The Best Diet for Optimal Thyroid Function (webinar recording)

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

Video 1: Are Vegans at Risk for Iodine Deficiency?

Adequate dietary iodine is required for normal thyroid function. In fact, the two thyroid hormones are named after how many iodine atoms they contain: T3 and T4. Given that iodine is extensively stored in the thyroid gland itself, it’s not something you have to get every day, but your overall diet needs to have some good source. Unfortunately, the common sources aren’t particularly health-promoting: iodized salt and dairy foods (because iodine-based cleansers like betadine are used to sanitize the udders, which results in some iodine leaching into the milk). They also add iodine to cattle feed, and some commercial breads have iodine-containing food additives.

So, if you put people on a paleo-type diet, and cut out dairy and table salt, they can develop an iodine deficiency, even though they double their seafood intake, which can also be a source. What about those switching to diets centered around whole plant foods? They’re also cutting down on ice cream and Wonder Bread, and if they’re not eating anything from the sea––seaweed; sea vegetables—they can run into the same problem.

Her parents reported striving to feed her only the healthiest foods. The three-year-old only got plant-based, unsalted, unprocessed foods with no vitamin supplementation. Now, that could be deadly. With no vitamin B12, those on strictly plant-based diets can develop irreversible nerve damage, but in this case, a goiter arose first due to inadequate iodine intake.

Here’s another case of “veganism as a cause of iodine deficient hypothyroidism” in a toddler after weaning. Before weaning, he was fine, because his mother kept taking her prenatal vitamins, which luckily contained iodine.

Most vegetarians and vegans are apparently unaware of the importance of iodine in pregnancy, just as clueless as their omnivorous counterparts. The American Thyroid Association and the American Academy of Pediatrics have recommended that women even just planning on getting pregnant should ingest a daily supplement that contains 150 micrograms (mcg) of iodine, yet only 60 percent of prenatal vitamins marketed in the U.S. contain this essential mineral. So, in spite of the recommendations, about 40 percent lack it. Therefore, it is extremely important that pregnant and breastfeeding women read the labels to ensure that they are receiving an adequate amount.

Women of reproductive age have an average iodine level of 110 mcg/liter, which is fine for nonpregnant individuals, but we’d really like to see at least 150 mcg/liter in pregnancy. (It’s basically a 24-hour urine test, in which iodine sufficiency is defined as 100 mcg/liter of pee in nonpregnant adults, which your average vegan fails to reach in the largest study done to date, out of Boston.)

The recommended average daily intake is 150 mcg/day for most people, which you can get in like a cup and a half of cow’s milk. Sadly, plant-based milks are typically not fortified with iodine, averaging only about 3 mcg/cup. In the largest systematic study to date, although many plant-based milks are fortified with calcium, they only found just three of 47 fortified with iodine. Those that were had as much as cow’s milk, but those that weren’t fell short.

Plant-based milk companies brag about enriching their milks with calcium, and often vitamin B12, vitamin D, and vitamin A, but only rarely are attempts made to match the iodine content. The only reason cow’s milk has so much is that they enrich the feed, or it comes dripping off the udders. So, why don’t plant-milk companies add iodine, too? I was told by a food scientist at Silk that my carrageenan video played a role in them switching to another thickener. Hopefully, they’ll see this video and consider adding iodine too, or some company will snatch at the market advantage opportunity.

The researchers conclude that individuals who consume plant-based milks not fortified with iodine may be at risk for iodine deficiency, unless they consume alternative dietary iodine sources, the healthiest of which is sea vegetables––which we’ll cover next.

Video 2: The Healthiest Natural Source of Iodine

Dairy milk supplies between a quarter and a half of the daily iodine requirement in the United States, though milk itself has little native iodine. The milk iodine content is mainly determined by factors like the application of iodine-containing teat disinfectants. The iodine residues in milk appear to originate mainly from the contamination of the teat surface. The teats are sprayed or dipped with betadine-type disinfectants, and the iodine just kind of leaches into the milk.

Too bad most of the plant-based milks on the market aren’t enriched with iodine, too. Fortified soy milk is probably the healthiest of the plant milks, but even if it was enriched with iodine, what about the effects of soy on thyroid function? It’s funny that when I searched the medical literature on soy and thyroid, this study popped up. A cost-effective way to train residents to do thyroid biopsies. Just stick the ultrasound probe right on top and go to town. It turns out that on ultrasound your thyroid gland looks a lot like tofu.

Anyways, the idea that soy may influence thyroid function originated over eight decades ago when marked thyroid enlargement was seen in rats fed raw soybeans, though the observation that people living in Asian countries have consumed soy foods for centuries with no perceptible thyrotoxic effects certainly suggests their safety. The bottom line is there does not seem to be a problem with people who have normal thyroid function. However, soy foods may inhibit the oral absorption of Synthroid, thyroid hormone replacement drugs, but so do all foods. That’s why we tell patients to take it on an empty stomach. But you also have to be getting enough iodine, so it may be particularly important for soy food consumers to make sure their intake of iodine is adequate.

What’s the best way to get iodine? For those who use table salt, make sure it’s iodized. Currently, only half of table salt sold contains iodine, and the salt used in processed foods is typically not iodized. Of course, ideally, we shouldn’t add any salt at all. Dietary salt is a public health hazard. Think this title is a little over the top? Dietary salt is the #1 dietary risk factor for death on the planet Earth, wiping out more than three million people a year—twice as bad as not eating your vegetables.

What’s the best source of iodine, then? Sea vegetables! You can get a little iodine here and there from a whole variety of foods, but the most concentrated source by far, with up to nearly 2,000 percent of your daily allowance in just a single gram (which is like the weight of a paperclip) of seaweed.

Given that iodine is extensively stored in the thyroid, it can be safely consumed intermittently, meaning you don’t have to get it every day, which makes seaweed use in a range of foods attractive, and occasional seaweed intake enough to ensure iodine sufficiency. However, some seaweed should be used with caution due to its overly high iodine content, like kelp. Too much iodine can cause hyperthyroidism, a hyperactive thyroid gland. A woman presented with a racing heartbeat, insomnia, anxiety, and weight loss thanks to taking just two tablets a day containing kelp.

In my last video, I noted how the average urinary iodine level of vegans was less than the ideal levels, but there was one kelp-eating vegan with a urinary concentration over 9,000 mcg/liter. Adequate intake is when you’re peeing out 100-199 mcg/liter. Excessive iodine intake is when you break 300 mcg/liter, and 9,437 mcg/liter is way too much.

The recommended average daily intake is 150 mcg/day for non-pregnant, non-breastfeeding adults, and we may want to stay below 600 mcg/day on a day-to-day basis, whereas a tablespoon of kelp may contain 2,000 mcg. I’d stay away from kelp because it has too much, and stay away from hijiki because it contains too much arsenic. Here’s how much of common seaweed preparations should give you an approximate daily allowance: two nori sheets, which you can literally just nibble on them as snacks like I do; one teaspoon of dulse flakes, which you can just sprinkle on anything; one teaspoon of dried arame, which is great to add to soups; or one tablespoon of seaweed salad.

If iodine is concentrated in marine foods, this raises the question of how early hominins living in continental areas could have met their iodine requirements. Here’s what bonobos do, perhaps our closest relatives. During swamp visits, they all forage aquatic herbs.

Video 3: The Best Diet for Hypothyroidism and Hyperthyroidism

There are several autoimmune diseases that affect the thyroid gland, the most common being Graves’ disease and Hashimoto’s thyroiditis. Graves’ disease results in hyperthyroidism, an overactive thyroid gland. Though slaughterhouses are supposed to remove thyroid glands, should some neck meat slip in, you can suffer a similar syndrome, called hamburger thyrotoxicosis. But that’s not from your body making too much thyroid hormone, but your body eating too much thyroid hormone. Graves’ disease is much more common, and meat-free diets may be able to help with both, as plant-based diets may be associated with a low prevalence of autoimmune disease in general––as observed, for example, in rural sub-Saharan Africa. Maybe it’s because plants are packed with antioxidants, which are possible protective factors against autoimmune diseases. Maybe it’s because plants are packed with anti-inflammatory compounds. After all, a whole food plant-based diet is basically synonymous with an anti-inflammatory diet. But you don’t know, until you put it to the test.

It turns out the exclusion of all animal foods was associated with half the prevalence of hyperthyroidism compared with omnivorous diets. Lacto-ovo-vegetarian and fish-only diets were associated with intermediate protection, but a 52-percent lower odds of hyperthyroidism among those eating strictly plant-based diets.

This apparent protection may be due to the exclusion of animal foods, the benefits of plant foods, or both. Animal foods––like meat, eggs, and dairy products––may contain high estrogen concentrations, for example, which have been linked to autoimmunity in preclinical studies. Or, the decrease in animal protein may downregulate IGF-1, which is not just a cancer-promoting growth hormone, but may play a role in autoimmune diseases as well. Or, it could be the good stuff in plants that may protect cells––like the polyphenol phytochemicals, such as flavonoids found in plant foods. Maybe it’s the environmental toxins that build up in the food chain. For example, fish contaminated with industrial pollutants, like PCBs, are associated with an increased frequency of thyroid disorders.

Okay, but what about the other autoimmune thyroid disease, Hashimoto’s thyroiditis, which, assuming you’re getting enough iodine, is the primary cause of hypothyroidism, an underactive thyroid gland. Graves’ disease wasn’t the only autoimmune disorder that was rare or virtually unknown among those living in rural sub-Saharan Africa eating near-vegan diets. They also appeared to have less Hashimoto’s.

There is evidence that those with Hashimoto’s have compromised antioxidant status, but we don’t know if it’s cause or effect. But if you look at the dietary factors associated with blood levels of autoimmune anti-thyroid antibodies, animal fats seem to be associated with higher levels, whereas vegetables and other plant foods are associated with lower levels. So again, anti-inflammatory diets may be useful. It’s no surprise, as Hashimoto’s is an inflammatory disease—that’s what thyroiditis means: inflammation of the thyroid gland.

Another possibility is the reduction in methionine intake, an amino acid concentrated in animal protein––thought to be one reason why the consumption of whole plant foods is likely to have a favorable influence on longevity, through decreasing the risk of cancer, heart disease, and diabetes. And methionine restriction improves thyroid function in mice, but it has yet to be put to the test for Hashimoto’s in humans.

If you compare the poop of patients with Hashimoto’s to controls, the condition appears to be related to a clear reduction in the concentration of Prevotella species. Prevotella are good fiber-eating bugs known to enhance anti-inflammatory activities. Decreased Prevotella levels are also something you see in other autoimmune conditions, such as multiple sclerosis and type 1 diabetes. How do you get more Prevotella? Eat more plants. But put a vegetarian on a diet of meat, eggs, and dairy, and within as few as four days, you can drive down levels. So, one would expect those eating plant-based diets to have less Hashimoto’s, but in a previous video I expressed concern about insufficient iodine intake, which could also lead to hypothyroidism. So, which is it? Let’s find out.

Vegan diets tended to be associated with lower, not higher, risk of hypothyroid disease. Why the word “tended”? Because the associated protection against hypothyroidism incidence and prevalence studies did not reach statistical significance. It wasn’t just because they were slimmer. The lower risk existed even after controlling for body weight; so, they think maybe it’s because animal products may induce inflammation. The question I have is: If you have someone who already has Hashimoto’s, what happens if you change their diet? That’s exactly what I’ll explore next.

Video 4: Diet for Hypothyroidism: A Natural Treatment for Hashimoto’s Disease

Autoimmune thyroiditis, also known as Hashimoto’s disease, is an organ-specific autoimmune disorder where your body attacks your own thyroid gland, often leading to hypothyroidism due to destruction and scarring of the gland itself. We know there’s a genetic component, since identical twins are more likely to share the disease than fraternal twins. However, even with identical twins, the concordance rate was only about 50 percent––meaning even if your identical twin with basically the exact same DNA as you has the disease, there’s only like a flip of a coin’s chance you’ll get it, emphasizing that important factors other than your genes play a role in the development of the disease. Genes load the gun, but environment may pull the trigger.

More than 90 chemicals have been noted disrupting hormonal balance or thyroid function; however, only a few such pollutants show evidence that they contribute to autoimmune thyroid disease. These include polyaromatic hydrocarbons, which smokers get a lot from their cigarettes, but in nonsmokers, exposure comes almost entirely from food. Polycyclic aromatic hydrocarbons are primarily formed when muscle meats, such as beef, pork, fish, or chicken, are cooked by high temperature methods, such as grilling. PBBs are a type of flame-retardant chemical no longer manufactured in the U.S., but still found in the aquatic food chain. PCBs are used in a number of industrial processes, and end up in people’s bodies largely through the consumption of fish as well, but also other meat and eggs.

So, one might suspect those eating plant-based diets would have lower rates of hypothyroidism, and indeed, despite their lower iodine intake, vegan diets tended to be protective. But they’ve never been put to the test in an interventional trial. A modification of the Paleolithic diet has been tried in Hashimoto’s patients, but didn’t appear to improve thyroid function.

What did, though, was Nigella Sativa. That name should sound familiar to anyone who’s read my latest book How Not to Diet, or watched my latest live presentation Evidence-Based Weight Loss. Nigella Sativa is the sciency name for black cumin, which is just a simple spice, but it is also used for a variety of medicinal purposes.

In this study, a randomized, double-blind placebo-controlled trial of eight weeks of a half teaspoon of powdered black cumin a day in Hashimoto’s patients. Not only was there a significant reduction in body weight, which is why I profiled it in my book, it also significantly reduced thyroid stimulating hormone, a sign that thyroid function was improving. It even lowered the level of autoimmune anti-thyroid antibodies, as well as increasing blood levels of thyroid hormone T3 in these Hashimoto’s patients. In addition, there was a significant drop in Interleukin 23, a proinflammatory cell signal thought to help promote the autoimmune inflammation of the thyroid, so further confirming the anti-inflammatory nature of the plant. And what were the side effects? A 17 percent drop in LDL bad cholesterol.

Given the fact that patients with Hashimoto’s may be at particularly high risk of developing heart disease, this is exactly the kind of side effect we’d want. “Considering these health-promoting effects of black cumin, it can be considered as a therapeutic approach in management of Hashimoto-related metabolic abnormalities.”

A similar trial failed to find a benefit, though. Same dose, same time frame, but no significant changes in thyroid function. In contrast with the last study, though, they were not all Hashimoto’s patients, but rather hypothyroid for any reason, and that may have diluted the results. And it’s possible that telling patients to take the black cumin doses with their thyroid hormone replacement therapy may have interfered with its absorption, similar to other foods and drugs––which is why patients are normally told to take it on an empty stomach. Since there are no downsides—it’s just a simple spice—I figure, why not give it a try? The worst that can happen is you’ll have tastier food.

• Leung AM, Lamar A, He X, Braverman LE, Pearce EN. Iodine status and thyroid function of Boston-area vegetarians and vegans. J Clin Endocrinol Metab. 2011;96(8):E1303-7.
• Combet E. 42 - Iodine status, thyroid function, and vegetarianism. In: Mariotti F, ed. Vegetarian and Plant-Based Diets in Health and Disease Prevention. Academic Press. 2017:769-90.
• Booms S, Hill E, Kulhanek L, Vredeveld J, Gregg B. Iodine deficiency and hypothyroidism from voluntary diet restrictions in the US: Case reports. Pediatrics. 2016;137(6):e20154003.
• Manousou S, Stål M, Larsson C, et al. A Paleolithic-type diet results in iodine deficiency: A 2-year randomized trial in postmenopausal obese women. Eur J Clin Nutr. 2018;72(1):124-9.
• Hunter JD, Crudo DF. Unintended consequences of restrictive diets: Two case reports and a review of orthorexia. Clin Pediatr (Phila). 2018;57(14):1693-5.
• Yeliosof O, Silverman LA. Veganism as a cause of iodine deficient hypothyroidism. J Pediatr Endocrinol Metab. 2018;31(1):91-4.
• Patel A, et al. Iodine deficiency: Iodine content is low or absent in some US multivitamin and prenatal vitamin brands. Clin Thyroidol. 2019;12(5):3-4.
• Herrick KA, Perrine CG, Aoki Y, Caldwell KL. Iodine status and consumption of key iodine sources in the U.S. population with special attention to reproductive age women. Nutrients. 2018;10(7):874.
• Ma W, He X, Braverman L. Iodine content in milk alternatives. Thyroid. 2016;26(9):1308-10.
• Bath SC, Hill S, Infante HG, Elghul S, Nezianya CJ, Rayman MP. Iodine concentration of milk-alternative drinks available in the UK in comparison with cows' milk. Br J Nutr. 2017;118(7):525-32.
• van der Reijden OL, Zimmermann MB, Galetti V. Iodine in dairy milk: Sources, concentrations and importance to human health. Best Pract Res Clin Endocrinol Metab. 2017;31(4):385-95.
• Flachowsky G, Franke K, Meyer U, Leiterer M, Schöne F. Influencing factors on iodine content of cow milk. Eur J Nutr. 2014;53(2):351-65.
• Castro SI, Berthiaume R, Robichaud A, Lacasse P. Effects of iodine intake and teat-dipping practices on milk iodine concentrations in dairy cows. J Dairy Sci. 2012;95(1):213-20.
• Ma W, He X, Braverman L. Iodine content in milk alternatives. Thyroid. 2016;26(9):1308-10.
• Ferruzzi MG, Tanprasertsuk J, Kris-Etherton P, Weaver CM, Johnson EJ. Perspective: The role of beverages as a source of nutrients and phytonutrients. Adv Nutr. 2020;11(3):507-23.
• Messina M, Redmond G. Effects of soy protein and soybean isoflavones on thyroid function in healthy adults and hypothyroid patients: A review of the relevant literature. Thyroid. 2006;16(3):249-58.
• Zhang YF, Li H, Wang XM. Technical Report: A cost-effective, easily available tofu model for training residents in ultrasound-guided fine needle thyroid nodule targeting punctures. Korean J Radiol. 2019;20(1):166-70.
• Tonstad S, Jaceldo-Siegl K, Messina M, Haddad E, Fraser GE. The association between soya consumption and serum thyroid-stimulating hormone concentrations in the Adventist Health Study-2. Public Health Nutr. 2016;19(8):1464-70.
• Liwanpo L, Hershman JM. Conditions and drugs interfering with thyroxine absorption. Best Pract Res Clin Endocrinol Metab. 2009;23(6):781-92.
• Patel A, et al. Iodine deficiency: Iodine content is low or absent in some US multivitamin and prenatal vitamin brands. Clin Thyroidol. 2019;12(5):3-4.
• Neal B. Dietary salt is a public health hazard that requires vigorous attack. Can J Cardiol. 2014;30(5):502-6.
• Shaldon S, Vienken J. Salt, the neglected silent killer. Semin Dial. 2009;22(3):264-6.
• GBD 2017 Diet Collaborators. Health effects of dietary risks in 195 countries, 1990-2017: A systematic analysis for the Global Burden of Disease Study 2017. Lancet. 2019;393(10184):1958-72.
• Choudhry H, Nasrullah M. Iodine consumption and cognitive performance: Confirmation of adequate consumption. Food Sci Nutr. 2018;6(6):1341-51.
• Combet E. 42 - Iodine status, thyroid function, and vegetarianism. In: Mariotti F, ed. Vegetarian and Plant-Based Diets in Health and Disease Prevention. Academic Press; 2017:769-90.
• Gherbon A, Frandes M, Lungeanu D, Nicula M, Timar R. Transient Hyperthyroidism following the ingestion of complementary medications containing kelp seaweed: A case-report. Medicine (Baltimore). 2019;98(37):e17058.
• Leung AM, Lamar A, He X, Braverman LE, Pearce EN. Iodine status and thyroid function of Boston-area vegetarians and vegans. J Clin Endocrinol Metab. 2011;96(8):E1303-7.
• Herrick KA, Perrine CG, Aoki Y, Caldwell KL. Iodine status and consumption of key iodine sources in the U.S. population with special attention to reproductive age women. Nutrients. 2018;10(7):874.
• Institute of Medicine. Dietary Reference Intakes: The essential guide to nutrient requirements. Washington, DC: The National Academies Press; 2006.
• European Food Safety Authority (EFSA). Overview on tolerable upper intake levels as derived by the Scientific Committee on Food (SCF) and the EFSA Panel on dietetic products, nutrition and allergies (NDA). Parma, Italy: EFSA. 2018:1-4.
• Teas J, Pino S, Critchley A, Braverman LE. Variability of iodine content in common commercially available edible seaweeds. Thyroid. 2004;14(10):836-41.
• Hohmann G, Ortmann S, Remer T, Fruth B. Fishing for iodine: What aquatic foraging by bonobos tells us about human evolution. BMC Zool. 2019;4:5.
• Merrill SJ, Minucci SB. Thyroid autoimmunity: an interplay of factors. Vitam Horm. 2018;106:129-45.
• 53 FR 45890, Nov. 15, 1988.
• Wartique L, Pothen L, Pirson N, Hermans MP, Lambert M, Yildiz H. An unusual cause of epidemic thyrotoxicosis. Acta Clin Belg. 2017;72(6):451-3.
• Tonstad S, Nathan E, Oda K, Fraser GE. Prevalence of hyperthyroidism according to type of vegetarian diet. Public Health Nutr. 2015;18(8):1482-7.
• Bodai BI, Nakata TE, Wong WT, et al. Lifestyle Medicine: A brief review of its dramatic impact on health and survival. Perm J. 2018;22:17-25.
• Langer P, Kočan A, Tajtakovác M, et al. Fish from industrially polluted freshwater as the main source of organochlorinated pollutants and increased frequency of thyroid disorders and dysglycemia. Chemosphere. 2007;67(9):S379-85.
• Ates I, Yilmaz FM, Altay M, Yilmaz N, Berker D, Güler S. The relationship between oxidative stress and autoimmunity in Hashimoto's thyroiditis. Eur J Endocrinol. 2015;173(6):791-9.
• Matana A, Torlak V, Brdar D, et al. Dietary factors associated with plasma thyroid peroxidase and thyroglobulin antibodies. Nutrients. 2017;9(11):1186.
• Caturegli P, De Remigis A, Rose NR. Hashimoto thyroiditis: clinical and diagnostic criteria. Autoimmun Rev. 2014;13(4-5):391-7.
• Yang Y, Zhang J, Wu G, et al. Dietary methionine restriction regulated energy and protein homeostasis by improving thyroid function in high fat diet mice. Food Funct. 2018;9:3718-31.
• Virili C, Fallahi P, Antonelli A, Benvenga S, Centanni M. Gut microbiota and Hashimoto's thyroiditis. Rev Endocr Metab Disord. 2018;19(4):293-300.
• Zhao F, Feng J, Li J, et al. Alterations of the gut microbiota in Hashimoto's Thyroiditis patients. Thyroid. 2018;28(2):175-86.
• Ishaq HM, Mohammad, IS, Guo H, et al. Molecular estimation of alteration in intestinal microbial composition in Hashimoto’s thyroiditis patients. Biomed Pharmacother. 2017;95:865-74.
• David LA, Maurice CF, Carmody RN, et al. Diet rapidly and reproducibly alters the human gut microbiome. Nature. 2014;505(7484):559-63.
• David LA, Maurice CF, Carmody RN, et al. Diet rapidly and reproducibly alters the human gut microbiome. Nature. 2014;505(7484):559-63.
• Burek CL, Talor MV. Environmental triggers of autoimmune thyroiditis. J Autoimmun. 2009;33(3-4):183-9.
• Tonstad S, Nathan E, Oda K, Fraser G. Vegan diets and hypothyroidism. Nutrients. 2013;5(11):4642-52.
• Burek CL, Talor MV. Environmental triggers of autoimmune thyroiditis. J Autoimmun. 2009;33(3-4):183-9.
• Scheepers PT, Jongeneelen FJ. Smoking and dietary intake of polycyclic aromatic hydrocarbons as sources of interindividual variability in the baseline excretion of 1-hydroxypyrene in urine. Int Arch Occup Environ Health. 1994;66(1):55-65.
• Punnen S, Hardin J, Cheng I, Klein EA, Witte JS. Impact of meat consumption, preparation, and mutagens on aggressive prostate cancer. PLoS One. 2011;6(11):e27711.
• Headrick ML, Hollinger K, Lovell RA, Matheson JC. PBBs, PCBs, and dioxins in food animals, their public health implications. In: Tollefson L, ed. Veterinary Clinics of North America: Food Animal Practice. Vol 4. W. B. Saunders Company; 1999:109-31.
• Weber R, Herold C, Hollert H, Kamphues J, Blepp M, Ballschmiter K. Reviewing the relevance of dioxin and PCB sources for food from animal origin and the need for their inventory, control and management. Environ Sci Eur. 2018;30(1):42.
• Tonstad S, Nathan E, Oda K, Fraser G. Vegan diets and hypothyroidism. Nutrients. 2013;5(11):4642-52.
• Abbott RD, Sadowski A, Alt AG. Efficacy of the Autoimmune Protocol Diet as part of a multi-disciplinary, supported lifestyle intervention for Hashimoto's thyroiditis. Cureus. 2019;11(4):e4556.
• Tajmiri S, Farhangic MA, Dehghan P. Nigella Sativa treatment and serum concentrations of thyroid hormones, transforming growth factor β (TGF-β) and interleukin 23 (IL-23) in patients with Hashimoto’s Thyroiditis. Eur J Integr Med. 2016;8(4):576-80.
• Farhangi MA, Dehghan P, Tajmiri S. Powdered black cumin seeds strongly improves serum lipids, atherogenic index of plasma and modulates anthropometric features in patients with Hashimoto’s thyroiditis. Lipids Health Dis. 2018;17:59.
• Chen WH, Chen YK, Lin CL, Yeh JH, Kao CH. Hashimoto's thyroiditis, risk of coronary heart disease, and L-thyroxine treatment: a nationwide cohort study. J Clin Endocrinol Metab. 2015;100(1):109-14.
• Tekieh MF, Esfahanian F, Emadi F, Gholami M, Emaratkar E. Effect of Nigella sativa on thyroid function in patients with hypothyroidism treated with levothyroxine: A triple-blind randomized controlled trial. Medical Science. 2019;23(98):606-14.
• Liwanpo L, Hershman JM. Conditions and drugs interfering with thyroxine absorption. Best Pract Res Clin Endocrinol Metab. 2009;23(6):781-92.

• animal products
• anti-inflammatory
• autoimmune diseases
• beef
• black cumin
• chicken
• cholesterol
• eggs
• fish
• hormones
• LDL cholesterol
• low-carb diets
• meat
• paleolithic diets
• Plant-Based Diets
• polycyclic aromatic hydrocarbons
• pork
• thyroid health
• vegans
• vegetarians