropractic internist, a board-certified nutritionist, and the founder of both the Immune Restoration Center here in Asheville and the Hedberg Institute, a functional medicine education platform. He also literally wrote the book on this subject — The Complete Thyroid Health and Diet Guide — which is actually how I first learned about him.
Our conversation was rich, and I want to share some of the most important takeaways with you here.
Thyroid 101: Why It Matters
As Dr. Hedberg explained, "Thyroid hormone is the main regulator of metabolism. Your ability to make energy, to burn fat and carbs and metabolize amino acids — that's all controlled by thyroid."
When thyroid function is sluggish, the symptoms can show up throughout the entire body: fatigue, constipation, depression, dry skin, cold intolerance, brain fog, weight gain, heavy periods, even elevated cholesterol. The brain connection is something I'm always watching for closely. Suboptimal thyroid function can impair attention, focus, and mental processing in ways that can look like early cognitive decline — which is why I make sure thyroid optimization is part of every patient's brain health picture.
The Autoimmune Piece Most Doctors Miss
Here is something that surprised me when I left conventional medicine and started going deeper: approximately 90% of people with hypothyroidism have Hashimoto's disease — an autoimmune condition. In my formal medical training, we focused almost exclusively on the TSH and synthetic T4 replacement. There was virtually no discussion of the autoimmune component or what to do about it.
Dr. Hedberg put it plainly: the key to addressing Hashimoto's is to work on the autoimmunity, not just to balance hormone numbers. The thyroid, he explained, is especially sensitive to environmental toxins and infections — more so than many other organs. Triggers can include heavy metals like mercury, thyroid-disrupting chemicals found in plastics and flame retardants, and infections such as H. pylori, Epstein-Barr virus, and the intestinal parasite Blastocystis hominis.
Research has shown, for example, that treating Blastocystis hominis can actually improve thyroid antibody levels and thyroid hormone numbers. And treating H. pylori in hypothyroid patients often reduces the amount of thyroid medication they need. These are the kinds of root-cause connections that conventional medicine tends to miss entirely.
Healing the Gut Is Central
For most patients with Hashimoto's, healing begins in the gut. Intestinal dysbiosis and leaky gut are strongly associated with the condition, and Dr. Hedberg's approach starts with diet: removing inflammatory foods like gluten, dairy, and sugar, often through a paleo or autoimmune paleo protocol. He also uses triple probiotic therapy — a combination of a lactobifido blend, Saccharomyces boulardii, and a spore-based probiotic — noting that a recent meta-analysis found probiotic use in hypothyroid patients improved TSH, T4, and T3 levels.
Key micronutrients also matter: iron, zinc, selenium, and iodine are among the most important for thyroid function, and deficiencies are common. Dr. Hedberg recommends approximately 200 micrograms of selenomethionine daily, and notes that optimizing protein intake is one of the best ways to address tyrosine deficiency naturally.
Clearing Up Two Common Myths
On ashwagandha: There is a lot of misinformation circulating online suggesting that ashwagandha is harmful for people with Hashimoto's. Dr. Hedberg addressed this directly: "In traditional, classical herbalism, ashwagandha is one of the most fundamental herbs for hypothyroidism." The concerns about it stimulating autoimmunity reflect a misunderstanding of how it works. It acts as a modulator, not a driver of autoimmune activity. He has used it successfully for 20 years without issue.
On goitrogenic foods: Another common fear is that people with thyroid conditions must avoid all cruciferous vegetables. Dr. Hedberg clarified that goitrogenic foods — brassica vegetables, and to some extent soy — are safe in moderation when cooked properly. They only become a concern in large, excessive quantities.
The Role of Stress and Self-Care
One point Dr. Hedberg made that I want every patient to hear: stress directly impairs thyroid function. Cortisol and adrenaline both interfere with thyroid hormones. Overtraining is a surprisingly common culprit — the body actually slows the thyroid to conserve resources when pushed too hard. Sleep disruption has a similar effect.
Managing stress through meditation, time outdoors, natural light, and appropriate (not excessive) exercise matters more than many people realize. Adrenal adaptogens like rhodiola and ashwagandha have research supporting their role in improving both stress response and thyroid function.
Thyroid disease is common, but being undertreated or under-evaluated should not be. If you have been told your thyroid is "fine" but you still don't feel well, there may be more to the story.
Ready to take a root-cause approach to your health? Start with a free strategy session with the Caring for the Body team.
Whole-person care. Science-backed. Faith-informed.
This post is adapted from the Re-Think Aging podcast. You can listen to the full episode here: https://www.youtube.cE14: Dr. Nikolas Hedberg, DC: Problems With Your Thyroid? What You Need to Knowom/watch?v=CcEKdv5uOJ0