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A History of Iodine Therapy
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The decline in the use of iodine in medicine began in 1948 when researchers Wolff and Chaikoff published a landmark paper on the thyroid effects of increasing amounts of potassium iodide, injected into rats. The authors stated: “Organic binding of iodine within the glands can be almost completely blocked by raising the level of plasma inorganic iodine (PII) above a certain critical level, which for the rat amounts to about 20 to 35 percent.”16 This effect became known as the Wolff-Chaikoff (W-C) effect. According to the conventional view, high levels of intracellular iodide suppress the transcription of thyroid peroxidase (TPO) enzyme, along with NADPH oxidase, leading to a reduction in the synthesis of thyroid hormone, thyroxin.17 As proof of the W-C effect, the textbooks point to the fact that large amounts of potassium iodide can remedy hyperthyroidism. Another apparent confirmation is the thyroid-suppressing effect of several iodine-containing drugs, of which the most famous is amiodarone, which can cause both under- and overactivity of the thyroid. In a trial that compared amiodarone with other medications for the treatment of atrial fibrillation, biochemical hypothyroidism (as defined by a TSH level of 4.5-10 mU/L) occurred in 25.8 percent of the amiodarone-treated group as opposed to 6.6 percent of the control group (taking placebo or sotalol). Overt hypothyroidism (defined as TSH greater than 10 mU/L) occurred at 5.0 percent compared to 0.3 percent.18
Over time, these observations led to a decline in the use of iodine in medicine. While health officials came to a general agreement that iodine deficiency caused, in increasing order of severity, goiter and hypothyroidism, mental retardation and cretinism, authorities in the U.S. and Europe agreed upon a low Reference Daily Intake (RDI), formerly called the Recommended Dietary Allowance (RDA), of 100-150 mcg per day. This amount will prevent goiters and other overt signs of deficiency but may not be adequate to prevent other conditions of iodine deficiency, and is much lower that the amounts formerly given routinely to patients.
Critics of the W-C effect note that the standard dose of potassium iodide was 1 gram until the mid-1900s, which contains 770 mg of iodine, over five thousand times more than the RDI. For many years physicians used potassium iodide in doses starting at 1.5 to 3 gm and up to more than 10 grams a day, on and off, to treat bronchial asthma and chronic obstructive pulmonary disease, apparently with good results and few side effects. Even today, dermatologists treat certain skin conditions, including fungal eruptions, beginning with an iodine dose of 900 mg a day, followed by weekly increases up to 6 grams a day as tolerated.
But the general use of iodine and iodine compounds in medicine has waned, as has its use as an additive in the food supply. Today’s medical establishment is wary of iodine as are public health officials. Thyroidologists cite the W-C effect and warn that TSH (thyroid stimulating hormone) blood levels can rise with an iodine intake of one milligram or more.
In a 2000 review paper on use of iodine as a water disinfectant, author Joe Hollowell notes that studies indicate marked individual sensitivity to iodine; the most vulnerable to adverse effects are those with underlying thyroid disease and previous low iodine intake. Problems from consumption of iodized water—including both hypothyroidism and hyperthyroidism—usually resolve after consumption is discontinued. A safe dose is 1-2 grams per day, and most can tolerate much higher amounts without problems.19
The Challenge
A challenge towards the reigning attitudes to iodine compounds came in 1997, when Dr. Guy Abraham, a former professor of obstetrics and gynecology at UCLA, mounted what he calls the Iodine Project. He had his company, Optimox Corporation, make Iodoral, the tablet form of Lugol’s solution (which combines iodine and potassium iodide), and he engaged two family practice physicians, Dr. Jorge Flechas (in 2000) in North Carolina and Dr. David Brownstein (in 2003) in Michigan to carry out clinical studies with high doses of the iodine compound.20 The project’s hypothesis is that maintaining whole body sufficiency of iodine requires 12.5 mg a day, an amount similar to what the Japanese consume and over eighty times the RDI of 150 mcg. The conventional view is that the body contains 25-50 mg of iodine, of which 70-80 percent resides in the thyroid gland. Dr. Abraham concluded that whole body sufficiency exists when a person excretes 90 percent of the iodine ingested. He devised an iodine-loading test where one takes 50 mg iodine/potassium iodide and measures the amount excreted in the urine over the next twenty-four hours. He found that the vast majority of people retain a substantial amount of the 50 mg dose. Many require 50 mg per day for several months before they will excrete 90 percent of it. His studies indicate that, given a sufficient amount, the body will retain much more iodine than originally thought, 1,500 mg, with only 3 percent of that amount held in the thyroid gland.
According to Abraham, more than 4,000 patients in this project take iodine in daily doses ranging from 12.5 to 50 mg, and in those with diabetes, up to 100 mg a day. According to these physicians, iodine at these doses does indeed reverse fibrocystic disease; allows diabetic patients to use less insulin and hypothyroid patients to use less thyroid medication; resolves symptoms of fibromyalgia; and stops migraine headaches. They report that the side effects of iodine, including hypo- or hyperthyroidism, allergies, swelling of the salivary glands and thyroid, occur in less than 5 percent.21 Urine tests confirm that iodine at these doses removes the toxic halogens fluoride and bromide from the body.22
They believe that iodism, an unpleasant brassy taste, runny nose, and acne-like skin lesions, is caused by the bromide that iodine extracts from the tissues. Symptoms subside on a lower dose of iodine.
In 2005, Dr. Abraham published a long paper challenging the Wolff-Chaikoff effect. “The W-C effect is supposedly the inhibitory effect of peripheral inorganic iodide (PII) levels equal to or greater than 0.2 mg/L (10-6M) on the organification of iodide by the thyroid gland of rats, resulting supposedly in hypothyroidism and goiter. These rats never became hypothyroid and thyroid hormones were not measured in their plasma. Nevertheless, the W-C effect, which did not even occur in the rats, was extrapolated to humans. The correct interpretation of the results obtained in rats from the W-C experiments is: Iodide sufficiency of the thyroid gland was achieved when serum inorganic iodide levels reached 10-6M . . . . These law-abiding rats refused to become hypothyroid and instead followed their normal physiological response to the iodide load. They were unjustly accused of escaping from the W-C effect. Labeling these innocent rats as fugitives from the W-C effect was a great injustice against these rodents.
“To the disgrace and stupidity of the medical profession, U.S. physicians swallowed the W-C forgery uncritically, which resulted in a moratorium on the clinical use of inorganic, non-radioactive iodine in effective amounts. However, this moratorium did not include toxic organic iodine-containing drugs and radioiodide. The iodophobic mentality prevented further research on the requirement for inorganic, non-radioactive iodine by the whole human body, which turns out to be 100-400 times the very recently established RDA. . . Prior to World War II and the W-C publication, U.S. physicians used Lugol solution safely, effectively and extensively in both hypo- and hyperthyroidism.”23
Abraham cites a 1970 paper which evaluated the effect of Lugol’s solution, administered at five drops (30 mg iodine/iodide) three times a day in five thyrotoxic patients. Following a well-designed protocol, they reported, “It is concluded that the rapid decrease in T4 secretion induced by iodine is not the result of an acute sustained inhibition of T4 synthesis (the Wolff-Chaikoff effect), but rather results from an abrupt decrease in the fractional rate of thyroid T4 release.”24
Abraham thus argues that in hyperthyroidism, iodine/iodide in Lugol’s at a daily dose of 90 mg induced a physiological trend toward normalization of thyroid function, “a beneficial effect, not the fictitious W-C effect as proposed by Wolff and Chaikoff. It is amazing that the W-C effect, which is still mentioned in iodophobic publications, has never been confirmed in rats by other investigators and has never been demonstrated in any animal species.
“In 1948, there was already evidence that the W-C effect, if it was for real in rats (and it was not), did not occur in humans. The Lugol’s solution and saturated solution of potassium iodide (SSKI) were used extensively in medical practice for patients with asthma. The recommended daily amount was 1,000-2,000 mg. This amount was used in patients with asthma, chronic bronchitis, and emphysema for several years. Hypothyroidism and goiter were not common in this group of patients. Those amounts of iodine would have resulted in serum inorganic iodine levels 100 times higher than the serum inorganic iodide levels of 10-6M claimed by Wolff and Chaikoff to result in the W-C effect.”
According to Abraham, iodine in amounts considered “excessive” by endocrinologists today represent only 3 percent of the average daily intake of iodide by 60 million mainland Japanese, a population with a very low incidence of cancer overall, and in particular of the female reproductive organs.
According to Abraham, “Medical iodophobia resulted in the thyroid hormone thyroxine replacing iodine in iodine deficiency-induced simple goiter and hypothyroidism. Thyroxine has been the most prescribed drug in the U.S. for several years. So, the manufacturers of thyroxine benefited tremendously from this deception. It also resulted in the destruction of the thyroid gland by means of radioiodide in patients with hyperthyroidism caused by iodine deficiency, although this condition had previously been treated successfully with Lugol solution. The radioablation of the thyroid gland with radioiodide resulted in 90 percent of these patients becoming hypothyroid within the first year and eventually joining the ever-increasing thyroxine-consuming population. “Supplying thyroid hormones to iodine-deprived individuals masks the iodine deficiency and can result in zombie-like effect. The patients are capable of performing physical work but are not able to think and reason at maximum capacity. An even greater negative effect is realized if iodine deprivation is combined with goitrogen saturation, using the potent goitrogens bromide, fluoride and perchlorate in the food and water supply.
“Iodine is involved in many vital mental and physical functions, and yet whole body sufficiency for iodine has never been determined. Why? Medical textbooks discuss inorganic, non-radioactive iodine only in relation to the most severe deficiencies of this essential element: cretinism, hypothyroidism and endemic goiter. Based on an iodine/iodide loading test developed by the author to assess whole body sufficiency for iodine, the amounts of iodine needed for whole body sufficiency and optimal physical and mental health are 250-1,000 times higher that the amount of iodine needed to control cretinism, hypothyroidism and endemic goiter.”
Thus, according to Abraham and his colleagues, the Wolff-Chaikoff effect is of no clinical significance. An elevated TSH, when it occurs during treatment with Lugol’s solution, is “subclinical.” This means that no signs or symptoms of hypothyroidism accompany its rise. Some people taking milligram doses of iodine, usually more than 50 mg a day, develop mild swelling of the thyroid gland without symptoms. Abraham believes that the vast majority of people, 98 to 99 percent, can take iodine in doses ranging from 10 to 200 mg a day without any clinically adverse effects on thyroid function.
The Debate
With Abraham’s work, and its popularization by physicians such as Jorgas and Brownstein, many health-conscious individuals began taking Lugol’s solution regularly, even without medical supervision. A challenge to this practice came from Dr. Alan Gaby in an editorial published in the Townsend Letter for Doctors and Patients, August/September 2005.25
“Recently, a growing number of doctors have been using iodine supplements in fairly large doses in their practices,” wrote Gaby. “The treatment typically consists of 12 to 50 mg per day of a combination of iodine and iodide, which is 80 to 333 times the RDA of 150 mcg (0.15 mg) per day. Case reports suggest that iodine therapy can improve energy levels, overall well-being, sleep, digestive problems and headaches. People with hypothyroidism who experienced only partial improvement with thyroid hormone therapy are said to do better when they start taking iodine. In addition, fibrocystic breast disease responds well to iodine therapy, an observation that has been documented previously. The reported beneficial effects of iodine suggest that some people have a higher-than-normal requirement for this mineral, or that it favorably influences certain types of metabolic dysfunction.
“While iodine therapy shows promise, I am concerned that two concepts being put forth could lead to overzealous prescribing of this potentially toxic mineral. First is the notion that the optimal dietary iodine intake for humans is around 13.8 mg per day, which is about 90 times the RDA and more than 13 times the ‘safe upper limit’ of 1 mg per day established by the World Health Organization. Second is the claim that a newly developed iodine-load test can be used as a reliable tool to identify iodine deficiency.”
Gaby takes issue with the argument that the optimal human requirement is 13.8 mg per day, by noting that “the idea that Japanese people consume 13.8 mg of iodine per day appears to have arisen from a misinterpretation of a 1967 paper. In that paper, the average intake of seaweed in Japan was listed as 4.6 g (4,600 mg) per day, and seaweed was said to contain 0.3 percent iodine. The figure of 13.8 mg comes from multiplying 4,600 mg by 0.003. However, the 4.6 g of seaweed consumed per day was expressed as wet weight, whereas the 0.3 percent-iodine figure was based on dry weight. Since many vegetables contain at least 90 percent water, 13.8 mg per day is a significant overestimate of iodine intake. In studies that have specifically looked at iodine intake among Japanese people, the mean dietary intake (estimated from urinary iodine excretion) was in the range of 330 to 500 mcg per day, which is at least 2.5-fold lower than 13.8 mg per day.”
Regarding the other argument in support of a high iodine requirement, namely that it takes somewhere between 6 and 14 mg of oral iodine per day to keep the thyroid gland fully saturated with iodine, “. . . it is not clear that loading the thyroid gland or other tissues with all the iodine they can hold is necessarily a good thing. . . Our thyroid glands have developed a powerful mechanism to concentrate iodine, and some thyroid glands (or other tissues) might not function as well after a sudden 90-fold increase in the intake of this mineral. . . relatively small increases in dietary iodine intake have been reported to cause hypothyroidism or other thyroid abnormalities in some people.”
As for the observation that iodine supplementation “promotes the urinary excretion of potentially toxic halogens such as bromide and fluoride. While that effect might be beneficial for some people, it is not clear to what extent it would shift the risk-benefit ratio of megadose iodine therapy for the general population.”
Abraham and colleagues promote the use of the iodine-load test, in which the patient ingests 50 mg of a combination of iodine and iodide and the urine is collected for the next twenty-four hours. The patient is considered to be iodine-deficient if less than 90 percent of the administered dose is excreted in the urine, on the premise that a deficient person will retain iodine in the tissues, rather than excrete it in the urine. According to the literature of a laboratory that offers it, 92-98 percent of patients who have taken the iodine-load test were found to be deficient in iodine.
According to Gaby, “the validity of the test depends on the assumption that the average person can absorb at least 90 percent of a 50-mg dose. It may be that people are failing to excrete 90 percent of the iodine in the urine not because their tissues are soaking it up, but because a lot of the iodine is coming out in the feces. There is no reason to assume that a 50-mg dose of iodine, which is at least 250 times the typical daily intake, can be almost completely absorbed by the average person. While this issue has not apparently been studied in humans, cows fed supraphysiological doses of iodine (72 to 161 mg per day) excreted approximately 50 percent of the administered dose in the feces.”
Gaby expressed concerns about iodine toxicity: “Fairly modest increases in iodine intake have been reported to cause thyroid dysfunction, particularly hypothyroidism. In a study of 33 Japanese patients with hypothyroidism, the median serum TSH level decreased from 21.9 mU/L to 5.3 mU/L (indicating an improvement in the hypothyroidism), and one-third became euthyroid, when the patients stopped eating seaweed and other high-iodine foods for 1-2 months. In a survey of 3,300 children aged 6-12 years from five continents, thyroid glands were twice as large in children with high dietary iodine intake (about 750 mcg per day), compared with children with more normal iodine intake. While the significance of that finding is not clear, it suggests the possibility of iodine-induced goiter. In addition, there is epidemiological evidence that populations with ‘sufficient’ or ‘high normal’ dietary iodine intake have a higher prevalence of autoimmune thyroiditis, compared with populations with deficient iodine intake. In a study of children in a mountainous area of Greece with a high prevalence of goiter, public-health measures taken to eliminate iodine deficiency were followed by a three-fold increase in the prevalence of autoimmune thyroiditis. In addition, modest increases in dietary iodine have been suspected to cause hyperthyroidism in some people, an effect that is known to occur with larger doses of iodine.
“Other well-known side effects of excessive iodine intake include acne, headaches, allergic reactions, metallic taste in the mouth and parotid gland swelling. While the doses of iodine reported to cause those side effects have often been higher than those currently being recommended, some people appear to be especially sensitive to the adverse effects of iodine.” Gaby concludes: “The possibility that high-dose iodine/iodide can relieve certain common conditions is intriguing. Considering the positive anecdotal reports, an empirical trial of iodine/iodide therapy, based on the clinical picture, seems reasonable. The case has not been made, however, that the average person should markedly increase his or her iodine intake in an attempt to saturate the tissues with iodine. Nor has the case been made that the iodine-load test can provide reliable guidance regarding the need for iodine therapy. Thyroid function should be monitored in patients receiving more than 1 mg of iodine per day.”
Subsequent counter arguments by Drs Abraham and Brownstein and rebuttals by Dr. Gaby focused on the amount of iodine in the Japanese diet and the safety of ingesting large amounts. An important point made by Abraham and Brownstein is that the requirement for iodine depends on the goitrogen load. Bromine, now very prevelant in the food supply, is a goitrogen, and may increase our need for iodine. They also claim that many of the toxic effects reported in the literature were due to radioactive forms of iodine. Finally, they dispute the assertion that the values of iodine in seaweed consumed by the Japanese were computed in dry weight. “The average daily intake of iodine by mainland Japanese in 1963 was 13.8 mg, based on information supplied by the Japanese Ministry of Health, which used only dry weight in their calculations, confirmed by a phone interview of one of us (GEA) on June 21, 2005, with officials of this organization.”26
Abrahams and Brownstein also defended the urine test for iodine loading, noting studies showing that organic iodine is not excreted in the feces. They also cited their own clinical experience. “Our experience at the Center for Holistic Medicine has shown that patients with the lowest urinary iodide levels on the loading tests are often the most ill. Many of these patients with very low urine iodide levels following the loading test have severe illnesses such as breast cancer, thyroid cancer or autoimmune thyroid disorders. All of these conditions have been shown in the literature to be associated with iodine deficiency. Positive clinical results were seen in most of these patients after supplementation of orthoiodosupplementation within the range of 6.25-50 mg of iodine/iodide (1/2 to 4 tablets of Lugol in tablet form).”27
In response, Gaby noted that “all but one of the references I cited discussed the adverse effects of inorganic iodine” and that while Dr. Lugol did use high doses of his combination iodine/potassium iodide compound, “they were recommended primarily to treat infections (iodine is a broad-spectrum antimicrobial agent) and hyperthyroidism, not as routine nutritional support for the average person.” Finally, he notes a review article, published in 2000, in which the authors state that in the 1920s and 1930s, when potassium iodide (KI) was widely used, many patients died of KI-induced side effects, particularly pulmonary edema and associated heart failure.28
Conclusions
It is axiomatic that there are no uncomplicated issues in the field of diet and health – and the subject of iodine is no exception. What conclusions can we draw from these conflicting assertions about iodine, especially supplementation containing iodide?
Let’s start by looking at the RDI of 100-150 mcg iodine per day. Most would argue that this intake is too low. Yet it is in line with what Weston Price reports in primitive diets. In preliminary analyses, he found a range of 24-32 mcg daily for the northern American Indians and 131-175 daily for the Inuit.29 Apparently the Inuit of the far north do not eat seaweed.30 Unfortunately, Price did not carry out more extensive measurements, especially among those he reported to eat seaweed—the Gaelic peoples of the Outer Hebrides and the Andean Indians of Peru.
It appears to be very difficult to estimate the iodine intake in diets that contain seaweed. Based on the reported values in seaweed, some have claimed levels of 12 mg (12,000 mcg) in Japanese diets,31 leading Abraham and Brownstein to propose that “only mainland Japanese consume adequate amounts of iodine and that 99 percent of the world population are deficient in inorganic, non-radioactive iodine; that is, they have not reached whole body sufficiency for that essential element.”32
However, a published analysis of iodine intake in Japan found a range of 45-1921 mcg per day,33 and Weston Price found healthy peoples consuming iodine amounts in the lower end of this range. Furthermore, without seaweed, it would be very difficult to exceed 1,000 mcg per day, based on values found in typical traditional foods (see chart, page 47). For example, one meal of cod, one meal of shellfish including the 20 grams of the hepatopancreas, and one meal of mussels, plus additional meat, vegetables and legumes would supply about 1,000 mcg iodine; diets based on meat, even organ meats, would supply considerably less.
The late distinguished researcher Emmanual Cheraskin and his colleagues conducted a survey of reported total number of clinical symptoms and signs (as judged from the Cornell Medical Index Health Questionnaire) and correlated the findings with average iodine consumption. An intake of approximately 1,000 mcg per day correlated with the lowest number of reported symptoms, that is, the highest level of health.34
Abraham and Brownstein argue that the human iodine requirement is 1,500 mcg per day (1.5 mg) which is difficult to achieve without using seaweed, iodized salt or supplementation. They argue that because of widespread bromide and fluoride toxicity, most people today require between 5 and 50 mg per day, amounts only possible with supplementation; they do note that such supplementation should only be taken under the supervision of a physician to monitor iodine status.35
We cannot ignore the many reports of improved health using various types of iodine supplementation—whether through tincture of iodine on the skin, the atomidine protocol recommended by Edgar Cayce or use of iodine/potassium iodide compounds as proposed by Drs. Abraham and Brownstein. Increased exposure to goitrogenic mercury, bromides and fluoride compounds, and soy products ubiquitous in the food supply, coupled with declining levels of thyroid-supporting nutrients such as selenium and vitamin A in modern diets, may explain why some people need much higher levels of iodine than those found in traditional diets. Dr. Brownstein is to be credited with alerting the public to the dangers of bromides increasingly used in processed foods, sodas, vegetable oils, breads and even replacing iodine in teat washes for dairy cows, as well as in thousands of consumer products.
The Abraham protocol does carry a risk of adverse reactions and should be carried out under the supervision of a physician with experience in using it. As these physicians point out, consuming iodine in milligram doses should be coupled with a complete nutritional program that includes adequate amounts of selenium and magnesium, and, they claim, omega-3 fatty acids, and with careful supervision of detoxing reactions. According to Dr. Brownstein, chloride increases renal clearance of bromide and the use of salt or ammonium chloride shortens the time required for bromide detoxification. He recommends oral administration of sodium chloride (6-10 gm per day) or intravenous sodium chloride for increasing the renal clearance of bromide.31
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Commercial Vegetable Oils and the Thyroid Gland
Although Dr. Weston Price found healthy populations groups that consumed fairly low levels of iodine, studies indicate that in modern times, most people do best at the upper end of the scale, taking in around 1,000 mcg per day. Often overlooked in this discussion are the many factors in the modern diet that depress thyroid function and increase our need for iodine—not only exposure to halogens like fluroide, chloride and bromide, but also deficiencies in vitamin A, vitamin B6, selenium and magnesium. Reduced exposure to halogens and abundant intake of these key nutrients probably reduces our requirements for iodine.
Another modern dietary factor that interferes with thyroid function is the consumption of omega-6 fatty acids from commercial vegetable oils—by some estimates these omega-6 fatty acids contribute 20 percent of calories in “civilized” diets. As pointed out by Stephen Guyenet in his Whole Health Source blog, omega-6 fatty acids may suppress thyroid signaling. He cites studies showing that corn oil greatly suppresses the liver’s response to T4 when compared to lard, safflower oil suppresses the liver’s response to T3 when compared to beef tallow, and linoleic acid suppresses the response of brown fat and the liver to T3. The liver is one of the main sites of thyroid hormone-responsive heat production. In fact, in the 1970s researchers were considering omega-6 lineleic acid as a treatment for hyperthyroidism.
Thus it is likely that those who avoid commercial vegetable oils and minimize omega-6 consumption, while emphasizing intake of nutrient-dense animal fats like butter and cod liver oil, would have iodine requirements much lower than 1,000 mcg per day, and would be able to meet their iodine requirements with a diet of whole foods, especially one containing sea food.
