Did you know that poor thyroid function can impact the heart? It turns out that the thyroid plays a big role in regulating cardiac function and blood lipids. If you have high LDL cholesterol, high blood pressure, or elevated inflammatory markers (all risk factors for heart disease), it may be a sign that your thyroid could use some attention.

Research shows that people with low T3 levels (the active form of thyroid hormone) have a higher risk of dying from heart disease, so getting to the root matters!

If a thyroid imbalance is driving your cardiovascular issues, the best approach is to treat the thyroid rather than just masking the symptoms with drugs that lower blood pressure or cholesterol.

This is the heart of what we do at GrassRoots Functional Medicine: get to the root cause of symptoms and health conditions. 

Types of Thyroid Imbalance 

In order to understand the ripple effect of thyroid imbalance on cardiovascular health, we need a quick primer on what the thyroid does and the types of thyroid conditions. The thyroid is the body’s master regulator of metabolism. In fact, every single cell in your body has receptors for thyroid hormone!

When the thyroid isn’t making enough hormones it’s known as hypothyroidism and everything in the body slows down. You may feel tired and notice hair loss, depression, constipation, and feeling cold all the time. Hyperthyroidism, when the thyroid goes into overdrive and overproduces hormones, creates symptoms including anxiety, hyperactivity, and inability to sleep.

Types of Thyroid Dysfunction

The majority of thyroid dysfunction is autoimmune in nature, meaning that the immune system is attacking your thyroid gland and causing it to underproduce or overproduce hormones (Hashimoto’s or Graves’ disease, respectively).

The Thyroid-Heart Connection 

Thyroid hormones tell the heart how to relax and contract. In hypothyroidism, the heart muscle pumps less blood per beat, doesn’t relax as well, and becomes weakened over time, which can eventually lead to heart failure. Blood pressure also increases due to the blood vessels becoming stiff. 

Since thyroid hormone speeds everything up, people with hyperthyroidism can experience increased heart rate, palpitations, and high blood pressure. Over time, this increased demand on the heart muscle can lead to heart failure when the heart can no longer keep up with the stress being put on it. Fortunately, appropriate treatment of the thyroid will allow the cardiovascular system to recover.

The autoimmune component that frequently contributes to thyroid issues also plays a role in heart disease risk. This is because when your body attacks itself, as occurs in autoimmunity, it creates a lot of systemic inflammation and oxidative stress. Free radicals, which are part of the body’s inflammatory response, get out of control if they are not balanced by adequate intake of antioxidants from the diet. In the bloodstream, free radicals oxidize LDL cholesterol, and these oxidized cholesterol particles damage the sensitive lining of the blood vessels, setting the stage for plaque formation and cardiovascular disease.  

Your Thyroid’s Impact on High Cholesterol

Elevated total and LDL cholesterol is another telltale sign of low thyroid function. In fact, prior to statins, doctors treated patients with high cholesterol by prescribing thyroid hormone! Today, people with high cholesterol are too often sent on their way with a statin prescription, and the underlying cause, such as low thyroid, is never investigated or resolved. 

When the body is functioning optimally, the liver filters excess cholesterol from the bloodstream and makes it into bile, which is then eliminated in the stool. In hypothyroidism, the liver clears less cholesterol from the blood, resulting in higher levels left circulating in your body. The good news is that addressing thyroid imbalances has a positive ripple effect on blood lipids.

A 2014 study found that three-quarters of people with hypothyroidism and high cholesterol had their cholesterol normalize by treating their thyroid.

Holistic Solutions to Support Thyroid & Heart Health

When it comes to treating the root cause of thyroid and cardiovascular problems, diet and lifestyle have a huge role to play. The thyroid and heart both rely on a broad range of nutrients to function optimally, and deficiencies in these nutrients, as well as too many inflammatory foods, environmental toxins, and stress can all knock these systems out of balance.

  • Eat a nutrient-dense diet: Iodine, zinc, selenium, and iron are important for thyroid function and are found abundantly in fish and seafood, high quality grass-fed meats, and nuts and seeds including pumpkin seeds (zinc) and Brazil nuts (selenium) and a high-quality multivitamin. Antioxidants are also incredibly important for both the thyroid and heart, as they counteract the oxidative stress associated with autoimmune thyroid conditions and vascular damage. Rich sources of antioxidants include a rainbow of brightly colored vegetables and fruits, especially berries, citrus fruits, herbs and spices like parsley, cilantro, turmeric, and ginger, and dark green leafy vegetables.


  • Reduce inflammatory foods: Refined vegetable oils and processed sugar and flour all contribute to chronic, low-grade inflammation. Corn, canola, cottonseed, soybean, and safflower oils are particularly insidious sources of inflammatory compounds in the Standard American Diet, as they are added to most prepackaged foods, salad dressings, mayonnaise, cooking sprays, and are the go-to cooking oils used in restaurants. Replacing these oxidized oils with healthier cooking fats, such as olive oil, coconut oil, and grass-fed butter is an excellent first step toward implementing an anti-inflammatory, heart- and thyroid-protective diet.
  • Make autoimmune-specific dietary changes: In cases where the body is attacking its own cells, research shows that a gluten-free diet decreases thyroid antibodies and improves thyroid hormone production. Because of gluten’s ability to promote “leaky gut” and intestinal inflammation, following a gluten-free diet is a good place to start for most people with autoimmunity.
  • Manage stress: Stress has been associated with heart disease, thyroid fatigue and autoimmunity. Finding ways to both reduce the stressors in your life and manage the ones you can’t avoid through mindfulness practices, social connection, and time in nature, among other techniques, is a key component of any well-rounded approach to healing.

Dietary and lifestyle changes like the ones above go a long way toward improving heart health, but sometimes it’s necessary to dig a bit deeper. 

A Root-Cause Approach to Thyroid & Cardiovascular Health

At GrassRoots, we take a holistic approach to cardiovascular and endocrine health. Rather than treating symptoms with bandaids, our team of functional medicine practitioners digs deep by evaluating functional lab testing and taking an extensive medical history. Just as important, we are here for you each step of the way as you implement dietary and lifestyle changes and add in targeted supplements and medications (if needed) to address your unique clinical picture. 

We believe that all systems of the body are intimately interconnected, and by identifying and addressing the imbalances keeping you stuck you can thrive and live a vibrant, fulfilling life. Explore our Adaptation programs or schedule a discovery call to learn more. 

About the Author: Dr. Seth Osgood is a Doctor of Nursing Practice, Board Certified Family Nurse Practitioner and Institute of Functional Medicine (IFM) Certified Practitioner. Dr. Osgood received his post-graduate training in Functional Medicine through the IFM and from working with Dr. Amy Myers. He has helped people from around the world improve their health utilizing a Functional Medicine approach.