Many Americans suffer from symptoms such as cold hands and feet, low body temperature, sensitivity to cold, a feeling of always being chilled, headaches, insomnia, dry skin, puffy eyes, hair loss, brittle nails, joint aches, constipation, mental dullness, fatigue, frequent infections, hoarse voice, ringing in the ears, dizziness, loss of libido, and weight gain, which is sometimes uncontrollable. Approximately 65 percent of the U. S. population is overweight; 30 percent is clinically obese. Research is pointing to the fact that an under active thyroid might be the number one cause of weight problems, especially among women, in the US today.
In 1995, researchers studied 25,862 participants at the Colorado statewide health fair. They discovered that among patients not taking thyroid medication, 8.9 percent were hypothyroid (under-active thyroid) and 1.1 percent were hyperthyroid (over-active thyroid). This indicates 9.9 percent of the population had a thyroid problem that had most likely gone unrecognized. These figures suggest that nationally, there may be as many as 13 million Americans with an undiagnosed thyroid problem.
In her book Living Well With Hypothyroidism: What Your Doctor Doesn’t Tell You... That You Need to Know, Mary Shomon quotes endocrinologist Kenneth Blanchard, M.D., of Lower Newton Falls, Massachusetts as saying, “The key thing is... doctors are always told that TSH is the test that gives us a yes or no answer. And, in fact, I think that’s fundamentally wrong. The pituitary TSH is controlled not just by how much T4 and T3 is in circulation, but T4 is getting converted to T3 at the pituitary level. Excess T3 generated at the pituitary level can falsely suppress TSH.” Hence, many people who are simply tested for TSH levels and are found to be within “normal” range are, in fact, suffering from thyroid problems that are going undetected.
Ridha Arem, MD, Associate Professor of Medicine in the Division of Endocrinology and Metabolism at Baylor College of Medicine, agrees. He says that hypothyroidism may exist despite “normal range” TSH levels. In his book The Thyroid Solution he says:
Many people may be suffering from minute imbalances that have not yet resulted in abnormal blood tests. If we included people with low-grade hypothyroidism whose blood tests are normal, the frequency of hypothyroidism would no doubt exceed 10 percent of the population. What is of special concern, though, is that many people whose test results are dismissed as normal could continue to have symptoms of an under active thyroid. Their moods, emotions, and overall well-being are affected by this imbalance, yet they are not receiving the care they need to get to the root of their problems. Even if the TSH level is in the lower segment of normal range, a person may still be suffering from low-grade hypothyroidism.
Thus, if we were to include those who may be suffering from “low-grade hypothyroidism,” the number could well be double the 13 million estimate from the Colorado study.
What is Causing This Epidemic?
While more research needs to be done, it is generally accepted that diet plays a major role in thyroid health. For decades we have known that low iodine intake leads to low thyroid function and eventually to goiter. Iodized salt was intended to solve this problem, but it has not been the answer. There are a number of foods known as goitrogens that block iodine. Two goitrogens are quite prevalent in the American diet—peanuts and peanut butter and soybeans used most often in prepared foods as textured vegetable protein (a refined soy food) and soybean oil.
The rise of industrialization, corporate farming, and mass production of food has drastically changed our food supply from what our ancestors ate. Many studies show the detrimental effects of refined sugars and grains on our health. These foods are very taxing on the thyroid gland, and we consume them in large quantities.
Environmental stress such as chemical pollutants, pesticides, mercury, and fluoride are also tough on the thyroid. A growing body of evidence suggests that fluoride, which is prevalent in toothpaste and water treatment, may inhibit the functioning of the thyroid gland. Additionally, mercury may diminish thyroid function because it displaces the trace mineral selenium, and selenium is involved in conversion of thyroid hormones T4 to T3.
The Truth About Fats and Oils
Many dietary oils can negatively affect thyroid health. We cook with them almost every day and they are plentiful in commercially prepared foods. Expeller-pressed or solvent-extracted oils only became a major part of the American diet in the last century. It is possible they are among the worst offenders when it comes to the thyroid. They are known as vegetable oils or polyunsaturated oils. The most common source of these oils used in commercially prepared foods is the soybean.
Large-scale cultivation of soybeans in the United States began after World War II and quickly increased to 140 billion pounds per year. Most of the crops are produced for animal feed and soy oil for hydrogenated fats such as margarine and shortening. Today, it is nearly impossible to eat at restaurants or buy packaged foods that don’t have soy oil in the ingredients. Often labels simply state “vegetable oil.”
Ray Peat Ph.D., a physiologist who has worked with progesterone and related hormones since 1968, says that the sudden surge of polyunsaturated oils into the food chain post World War II has caused many changes in hormones. He writes:
Their [polyunsaturated oils] best understood effect is their interference with the function of the thyroid gland. Unsaturated oils block thyroid hormone secretion, its movement in the circulatory system, and the response of tissues to the hormone. When the thyroid hormone is deficient, the body is generally exposed to increased levels of estrogen. The thyroid hormone is essential for making the ‘protective hormones’ progesterone and pregnenolone, so these hormones are lowered when anything interferes with the function of the thyroid. The thyroid hormone is required for using and eliminating cholesterol, so cholesterol is likely to be raised by anything which blocks the thyroid function.
There is a growing body of research concerning soy’s detrimental affect on the thyroid gland. Much of this research centers on the phytoestrogens ("phyto" means plant) that are found in soy. In the 1960s when soy was introduced into infant formulas, it was shown that soy was goitrogenic and caused goiters in babies. When iodine was supplemented, the incidence of goiter reduced dramatically. However, a retrospective epidemiological study by Fort, et al. showed that teenaged children with a diagnosis of autoimmune thyroid disease were significantly more likely to have received soy formula as infants (18 out of 59 children; 31 percent) when compared to healthy siblings (nine out of 76, 12 percent) or control group children (seven out of 54; 13 percent).
When healthy individuals without any previous thyroid disease were fed 30 grams of pickled soybeans per day for one month, Ishizuki, et al. reported goiter and elevated individual thyroid stimulating hormone (TSH) levels (although still within the normal range) in thirty-seven healthy, iodine-sufficient adults. One month after stopping soybean consumption, individual TSH values decreased to the original levels and goiters were reduced in size.
Traditionally, polyunsaturated oils such as soybean oil have been used for livestock feed because they cause the animals to gain weight. These oils are made up of what is known as long chain fatty acids—the kind of fatty acids that promote weight gain. In the North Carolina State University's Extension Swine Husbandry 1998-2000 Departmental report, for example, was a study entitled “EFFECT OF DIETARY FAT SOURCE, LEVEL, AND FEEDING INTERVAL ON PORK FATTY ACID COMPOSITION” by M.T. See and J. Odle. Ironically, since the market in its low-fat dogma of recent years is demanding leaner meats, this study showed that one could produce leaner meat and reduce the weight on swine by reducing their intake of soy oil and substituting it with saturated animal fat!
According to Dr. Ray Peat, the fattening effect of polyunsaturated oils (primarily soy and corn) is due to the presence of Linoleic and linolenic acids, long-chain fatty acids, which have an anti-thyroid effect. Peat says:
Linoleic and linolenic acids, the “essential fatty acids,” and other polyunsaturated fatty acids, which are now fed to pigs to fatten them, in the form of corn and soy beans, cause the animals’ fat to be chemically equivalent to vegetable oil. In the late 1940s, chemical toxins were used to suppress the thyroid function of pigs, to make them get fatter while consuming less food. When that was found to be carcinogenic, it was then found that corn and soy beans had the same antithyroid effect, causing the animals to be fattened at low cost. The animals’ fat becomes chemically similar to the fats in their food, causing it to be equally toxic, and equally fattening.
Of course in the 1940s the fat from pigs (lard) was highly desirable, as were most saturated fats. Today, saturated fats are fed to pigs to keep them lean, while most people buy polyunsaturated soy and corn oils in the grocery stores as their primary cooking oil! So we have a population now characterized by lean pigs and obese people.
Coconut Oil: A Healthy Choice for the Thyroid
Coconut oil, on the other hand, is a saturated fat made up primarily of medium chain fatty acids. Also known as medium chain triglycerides (MCTs), medium chain fatty acids are known to increase metabolism and promote weight loss. Coconut oil can also raise basal body temperatures while increasing metabolism. This is good news for people who suffer with low thyroid function. We have seen many testimonies to this effect.
Coconut Oil and Oxidative Stress
One of the reasons the long chain fatty acids in vegetable oils are so damaging to the thyroid is that they oxidize quickly and become rancid. Food manufacturers know about this propensity towards rancidity and, therefore, highly refine their vegetable oils. Considerable research has shown that trans fatty acids, present when vegetable oils are highly refined (hydrogenated or partially hydrogenated), are especially damaging to cell tissue and can have a negative affect on the thyroid as well as health in general. Because the longer chain fatty acids are deposited in cells more often as rancid and oxidizing fat, impairment of the conversion of thyroid hormone T4 to T3 occurs, which is symptomatic of hypothyroidism. To create the enzymes needed to convert fats to energy, T4 must be converted to T3.
Dr. Ray Peat says:
When the oils are stored in our tissues, they are much warmer, and more directly exposed to oxygen than they would be in the seeds, and so their tendency to oxidize is very great. These oxidative processes can damage enzymes and other parts of cells, and especially their ability to produce energy. The enzymes which break down proteins are inhibited by unsaturated fats; these enzymes are needed not only for digestion, but also for production of thyroid hormones, clot removal, immunity, and the general adaptability of cells. The risks of abnormal blood clotting, inflammation, immune deficiency, shock, aging, obesity, and cancer are increased. Thyroid [hormones] and progesterone are decreased.
Since the unsaturated oils block protein digestion in the stomach, we can be malnourished even while “eating well.” There are many changes in hormones caused by unsaturated fats. Their best understood effect is their interference with the function of the thyroid gland. Unsaturated oils block thyroid hormone secretion, its movement in the circulatory system, and the response of tissues to the hormone. Coconut oil is unique in its ability to prevent weight-gain or cure obesity, by stimulating metabolism. It is quickly metabolized, and functions in some ways as an antioxidant.
Because coconut oil is saturated and very stable (unrefined coconut oil has a shelf life of about three to five years at room temperature), the body is not burdened with oxidative stress as it is with the vegetable oils. Coconut oil does not require the enzyme stress that vegetable oils do, preventing T4 to T3 hormone conversion, not only because it is a stable oil, but also because it is processed differently in the body and does not need to be broken down by enzyme dependent processes as do long chain fatty acids. Also, since the liver is the main place where damage occurs from oxidized and rancid oils that cause cell membrane damage, and since the liver is where much of the conversion of T4 to T3 takes place, eliminating long chain fatty acids from the diet and replacing them with medium chain fatty acids found in coconut oil can, in time, help in rebuilding cell membranes and increasing enzyme production that will assist in promoting the conversion of T4 to T3 hormones.