As someone with a thyroid condition, I have a personal interest in what research says about potential goitrogenic effects of millets consumed as food. This issue has only come up a couple of times on Collab,/1/2 and generally is not a wide concern outside of particular thyroid conditions or dietary insufficiency, but it is useful to be aware of our state of knowledge on the subject. So, here are two very recent items, followed by a few personal observations: 1. "Millets for Thyroid: Safe Choices, What to Avoid (2026)" https://www.orggu.com/blog/millets-for-thyroid This is a "guide" to millets from the point of view of thyroid health, produced by an Indian company, Orggu, which mentions as sources National Institute of Nutrition (NIN, Hyderabad, India), Indian Council of Medical Research (ICMR), and USDA FoodData Central. It meritsmention for its treatment of millets individually and for distinguishing between the two main and opposite types of thyroid conditions (over vs under production of thyroid hormones). However, it does not mention fonio or teff (not to surprising, given that Orggu operates only in India), nor does it mention proso millet (which is surprising, given that it is grown and consumed in India). Overall, its discussion is more detailed and nuanced than most other similar webpages I have seen. This is not to recommend it unconditionally, which I'm not qualified to do anyway. but if you're unfamiliar with this issue, it seems like a useful starting point. Millets covered: sorghum; pearl millet; finger millet; foxtail millet; little millet; kodo millet; barnyard millet (species not indicated); and browntop millet. 2. Onipe, O. O., Udeh, H. O., & Gwata, E. T. (2026). "Goitrogens in millets: occurrence, impact on product development and mitigation strategies." International Journal of Food Properties, 29(1). https://doi.org/10.1080/10942912.2026.2629050 This review article covers: sorghum; pearl millet; finger millet; foxtail millet; proso millet; little millet; kodo millet; barnyard millet (Echinochloa crus-galli and E. colona are mentioned, rather than E. esculenta and E. frumentaea); and fonio. ABSTRACT: "Goiter is a health disorder characterized by an enlarged thyroid gland, and it has been associated with iodine deficiency, which can be exacerbated by the ingestion of substances that impair iodine uptake (goitrogens). Millets have been associated with thyroid dysfunctions due to presence of goitrogens. Pearl millet (Pennisetum glaucum), finger millet (Eleusine coracana), and fonio (Digitaria exilis Stapf) contain appreciable amounts of goitrogens, thiocyanates and flavonoids, that can obstruct iodine metabolism in the thyroid. The concentration of thiocyanate and C-glycosyl flavones in finger millet ranged from 31 to 43 mg/kg, and from 15 to 541 and up to 350 mg/kg in pearl millet and fonio contain, respectively. This review consolidates growing knowledge about the occurrence, metabolic pathways, and dietary consequences of goitrogens in millets. The biochemical routes through which goitrogens inhibit the thyroid hormone peroxidase are discussed. The interplay of environmental and varietal and agricultural methods on the goitrogenic profile of minor millets is also clarified. The influence of processing on the breakdown of goitrogens is also discussed. The review findings indicate that employing a dual approach, heat and mechanical processing, reduces goitrogenicity in millets; nevertheless, in certain instances, such as fermentation and sprouting were found to have variable effect, with several studies indicating either stable or increased goitrogen levels. The study shows that cooking or boiling and decortication are the most effective methods to reduce goitrogens in millets." I found it a useful discussion that touched on many points. If you first looked at the webpage linked above (#1), this article gives more depth and explanation. If I were to make one editorial suggestion, it would be to be clearer on the set of milllets discussed at various points. For example the abstract mentions fonio but not sorghum, but a later list has the latter but not the former, even though similar issues were raised for both. And there was one discussion under "Boiling" of red and brown millet varieties, but it wasn't clear whether one millet or a common feature of several were described. Also, the brief discussion of the effect of soaking, which appears under the subheading of "Germination" might have its own subheading, or alternatively the subheading could include both words, to facilitate findng, since soaking is a separate practice used for many grains. Altogether, it is worth reading if you want more background on this topic. Some comments: * In general, it seems that the major millets - sorghum, pearl millet, and sometimes finger millet/3 - have higher content of goitrogenic compounds * The minor or small millets - those with hard husks or shells - seem to have less goitrogenic compounds. * Fonio, however, seems to have higher levels * Proso is not given any attention in #1, and is mentioned only once without discussion of its goitrogenic content in #2. One other site compares it to other minor millets in this regard: https://milletmatters.com/blogs/blogs/which-millet-is-good-for-thyroid-a-com... * Teff, as indicated above, and for that matter adlay on the other end of the size spectrum * Goitrogens are present in a range of foods, including some vegetables commonly sold and consumed in North America * Goitrogens are part of a larger category of what are called antinutrients, which also includes phytates (phytic acid), which are a different compoud found in whole grains (this woud be a separate discussion) * It might be helpful to have a NAMA explainer on this topic for a broad audience that improves on those discussed above (for instance bringing proso into it) - unless there's already one that we could point to * None of this is intended to raise unwarrented concerns about consumption of millets, which overall have many health and nutritional advantages. Fwiw, I consume a range of millets as part of a diverse diet, but have not experienced any adverse issues despite my thyroid issue.. Don Osborn, PhD (East Lansing, MI, US) North American Millets Alliance Notes: 1. "Supposed downsides of millets as food" 29 May 2023 https://lists.millets2023.space/archives/list/collab@lists.millets2023.space... 2. "Goitrogen issue again - pearl millet & fonio," 30 Aug 2024 https://lists.millets2023.space/archives/list/collab@lists.millets2023.space... 3. The topic of the major/minor (small) millets and the place of finger millet is one for another time.