Dedication
With deep appreciation, this book is dedicated to the memory of the late Dr. Ray Peat, whose exceptional research and invaluable guidance were instrumental in my recovery from hypothyroidism and the restoration of my health.
Raymond Franklin Peat (1936-2022), a distinguished American scholar with a Ph.D. in biology, dedicated over half a century to investigating the intricate relationship between nutrition, hormones, and health. His pioneering contributions in the fields of metabolism and thyroid function have left an indelible impact on countless lives, including my own.
Dr. Peat viewed optimal thyroid function as a fundamental element of overall wellness. He contended that many individuals were experiencing a variety of symptoms that could be effectively addressed through accurate diagnosis and targeted treatment of hypothyroidism.
In his extensive research, Dr. Peat examined topics such as the best dietary practices for promoting thyroid health, effective thyroid medications, and the role of related hormones like natural progesterone and pregnenolone.
The goal of this book is to provide a thorough yet accessible explanation of Dr. Ray Peat's diagnostic techniques for hypothyroidism. It explores his perspectives on interpreting thyroid blood tests and elaborates on his method of using pulse and temperature metrics in conjunction with symptom analysis for a comprehensive assessment of thyroid functionality.
Benedicte Mai Lerche
December 2023
Introduction
In my early twenties, I faced the significant challenge of severe hypothyroidism, also known as underactive thyroid function or low metabolism. Confronted with debilitating symptoms and in pursuit of effective treatment, I embarked on a transformative journey that reshaped my life.
I was fortunate to encounter Dr. Ray Peat, a renowned expert in nutrition, metabolism, and hormonal health. Discovering his work marked a turning point in my battle with hypothyroidism, providing the crucial knowledge I needed to regain my health.
Following Dr. Peat's advice, I adopted dietary changes, thyroid medications, and hormonal supplements, which all helped revitalize my metabolism.
Inspired by my recovery, I pursued biochemistry in university and later founded my website, biochemnordic.com. Here, and in my book series “Healing Metabolism”, I share Dr. Peat's health principles and offer insights into nutrition, metabolism, and hormones.
For more on my health journey and how I applied Dr. Peat’s philosophies, I invite you to read my first book, “How I Overcame Hypothyroidism”.
This second book aims to deepen your understanding of Dr. Peat's views on thyroid testing and his methods for detecting Hypothyroidism.
The book is structured as follows:
Chapter 1: Lays the foundation for understanding thyroid physiology, detailing the role of the thyroid gland and the interplay between thyroid hormones (T4, T3) and TSH, with a focus on the active thyroid hormone, T3.
Chapter 2: Delves into the consequences of underactive thyroid function, reflecting Dr. Peat's insights on various causes of hypothyroidism and their effects on the body. It offers a detailed list of symptoms associated with hypothyroidism and discusses the common triggers for this condition. Additionally, the chapter addresses the role of reverse T3 (rT3) and explores Hashimoto's thyroiditis.
Chapter 3: Delves into thyroid blood tests, providing historical context for the reference ranges of thyroid function tests. It explains the crucial distinction between 'reference ranges' and 'optimal ranges' for these tests, emphasizing that hypothyroidism can still be present even if blood test results are within the 'normal' range. The chapter includes recommendations for reliable thyroid blood tests, aimed at enhancing communication with your healthcare provider. Additionally, it offers guidance on interpreting test results, helping readers gain a deeper understanding of their thyroid function.
Chapter 4: Discusses methods for assessing thyroid function at the cellular level, using pulse rate and body temperature as key indicators. The effect of stress hormones on these measurements is clarified. Detailed guidelines for tracking pulse and temperature are provided. The chapter also discusses different types of devices suitable for these measurements.
Chapter 5: Introduces schemas specifically designed to aid in tracking your pulse and temperature daily, as well as over time, along with a dedicated checklist for assessing symptoms related to hypothyroidism. These tools are invaluable for methodically monitoring and comprehending the changes in your thyroid function.
Chapter 6: Provides an introductory overview of Dr. Peat's health philosophy, along with basic guidance for addressing hypothyroidism. It briefly outlines his fundamental ideas, effectively setting the stage for further exploration. This chapter serves as a stepping stone for those interested in delving deeper into Dr. Peat's methodologies in future readings or research.
Chapter 1: Thyroid Physiology
The Thyroid Gland
To delve into the realm of thyroid testing, it's essential to first grasp key facets of thyroid physiology. This chapter is dedicated precisely to that purpose.
Thyroid function refers to metabolism or the metabolic rate, which is a medical term indicating the process through which cells convert food into energy (Barnes & Galton, 1976, p. 3).
Metabolism is regulated by the thyroid hormones, which are produced and released by the thyroid gland (Society of Endocrinology, 2020).
Located in the front of the throat, the human thyroid gland (Figure 1) has a butterfly shape (Barnes & Galton, 1976, p. 3). It is a small endocrine gland that produces and releases triiodothyronine (T3), the active thyroid hormone, and thyroxine (T4), a prohormone or storage hormone.
Collectively, T4 and T3 are known as the thyroid hormones (Society of Endocrinology, 2020). The thyroid gland is known to secrete more T4 than T3 (American Thyroid Association, 2023a). As per Dr. Peat, T4 and T3 are released in a ratio of about 3:1, which corresponds to 75% T4 and 25% T3 (Peat, 2001a, p. 73).
Figure 1: A sketch of the human thyroid gland, illustrating its distinctive butterfly shape and its location at the front of the throat.
Interplay of T4, T3, and TSH
Thyroid-stimulating hormone (TSH), originating from the pituitary gland in the brain, stimulates the thyroid gland to produce and release thyroid hormones into the bloodstream (Society of Endocrinology, 2020); (Vander, et al., 2001, p. 280).
The thyroid hormones and TSH operate within a negative feedback loop, which is illustrated in Figure 2, see below.
A low TSH level serves as an indicator of adequate blood levels of T4 and T3. Conversely, when T4 and T3 levels decrease, it triggers an increase in TSH (Vander, et al., 2001, p. 281).
Consequently, the TSH value is utilized as a means to evaluate the function of the thyroid gland (Peat, 2008, p. 2). I will return to the issue of measuring blood levels of TSH, T4, and T3 later in this book.
Figure 2: Demonstrating the relationship between TSH and thyroid hormones (T4 and T3). Inadequate levels of T4 and T3 result in an increase in TSH levels, as shown in the first image. While optimal levels of these hormones cause a decrease in TSH, as depicted in the second image.
The Importance of T3
When discussing metabolism, it is crucial to always keep in mind that T3 is the active thyroid hormone, which affects cells and regulates metabolism, whereas T4 is a pro-hormone for T3 (Society of Endocrinology, 2020).
Once secreted by the thyroid gland, T4 can be converted to the active thyroid hormone T3 by specific enzymes in other organs and tissues (Society of Endocrinology, 2020). Most of this conversion occurs in the liver, which allows the liver to regulate thyroid function (Peat, 2001a, p. 73).
T3's main function is to energize cells, thereby facilitating the essential life processes of the body's tissues and organs (Vander, et al., 2001, p. 267).
T3 controls the metabolic rate, which refers to the speed at which cells utilize oxygen (6O2) to transform nutrients into carbon dioxide (CO2), water (H2O), heat, and adenosine triphosphate (ATP), the latter serves as a biological form of energy.
To exemplify, consider the metabolic process involving glucose, represented by the following equation (Vander, et al., 2001, pp. 619-620; Boston University School of Public Health, 2017):
ATP acts as an energy source within the body, powering essential cellular functions and reactions (Vander, et al., 2001, pp. 619-620).
Peat highlighted the critical importance of abounded energy for maintaining the correct structure and functionality of the body's tissues and organs (Peat, 2001a, pp. 1-5).
He proposed that diseases arise when there's an imbalance between the body's energy supply and the demands of its environment (Peat, 2001a, pp. 1-5). Specifically, he pointed out that hypothyroidism, marked by low energy levels, is instrumental in triggering harmful degenerative processes (Peat, 2001d, p. 16). Since hypothyroidism impacts all cells and tissues, it presents a range of symptoms. The next chapter provides a detailed list of symptoms associated with reduced thyroid function.