Goitrogens in food and water

Elucidating the role of phytocompounds from Brassica oleracea var. italic (Broccoli) on hyperthyroidism: an in-silico approach

Thyroid hormone (TH) plays a crucial role in regulating the metabolism in every cell and all organs in of the human body. TH also control the rate of calorie burning, body weight, and function of the heartbeat. Therefore, the aim of the present study is to investigate the role of phytocompounds from Brassica oleracea var. italic (Broccoli) against irregularities of TH biosynthesis (hyperthyroidism) through in silico molecular modelling. Initially, the genetic network was built with graph theoretical network analysis to find the right target to control excessive TH production. Based on the network analysis, the three-dimensional crystal structure of the mammalian enzyme lactoperoxidase (PDB id: 5ff1) was retrieved from the protein data bank (PDB), and the active site was predicted using BIOVIA Discovery studio. Sixty-three phytocompounds were selected from the IMPPAT database and other literature. Selected sixty-six phytocompounds were docked against lactoperoxidase enzyme and compared with the standard drug methimazole. Based on the docking scores and binding energies, the top three compounds, namely brassicoside (- 10.00 kcal × mol-1), 24-methylene-25-methylcholesterol (- 9.50 kcal × mol-1), 5-dehydroavenasterol (- 9.40 kcal × mol-1) along with standard drug methimazole (- 4.10 kcal × mol-1) were selected for further ADMET and molecular dynamics simulation analysis. The top-scored compounds were for their properties such as ADMET, physicochemical and drug-likeness. The molecular dynamics simulation analyses proved the stability of lactoperoxidase-ligand complexes. The intermolecular interaction assessed by the dynamic conditions paved the way to discover the bioactive compounds brassicoside, 24-methylene-25-methylcholesterol, and 5-dehydroavenasterol prevent the excessive production of thyroid hormones.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-023-00180-2.

Prevalence and determinants of goitre among children of South Kordofan state, Sudan, 2021: an urgent need for effective implementation of universal salt iodisation

OBJECTIVE

This study aimed to determine the prevalence and determinants of goitre among children aged 6-12 years at South Kordofan state.

DESIGN

This was a cross-sectional facility-based study.

SETTING

The study was conducted in twenty villages of South Kordofan state during a medical mission.

PARTICIPANTS

All 575 school-age children (6-12 years) who attended the medical day were examined for clinical assessment of goitre.

RESULTS

The prevalence of goitre among children of South Kordofan was 42·8 % (grade 1: 15·7 %, grade 2: 27·1 %). Only 24·2 % of caregivers reported using iodised salt. Mothers working as farmers (OR: 3·209, CI 95 % 1·437, 7·167; P = 0·004) and children of Darforian tribes (OR: 21·799, CI 95 % 2·566, 185·226; P = 0·005) were found to be significantly associated with higher prevalence of goitre among children. This contrasts with children of African tribes, where they were found to have less goitre prevalence (OR: 0·432, CI 95 % 0·213, 0·875; P = 0·02). Iodised salt utilisation (OR = 0·523, CI 95 % 0·320, 0·854; P = 0·01) was found associated with a lower prevalence of goitre.

CONCLUSION

Even though National Iodine Deficiency Disorders control programs were initiated in Sudan more than 25 years ago, the prevalence of goitre among children in South Kordofan state was alarming (42·8 %). Efforts to improve access to iodised salt, increase utilisation and raise awareness are urgently needed.

Safety and toxicologic evaluation of Edible Pongamia Oil: A novel food ingredient

Edible Pongamia Oil (EPO) was evaluated in an acute oral toxicity study, GLP 14-Day and 90-Day repeated dose isocaloric dietary toxicity studies in rats, and in vitro Bacterial Reverse Mutation, and in vivo Mammalian Bone Marrow Chromosome Aberration genotoxicity studies for potential use as a food ingredient. In a non-GLP acute study, an LD₅₀ > 5000 mg/kg was determined. Subacute 14-day repeated dose dietary administration of 0, 5, 10 and 15% oil revealed no adverse changes in clinical pathology, liver histology, body weight or weight gain, food consumption or food efficiency. In a 90-day dietary study fed 0, 2.5, 5.0, 7.5 and 10.0%, no mortalities, clinical or ophthalmologic signs, body weight, body weight gain, food consumption, food efficiency or Functional Observational Battery/Motor Activity changes occurred with EPO consumption, nor were there any adverse changes in hematology, clinical chemistry, coagulation, urinalysis, or thyroid hormone values. There were no adverse macroscopic, estrus cycle, histopathologic or spermatogenesis findings, or absolute or relative organ weight changes related to administration of EPO. The No-Adverse-Effect-Level (NOAEL) was 10% in the diet, the highest dose tested, equivalent to 5163 (male) and 6469 (female) mg/kg/day in rats. No mutagenic or clastogenic genotoxic potential was reported.

Plant constituents and thyroid: A revision of the main phytochemicals that interfere with thyroid function

In the past few decades, there has been a lot of interest in plant constituents for their antioxidant, anti-inflammatory, anti-microbial and anti-proliferative properties. However, concerns have been raised on their potential toxic effects particularly when consumed at high dose. The anti-thyroid effects of some plant constituents have been known for some time. Indeed, epidemiological observations have shown the causal association between staple food based on brassicaceae or soybeans and the development of goiter and/or hypothyroidism. Herein, we review the main plant constituents that interfere with normal thyroid function such as cyanogenic glucosides, polyphenols, phenolic acids, and alkaloids. In detail, we summarize the in vitro and in vivo studies present in the literature, focusing on the compounds that are more abundant in foods or that are available as dietary supplements. We highlight the mechanism of action of these compounds on thyroid cells by giving a particular emphasis to the experimental studies that can be significant for human health. Furthermore, we reveal that the anti-thyroid effects of these plant constituents are clinically evident only when they are consumed in very large amounts or when their ingestion is associated with other conditions that impair thyroid function.

Neither soyfoods nor isoflavones warrant classification as endocrine disruptors: a technical review of the observational and clinical data

Soybeans are a rich source of isoflavones, which are classified as phytoestrogens. Despite numerous proposed benefits, isoflavones are often classified as endocrine disruptors, based primarily on animal studies. However, there are ample human data regarding the health effects of isoflavones. We conducted a technical review, systematically searching Medline, EMBASE, and the Cochrane Library (from inception through January 2021). We included clinical studies, observational studies, and systematic reviews and meta-analyses (SRMA) that examined the relationship between soy and/or isoflavone intake and endocrine-related endpoints. 417 reports (229 observational studies, 157 clinical studies and 32 SRMAs) met our eligibility criteria. The available evidence indicates that isoflavone intake does not adversely affect thyroid function. Adverse effects are also not seen on breast or endometrial tissue or estrogen levels in women, or testosterone or estrogen levels, or sperm or semen parameters in men. Although menstrual cycle length may be slightly increased, ovulation is not prevented. Limited insight could be gained about possible impacts of in utero isoflavone exposure, but the existing data are reassuring. Adverse effects of isoflavone intake were not identified in children, but limited research has been conducted. After extensive review, the evidence does not support classifying isoflavones as endocrine disruptors.

Incidence and prevalence of hyperthyroidism: a population-based study in the Piedmont Region, Italy

PURPOSE

Unrecognized and untreated hyperthyroidism leads to serious clinical complications with adverse outcomes for patients and increasing costs for the health care system. Hence, adequate knowledge of the epidemiological features of such condition is desirable to plan effective interventions. The aim of our study was to estimate incidence and prevalence of hyperthyroidism in the mildly iodine-deficient Italian Region of Piedmont.

METHODS

A retrospective cohort study was conducted using Administrative Health Databases of the Piedmont Region, Italy (2012-2018). Hyperthyroidism cases were defined as the subjects who had at least one of the following claims: (i) hospital discharge records with hyperthyroidism diagnosis code; (ii) exemption from co-payment for hyperthyroidism; (iii) prescription of one of the following medications: methimazole, propylthiouracil, or potassium perchlorate.

RESULTS

The overall prevalence was 756 per 100,000 inhabitants [95% CI 748-764], and the overall incidence was 81 per 100,000-person year [95% CI 80-82]. The prevalence and incidence increased with age and were two-fold higher among women than men. Women also showed two distinct peaks in incidence at the age of 30 and 50; after the age of 60, the trend became similar between sexes. With regard to the geographic distribution, an increasing gradient of incidence was observed from the northern to the south-western areas of the Region.

CONCLUSION

This is the first Italian study based on health databases to estimate the incidence and prevalence of hyperthyroidism in the general population. This approach can represent an inexpensive and simple method to monitor patterns of hyperthyroidism in iodine-deficient areas.

Excess iodine impairs spermatogenesis by inducing oxidative stress and perturbing the blood testis barrier

Approximately 2 billion people worldwide are susceptible to iodine deficiency. Iodine deficiency has largely been tackled by iodine fortification in salt; however indiscriminate use of iodine raises the risk of iodine toxicity. In this study, we aimed to investigate the molecular mechanisms underlying adverse effect of excess iodine on spermatogenesis. Sprague Dawley (SD) rats were orally administered with 0.7 mg potassium iodide (KI)/100 g Bw and 3.5 mg potassium iodide (KI)/100 g Bw for a period of 60 days. This resulted in significant loss of sperm count and motility. Molecular investigations provided evidence for the generation of oxidative stress with high SOD levels, reduced Nrf2, HO-1 and increased NF-kB and Follistatin. Further investigations showed increased apoptosis evidenced by reduced expression of anti-apoptotic (BCL-2, Survivin), increased expression of pro-apoptotic (Bid, Bax) markers, and increased expression of p53 and other modulators/effectors of apoptosis (cytochrome c, cleaved PARP, caspase3 and caspase9). Analysis of the blood testis barrier proteins showed reduced expression of tight junction (JAM-A, Tricellulin), ectoplasmic specialization (Integrin- β1), adherens junction (N-Cadherin, E-cadherin, β-catenin) proteins, and reduced expression of other junction protein coding genes (Claudin1, Claudin 5, Occludin, ZO-1, Testin, Fibronectin, CAR-F). Focal adhesion kinase (FAK) and key regulators of spermatogenesis (c-Kit receptor, androgen receptor) were also parallelly decreased. Further investigation showed reduced expression of germ cell proliferation and differentiation markers (PCNA, Cyclin D1, c-Kit, Cdk-4). These findings collectively explain the loss of spermatogenesis under excess iodine conditions. In conclusion, excess iodine causes loss of spermatogenesis by inducing oxidative stress and disrupting the blood testis barrier and cytoskeleton.

Lifetimes of the Aglycone Substrates of Specifier Proteins, the Autonomous Iron Enzymes That Dictate the Products of the Glucosinolate-Myrosinase Defense System in Brassica Plants

Specifier proteins (SPs) are components of the glucosinolate-myrosinase defense system found in plants of the order Brassicales (brassicas). Glucosinolates (GLSs) comprise at least 150 known S-(β-d-glucopyranosyl)thiohydroximate-O-sulfonate compounds, each with a distinguishing side chain linked to the central carbon. Following tissue injury, the enzyme myrosinase (MYR) promiscuously hydrolyzes the common thioglycosidic linkage of GLSs to produce unstable aglycone intermediates, which can readily undergo a Lossen-like rearrangement to the corresponding organoisothiocyanates. The known SPs share a common protein architecture but redirect the breakdown of aglycones to different stable products: epithionitrile (ESP), nitrile (NSP), or thiocyanate (TFP). The different effects of these products on brassica consumers motivate efforts to understand the defense response in chemical detail. Experimental analysis of SP mechanisms is challenged by the instability of the aglycones and would be facilitated by knowledge of their lifetimes. We developed a spectrophotometric method that we used to monitor the rearrangement reactions of the MYR-generated aglycones from nine GLSs, discovering that their half-lives (t_1/2) vary by a factor of more than 50, from <3 to 150 s (22 °C). The t_1/2 of the sinigrin-derived allyl aglycone (34 s), which can form the epithionitrile product (1-cyano-2,3-epithiopropane) in the presence of ESP, proved to be sufficient to enable spatial and temporal separation of the MYR and ESP reactions. The results confirm recent proposals that ESP is an autonomous iron-dependent enzyme that intercepts the unstable aglycone rather than a direct effector of MYR. Knowledge of aglycone lifetimes will enable elucidation of how the various SPs reroute aglycones to different products.

Monitoring and Evaluation of Thyroid Function Tests, Serum Electrolytes and Creatinine Levels Before and After 131I Therapy

Background:

Serum electrolytes, Creatinine, and thyroid profile play an important role in 131I treated patients of thyroid disorders.

Objectives:

To determine the effect of radioactive iodine (131I) on renal parameters, serum electrolytes and the correlation among TFT’S, creatinine, and chloride levels before and after I131 treatment in thyroid disorders.

Methods:

The study was performed on 55 patients of thyrotoxicosis with age ranging from 16-65 years (mean age= 41±14years and BMI=24.8±4.46). The significance of the differences between the results of 1st, 2nd, and 3rd-time serum analysis was assessed by paired Student's t-test. Association between parameters was assessed by Spearman correlation analysis.

Results:

40 patients were taking Carbimazole, and 15 were directly recommended for I131 therapy. Strongly significant variations were observed for TFT’S (T3=0.012, T4 =0.017, and TSH=0. 001) during the follow-up treatment. Before taking I131 (Serum analyzed at 1st time), there observed negative correlation of T3(r=-.46, p=0. 002) and TSH (r=-0.31, p=0.02) with creatinine, and positive correlation of TSH(r=0.29,p=0.02) with chloride. BMI was negatively correlated with potassium(r=-0.30, p=0.02). At the 2nd time (after stopping the Carbimazole), no correlation results were observed. Two months after oral administration of 131I, creatinine, and chloride level was significantly increased (p=0.000), (P=0. 03) respectively, but had no correlation with TFT’S.

Conclusion:

Our findings suggest that patients with goiter (diffused or toxic) have association of TFT’S and BMI with serum electrolytes and creatinine, 131I therapy is also associated with the increase in creatinine and chloride levels of patients leading to kidney problems.

Thyroid Function and Nutrient Status in the Athlete

Thyroid disease is common in the general population, especially in women, and also may be prevalent among athletes. Autoimmune disorders are the most common cause of thyroid disorders in countries with iodine-fortification programs; however, thyroid dysfunction can be brought on by nutritional factors, including insufficient energy intake and iodine, selenium, iron, and vitamin D deficiency. Additionally, strenuous exercise may be associated with transient alterations in thyroid hormones. While the development of thyroid related disorders has the potential to impact health and peak performance, typical clinical manifestations are highly variable, lack specificity, and are frequently confused with other health problems. The assessment process should focus on anthropometric changes, biochemical tests (thyroid panel), personal and family history, examination for appropriate signs and symptoms, and diet and environmental assessment that includes adequacy of energy, iodine, iron, selenium, and vitamin D intake/status along with excess stress and exposure to environmental contaminants and dietary goitrogens.

Source apportionment of micronutrients in the diets of Kilimanjaro,Tanzania and Counties of Western Kenya

Soil, water and food supply composition data have been combined to primarily estimate micronutrient intakes and subsequent risk of deficiencies in each of the regions studied by generating new data to supplement and update existing food balance sheets. These data capture environmental influences, such as soil chemistry and the drinking water sources to provide spatially resolved crop and drinking water composition data, where combined information is currently limited, to better inform intervention strategies to target micronutrient deficiencies. Approximately 1500 crop samples were analysed, representing 86 food items across 50 sites in Tanzania in 2013 and >230 sites in Western Kenya between 2014 and 2018. Samples were analysed by ICP-MS for 58 elements, with this paper focussing on calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), selenium (Se), iodine (I), zinc (Zn) and molybdenum (Mo). In general, micronutrient supply from food groups was higher from Kilimanjaro,Tanzania than Counties in Western Kenya, albeit from a smaller sample. For both countries leafy vegetable and vegetable food groups consistently contained higher median micronutrient concentrations compared to other plant based food groups. Overall, calculated deficiency rates were <1% for Cu and Mo and close to or >90% for Ca, Zn and I in both countries. For Mg, a slightly lower risk of deficiency was calculated for Tanzania at 0 to 1% across simplified soil classifications and for female/males, compared to 3 to 20% for Kenya. A significant difference was observed for Se, where a 3 to 28% risk of deficiency was calculated for Tanzania compared to 93 to 100% in Kenya. Overall, 11 soil predictor variables, including pH and organic matter accounted for a small proportion of the variance in the elemental concentration of food. Tanzanian drinking water presented several opportunities for delivering greater than 10% of the estimated average requirement (EAR) for micronutrients. For example, 1 to 56% of the EAR for I and up to 10% for Se or 37% for Zn could be contributed via drinking water.

Antinutrients in Plant-based Foods: A Review

Modern society has easy access to a vast informational database. The pursuit of sustainable green and healthy lifestyle leads to a series of food choices. Therefore, it is of importance to provide reliable, comprehensive and up-to-date information about food content including both nutritional and antinutritional elements.

Nutrients are associated with positive effects on human health. Antinutrients, on the other hand, are far less popular for the contemporary man. They are highly bioactive, capable of deleterious effects as well as some beneficial health effects in man, and vastly available in plant-based foods. These compounds are of natural or synthetic origin, interfere with the absorption of nutrients, and can be responsible for some mischievous effects related to the nutrient absorption. Some of the common symptoms exhibited by a large amount of antinutrients in the body can be nausea, bloating, headaches, rashes, nutritional deficiencies, etc. Phytates, oxalates, and lectins are few of the well-known antinutrients.

Science has acknowledged several ways in order to alter the negative influence antinutrients exhibiting on human health. Mechanical, thermal and biochemical approaches act synergistically to provide food with lower antinutritional levels.

The purpose of this review was to synthesize the availability of antinutrients, clear their effect on the human body, and commemorate possible paths to disable them. This review provides links to the available literature as well as enables a systematic view of the recently published research on the topic of plant-based antinutrients.

Effects of feed iodine concentrations and milk processing on iodine concentrations of cows' milk and dairy products, and potential impact on iodine intake in Swiss adults

The contribution of milk and dairy products to daily iodine intake is high but variable in many industrialised countries. Factors that affect iodine concentrations in milk and dairy products are only poorly understood. Our aim was to: (1) assess the effect of feed iodine concentration on milk iodine by supplementing five groups of five cows each with one of five dosages from 0-2 mg iodine/kg DM; (2) quantify iodine losses during manufacturing of cheese and yogurt from milk with varying iodine concentrations and assess the effect of cellar-ripening; and (3) systematically measure iodine partitioning during heat treatment and skimming of milk. Milk iodine reached a near-steady state after 3 weeks of feeding. Median milk iodine (17-302 μg/l for 0-2 mg iodine/kg DM) increased linearly with feed iodine (R2 0·96; P < 0·001). At curd separation, 75-84 % of iodine was lost in whey. Dairy iodine increased linearly with milk iodine (semi-hard cheese: R2 0·95; P < 0·001; fresh cheese and yogurt: R2 1·00; P < 0·001), and cellar-ripening had no effect. Heat treatment had no significant effect, whereas skimming increased (P < 0·001) milk iodine concentration by only 1-2 μg/l. Mean daily intake of dairy products by Swiss adults is estimated at 213 g, which would contribute 13-52 % of the adults' RDA for iodine if cow feed is supplemented with 0·5-2 mg iodine/kg DM. Thus, modulation of feed iodine levels can help achieve desirable iodine concentrations in milk and dairy products, and thereby optimise their contribution to human iodine nutrition to avoid both deficiency and excess.

Effect of Different Processing Methods on the Accumulation of the Phenolic Compounds and Antioxidant Profile of Broomcorn Millet (Panicum miliaceum L.) Flour

Broomcorn millet (Panicum miliaceum L.) is an important nutritious ancient minor-cereal food crop. However, this crop is little explored in the food processing arena to improve its functionality. In this context, different processing methods were applied to enhance the secondary compounds of broomcorn millet. Four different individual methods such as roasting, steaming, puffing, and extrusion were applied at 110 °C to enhance the functional attributes of millet flour. It was observed that the significantly highest content of total phenolic (TP) (670 mg/100 g of ferulic acid equivalent) and total flavonoid (TF) (391 mg/100 g of rutin equivalent ) was attained in the roasted whole millet followed by steaming (315 mg/100 g, 282 mg/100 g), puffing (645 mg/100 g, 304 mg/100 g), extrusion (455 mg/100 g, 219 mg/100 g), and control (295 mg/100 g, 183 mg/100 g). The chromatographic analysis showed a greater content of single phenolic acids such as syringic acid, gallic acid, 4-hydroxy benzoic acid, ferulic acid, sinapic acid, and catechin in roasted millet compared to control, and the content of each acid was higher in whole millet than dehulled. Results also indicated that the content of ferulic acid was relatively higher among the quantified single phenolic acid from broomcorn millet. Likewise, in comparison with dehulled millet, the roasted whole millet showed higher total antioxidant capacity, measured by the 2,2-diphenyl-1 picryl hydrazyl (DPPH), the ferric reducing antioxidant power assay (FRAP), the phosphomolybdenum method (PPMD), and the hydroxyl radical scavenging capacity (HRSC) method. Lastly, it is concluded that the roasting method should be taken into consideration in the processing of broomcorn millet to enhance the content of nutraceutical compounds and improve its functionality.

Iodine status five years after the mandatory salt iodization legislation indicates above requirement: a cross sectional study in Northwest Ethiopia

Background

Iodine deficiency is one of a major nutritional problem. The study aimed to assess the iodine status of populations in Dabat district using median urinary iodine concentration (UIC) in school-age children (6–12 years) and compared the results with goiter prevalence.

Methods

The study used a cross-sectional study design. The study was conducted in Dabat district, northwest Ethiopia in May 2016. Spot urine samples were used for the determination of UIC. Manual examination of the thyroid gland was performed to assess presence of goiter. The MBI international Rapid Test Kits (RTK) were used to determine the level of salt iodine content. Children aged 6–12 years were recruited from schools using a multistage stratified sampling. One-way Analysis of Variance (ANOVA) was used to compare mean of log-transformed UIC values among key variables. Significant was determined at P-value less than 0.05.

Results

A total of 358 school age children enrolled to the study. The mean age of children was 10.8((Standard Deviation (SD) = 1.45) years and 56.7% were males. The median UIC was 235 μg/l ((Inter Quartile Range (IQR): 161, 320]. Excessive iodine intake and inadequate iodine intake was observed on 29.1 and 8.7% of school aged children, respectfully. The coverage of iodized salt use in school-age children were 66.8%. The UIC was higher in urban children than rural counterparts and in those used adequately iodised salt than inadequately iodized salt (P < 0.05). Thirty-four percent of school-age children had a goiter. The prevalence of grade 1 and grade 2 goiter was 26.5 and 7.5%, respectively. There was a poor agreement between UIC and goiter (k = 0.1) in classifying iodine status of populations.

Conclusions

The study population is classified as above requirements by median UIC in school-age children but severe iodine deficiency by goiter prevalence. Further research investigating the agreement between UIC and goiter prevalence in classifying iodine status of populations with various iodine status is warranted.

Human T2R38 Bitter Taste Receptor Expression in Resting and Activated Lymphocytes

The human G-protein-coupled bitter taste receptor T2R38 has recently been demonstrated to be expressed on peripheral blood neutrophils, monocytes and lymphocytes. To further define a potential contribution of the T2R38 receptor in adaptive immune response, the objective of this study was to analyze its expression in resting and activated lymphocytes and T cell subpopulations. Freshly isolated PBMC from healthy donors were used for expression analysis by flow cytometry. Quantum™ MESF beads were applied for quantification in absolute fluorescence units. Activation methods of T cells were anti-CD3/CD28, phytohaemagglutinin (PHA) or phorbol 12-myristate 13-acetate (PMA) together with ionomycin. Lymphocytes from young donors expressed higher levels of T2R38 compared to the elderly. CD3+ T cells expressed higher levels that CD19+ B cells. Receptor expression followed T cell activation with an upregulation within 24 h and a peak at 72 h. Higher levels of T2R38 were produced in lymphocytes by stimulation with anti-CD3/CD28 compared to PHA or PMA/ionomycin. Both subpopulations of CD4+ as well as CD8+ T cells were found to express the T2R38 receptor; this was higher in CD4+ than CD8+ cells; the amount of T2R38 in central and effector memory cells was higher as compared to naïve cells, although this was not statistically significant for CD8+ cells without prior activation by anti-CD3/CD28. Upon treatment of PBMC with the natural T2R38 agonist goitrin Calcium flux was activated in the lymphocyte population with functional T2R38 receptor at >20 μM which was completely blocked by phospholipase Cβ-2 inhibitor U73211. Further, goitrin selectively inhibited TNF-alpha secretion in PBMC with functional T2R38. This quantitative analysis of T2R38 expression in distinct PBMC subsets may provide a basis for understanding the significance of bitter compounds in immune modulation. Whether these findings can have implications for the treatment of inflammatory and immunologic disorders by bitter tasting pharmaceuticals or foods needs further investigation.

Thyroid Function Disruptors: from nature to chemicals

The modern concept of thyroid disruptors includes man-made chemicals and bioactive compounds from food that interfere with any aspect of the hypothalamus-pituitary-thyroid axis, thyroid hormone biosynthesis and secretion, blood and transmembrane transport, metabolism and local action of thyroid hormones. This review highlights relevant disruptors that effect populations through their diet: directly from food itself (fish oil and polyunsaturated fatty acids, pepper, coffee, cinnamon and resveratrol/grapes), through vegetable cultivation (pesticides) and from containers for food storage and cooking (bisphenol A, phthalates and polybrominated diphenyl ethers). Due to the vital role of thyroid hormones during every stage of life, we review effects from the gestational period through to adulthood, including evidence from in vitro studies, rodent models, human trials and epidemiological studies.

Antinutritional factors in pearl millet grains: Phytate and goitrogens content variability and molecular characterization of genes involved in their pathways

Pearl millet [Pennisetum glaucum (L.) R. Br.] is an important "orphan" cereal and the most widely grown of all the millet species worldwide. It is also the sixth most important cereal in the world after wheat, rice, maize, barley, and sorghum, being largely grown and used in West Africa as well as in India and Pakistan. The present study was carried out in the frame of a program designed to increase benefits and reduce potential health problems deriving from the consumption of pearl millet. The specific goal was to provide a database of information on the variability existing in pearl millet germplasm as to the amounts of phytate, the most relevant antinutrient compound, and the goitrogenic compounds C-glycosylflavones (C-GFs) accumulated in the grain.Results we obtained clearly show that, as indicated by the range in values, a substantial variability subsists across the investigated pearl millet inbred lines as regards the grain level of phytic acid phosphate, while the amount of C-GFs shows a very high variation. Suitable potential parents to be used in breeding programs can be therefore chosen from the surveyed material in order to create new germplasm with increased nutritional quality and food safety. Moreover, we report novel molecular data showing which genes are more relevant for phytic acid biosynthesis in the seeds as well as a preliminary analysis of a pearl millet orthologous gene for C-GFs biosynthesis. These results open the way to dissect the genetic determinants controlling key seed nutritional phenotypes and to the characterization of their impact on grain nutritional value in pearl millet.

Development of Databases on Iodine in Foods and Dietary Supplements

Iodine is an essential micronutrient required for normal growth and neurodevelopment; thus, an adequate intake of iodine is particularly important for pregnant and lactating women, and throughout childhood. Low levels of iodine in the soil and groundwater are common in many parts of the world, often leading to diets that are low in iodine. Widespread salt iodization has eradicated severe iodine deficiency, but mild-to-moderate deficiency is still prevalent even in many developed countries. To understand patterns of iodine intake and to develop strategies for improving intake, it is important to characterize all sources of dietary iodine, and national databases on the iodine content of major dietary contributors (including foods, beverages, water, salts, and supplements) provide a key information resource. This paper discusses the importance of well-constructed databases on the iodine content of foods, beverages, and dietary supplements; the availability of iodine databases worldwide; and factors related to variability in iodine content that should be considered when developing such databases. We also describe current efforts in iodine database development in the United States, the use of iodine composition data to develop food fortification policies in New Zealand, and how iodine content databases might be used when considering the iodine intake and status of individuals and populations.

Endemic goiter and iodine deficiency status among Guinea-Bissau school-age children

BACKGROUND/OBJECTIVES

Iodine deficiency disorders are estimated to affect 25% of all school-age children around the world. Current policies concerning iodine deficiency disorders in many countries are not based on robust or recent national data. Our objective was to evaluate the current status of iodine nutrition in Guinea-Bissau (West Africa).

SUBJECT/METHODS

A cross-sectional survey including 299 school-age children, aged 6-14 years old, from four distinct regions of Guinea-Bissau across a coast-hinterland gradient (Bolama, Bissau, Cambaju-Bafatá, and Gabú) was performed. Several iodine deficiency disorders indicators were used: total goiter rate, median urinary iodine concentration (UIC) and regional iodine content in household salt and drinking water samples. Data on the total goiter rate were obtained by thyroid ultrasound.

RESULTS

Goiter was found in 73.5% (CI 95%, 68.5-78.2%) of the school-age children. We observed a median urinary iodine concentration of 110  mcg/l, with 7.3% of the studied population presenting urinary iodine concentration  < 50  mcg/l. Only 12.5% of the household salt samples revealed iodine content ≥  15  mg/kg. Median well water iodine concentration was 11.7  mcg/l.

CONCLUSIONS

Guinea-Bissau presents high rates of goiter in school-age children despite satisfactory median urinary iodine concentration population levels. Salt and drinking water iodine median content cannot explain these findings. Further studies following the progress in iodine deficiency status and the presence of potential goitrogens in diet of this vulnerable population are in needed.

Iodine in dairy milk: Sources, concentrations and importance to human health

Milk and dairy products are major iodine sources in industrialized countries. However, consumption of milk and dairy, as well as their iodine concentrations, vary widely, making them an unpredictable iodine source. Milk iodine concentrations in industrialized countries range from 33 to 534 μg/L and are influenced by the iodine intake of dairy cows, goitrogen intake, milk yield, season, teat dipping with iodine-containing disinfectants, type of farming and processing. We estimate milk and dairy contribute ≈13-64% of the recommended daily iodine intake based on country-specific food intake data. To ensure adequate iodine levels but avoid the risk of iodine excess through milk and dairy, it is crucial to reduce the wide variations in milk iodine. If iodine intakes from iodized salt fall because of public health efforts to reduce salt intake, milk and dairy products may become increasingly important sources of dietary iodine in the future.

Effect of Nitrates, Thiocyanates and Selenium on the Iron and Iodine Status of Postpartum Women

AIM

To find correlations between high thiocyanate and nitrate levels and low selenium levels and the indicators of the iodine and iron status of postpartum women.

MATERIALS AND METHODS

The study included 41 mothers aged 26.4±5.9 yrs from Asenovgrad and nearby villages. Urinary iodine was determined by the Sandell-Kolthoff reaction and thiocyanate - by the interaction of these ions with acidic solution of KMnO4; for serum nitrates we used the colorimetric method; serum selenium was assessed by electro-thermal atomic-absorption spectrophotometry; thyroxin (FT4), the thyroid stimulating hormone (TSH), serum ferritin (SF), and serum transferrin receptor (sTfR) were determined using ELISA; Hb levels were determined by hematology analyzer.

RESULTS

Assessing the iodine status, we found a negative correlation between the levels of iodine and thiocyanates in urine (R=-0.717, р<0.0001), a positive correlation between nitrates and TSH (R=0.487, р=0.003) and a negative correlation between nitrates and FT4 (R=-0.312, р=0.06). For the iron status, we found a negative correlation between nitrates and SF (R=-0.429, р=0.009) and between nitrates and Hb (R=-0.383, р=0.021). The Mann-Whitney U-test showed that in women with nitrate levels higher than the mean value there was low FT4 level (р=0.06), high TSH level (р=0.013), low Hb concentration (р=0.061) and low SF concentration (р=0.005). The combined effects of environmental factors (elevated nitrate levels and low selenium level) on the iodine and iron status are manifested by low concentrations of FT4 (р=0.033), Hb (р=0.06) and SF (р=0.05) and high level of TSH (р=0.05). In conclusion, we found that environmental factors, especially when combined, have a negative impact on the iron and iodine status of females.

Cultivar-Specific Changes in Primary and Secondary Metabolites in Pak Choi (Brassica Rapa, Chinensis Group) by Methyl Jasmonate

Glucosinolates, their hydrolysis products and primary metabolites were analyzed in five pak choi cultivars to determine the effect of methyl jasmonate (MeJA) on metabolite flux from primary metabolites to glucosinolates and their hydrolysis products. Among detected glucosinolates (total 14 glucosinolates; 9 aliphatic, 4 indole and 1 aromatic glucosinolates), indole glucosinolate concentrations (153-229%) and their hydrolysis products increased with MeJA treatment. Changes in the total isothiocyanates by MeJA were associated with epithiospecifier protein activity estimated as nitrile formation. Goitrin, a goitrogenic compound, significantly decreased by MeJA treatment in all cultivars. Changes in glucosinolates, especially aliphatic, significantly differed among cultivars. Primary metabolites including amino acids, organic acids and sugars also changed with MeJA treatment in a cultivar-specific manner. A decreased sugar level suggests that they might be a carbon source for secondary metabolite biosynthesis in MeJA-treated pak choi. The result of the present study suggests that MeJA can be an effective agent to elevate indole glucosinolates and their hydrolysis products and to reduce a goitrogenic compound in pak choi. The total glucosinolate concentration was the highest in "Chinese cabbage" in the control group (32.5 µmol/g DW), but indole glucosinolates increased the greatest in "Asian" when treated with MeJA.

Effects of Different Processing Methods on the Antioxidant Activity of 6 Cultivars of Foxtail Millet

The total phenolic content (TPC) of millet was whole > dehulled > cooked > steamed and the bound phenolic content (BPC) was the main form. Compared with dehulled millet, the TPC, TFC, and phenolic acid contents were decreased significantly (P< 0.05). The retention rate of TPC of steamed millet ranged from 47% to 55% and cooked millet ranged from 55% to 79%. Additionally, the mean cinnamic acid content of cooked millet was 1.29 times as much as steamed millet. The antioxidant activity of millet was whole > dehulled > cooked > steamed. Therefore, cooked millet was a good choice for human.

Role of medical resource level in iodine deficiency disorder

BACKGROUND

Iodine deficiency disorders (IDDs) refer to a series of diseases caused by the human body's insufficient iodine intake. Edible salt became iodized in China in 1996, which yielded remarkable results. We have known that IDDs is associated with iodine in the human body, but it is not clear whether IDDs is related to medical resource level.

METHODS

We collected the number of IDDs cases and an index for the level of medical resource from 31 provinces, autonomous regions and municipalities directly under the central government in China. All data came from the China Statistical Yearbook of Health and Family Planning issued in 2013 by the Peking Union Medical College Publishing House. Data standardization and linear regression analysis were used.

RESULTS

The results showed that IDDs correlated with the number of beds in medical and health institutions, number of medical health personnel, number of medical and health institutions, total health expenditure, average health expenditure per capita, medical insurance for urban resident and new rural cooperative medical rural residents (P < 0.01). In a multiple linear regression, IDDs was most significantly associated with the number of beds in hospitals, the number of rural health personnel, the number of basic medical and health institutions and government health expenditure for these institutions.

CONCLUSION

Based on the experimental data, we concluded that IDDs had a positive connection with the medical resource level, and basic and rural areas had a more significant association with IDDs. This analysis provides new and explicit ideas for iodine prevention and control work in China.

Iodine deficiency and associated factors among school children: a cross-sectional study in Ethiopia

Background

Iodine deficiency remains a public health problem in the world. It is the leading cause of preventable mental retardation and brain damage worldwide. Though 12 million school age children are at risk of developing iodine deficiency, there is a scarcity of literature showing the magnitude of iodine deficiency in Ethiopia. Therefore, this study aimed to determine the prevalence and associated factors of iodine deficiency among school children in Robe District, southeast Ethiopia.

Methods

A school based cross–sectional study was conducted from February to June, 2015. A structured interviewer-administered questionnaire was used to collect data. A systematic random sampling technique was employed to select 422 children. A multivariate logistic regression analysis was carried out to identify factors associated with iodine deficiency. In the multivariate analysis, variables with a P-value of <0.05 were considered statistically significant.

Results

A total of 393 school children participated in the study. The median urinary iodine level was 78 μg/l. About 57 and 43.5 % of the children were found with low urinary iodine level and goiter, respectively. Only 29 % of the households utilized adequately iodized salt. The result of the multivariate analysis revealed that the odds of iodine deficiency were higher among female [AOR = 2.23; 95 % CI: 1.54, 3.55] and older (10–12 years) [AOR = 2.21; 95 % CI: 1.44, 3.42] children.

Conclusion

In this community, the prevalence of goiter and low urine iodine level is high. Thus, iodine deficiency exists as severe public health problem. In addition, there is a low utilization of iodized salt in the setting. Therefore, it is crucial to intensify efforts in the implementation of iodized salt. Moreover, attention should be given to school children to address ID.

Iodine source apportionment in the Malawian diet

The aim of this study was to characterise nutritional-I status in Malawi. Dietary-I intakes were assessed using new datasets of crop, fish, salt and water-I concentrations, while I status was assessed for 60 women living on each of calcareous and non-calcareous soils as defined by urinary iodine concentration (UIC). Iodine concentration in staple foods was low, with median concentrations of 0.01 mg kg⁻¹ in maize grain, 0.008 mg kg⁻¹ in roots and tubers, but 0.155 mg kg⁻¹ in leafy vegetables. Freshwater fish is a good source of dietary-I with a median concentration of 0.51 mg kg⁻¹. Mean Malawian dietary-Iodine intake from food, excluding salt, was just 7.8 μg d⁻¹ compared to an adult requirement of 150 μg d⁻¹. Despite low dietary-I intake from food, median UICs were 203 μg L⁻¹ with only 12% defined as I deficient whilst 21% exhibited excessive I intake. Iodised salt is likely to be the main source of dietary I intake in Malawi; thus, I nutrition mainly depends on the usage and concentration of I in iodised salt. Drinking water could be a significant source of I in some areas, providing up to 108 μg d⁻¹ based on consumption of 2 L d⁻¹.

An outbreak of thyroid hyperplasia (goiter) with high mortality in budgerigars (Melopsittacus undulatus)

An outbreak of goiter with high morbidity and mortality in a flock of budgerigars (Melopsittacus undulatus) in California is described. Forty-five out of 400 adult birds exhibited signs of illness, weight loss, and enlargement in the crop area; 15 of the 45 birds died over a 2-3-month period. Diet consisted of a commercial mixture with the addition of broccoli, whole oats, and carrots, but no minerals or supplements. Six budgerigars were subjected to necropsy; all 6 birds had severely enlarged thyroid glands. Thyroid follicular hyperplasia was histologically observed in all birds examined, while granulomatous thyroiditis and microfollicular adenoma were observed in 2 birds, respectively. Virological, bacteriological, parasitological, and heavy metal analyses were negative or within normal limits. The total iodine in the thyroid glands of affected birds was measured by inductively coupled plasma-mass spectrometry. Following iodine supplementation and removal of broccoli from the diet, the owner reported weight gain and a reduced death rate among clinically affected birds; no additional birds became sick. The presence of broccoli with its iodine-binding ability and the complete lack of added minerals in the diet of these animals were thought to be the predisposing factors for the outbreak in the present study. Outbreaks of goiter accompanied by high mortality are rare in any species and, to the best of the authors' knowledge, have not been described previously in any avian species. Recognition of this condition may help improve medical, welfare, and trade standards concerning this species.

Reactivity and stability of glucosinolates and their breakdown products in foods

The chemistry of glucosinolates and their behavior during food processing is very complex. Their instability leads to the formation of a bunch of breakdown and reaction products that are very often reactive themselves. Although excessive consumption of cabbage varieties has been thought for long time to have adverse, especially goitrogenic effects, nowadays, epidemiologic studies provide data that there might be beneficial health effects as well. Especially Brassica vegetables, such as broccoli, radish, or cabbage, are rich in these interesting plant metabolites. However, information on the bioactivity of glucosinolates is only valuable when one knows which compounds are formed during processing and subsequent consumption. This review provides a comprehensive, in-depth overview on the chemical reactivity of different glucosinolates and breakdown products thereof during food preparation.

Genetic and non-iodine-related factors in the aetiology of nodular goitre

Genetic and a large number of environmental non-iodine-related factors play a role in the cause of nodular goitre. Most evidence for the influence of genetic and environmental factors in the cause of goitre is from cross-sectional, population-based studies. Only a few studies have included prospective data on risk factors for nodular goitre, although few prospective data are available on the effect of iodine and tobacco smoking on goitre development. Goitre is not one single phenotype. Many epidemiological studies do not distinguish diffuse from nodular goitre, as the investigated parameter is often thyroid volume or frequency with increased thyroid volume. Moreover, information on the presence and effect of gene-environment, gene-gene, and environment-environment effect modifications is limited. Thus, firm conclusions about the relative contributions and causality of the investigated risk factors should be made with caution. Smoking seems to be an established risk factor for nodular goitre, possibly with effect modification from iodine intake, as the risk associated with smoking is smaller or absent in areas with sufficient iodine intake. The use of oral contraceptives might have protective effects against goitre, and childbirth is an increased risk factor for goitre in areas with non-optimal iodine intake. Insulin resistance is a recently investigated risk factor, and the risk of goitre may be reversible with metformin treatment. Iodine remains the major environmental risk factor for nodular goitre.

Prevalence and associated factors of goiter among rural children aged 6-12 years old in Northwest Ethiopia, cross-sectional study

Background

Goiter, an indicator of chronic iodine deficiency, is a major public health problem for populations living with iodine deficient environment, particularly for young children. It is a threat to the social and economic development of many developing countries including Ethiopia. The aim of the study was to assess the prevalence and associated factors of goiter among rural children aged 6-12 years, Northwest Ethiopia.

Methods

A community based cross-sectional study was employed from July to December 2012 in Lay Armachiho district. A total of 698 children aged 6-12 years were included in the study. Multistage sampling was used. Children were examined for the presence/absence of goiter using a criterion set by World Health Organization. The level of Iodine of the salt was estimated by using spot testing kits. Descriptive and summary statistics were employed. Bivariate and multivariate logistic regressions were used to identify associated factors. The degree of association was assessed by using Odds ratio with 95% confidence interval were computed to see the presence and strength of association.

Results

Totally 694 children were included in the analysis. The prevalence of goiter was found to be 37.6%. Goiter of grade 1 was 28.5% and that of grade 2 was 9.1%. 29.7% of the samples had adequate iodine content. The age of child (AOR: 1.24,95% CI: 1.12, 1.36), being female (AOR = 1.98, 95% CI: 1.38-2.85), salt iodine level (AOR = 0.44, 95% CI: 0.27, 0.71), family history of goiter (AOR = 3.18, 95% CI: 2.08, 4.858), fish consumption (AOR = 0.42, 95% CI; 0.22, 0.80) were factors associated with goiter.

Conclusion

Chronic iodine deficiency was a severe public health problem in the study communities. Ensuring the consumption of iodized salt and promotion of fish intake at the household level are highly recommended.

Role of bamboo-shoot in the pathogenesis of endemic goiter in manipur, north East India

OBJECTIVE

Endemic goiter is prevalent in the iodine-sufficient region of Manipur, India. Bamboo shoot (BS), a goitrogenic plant food, are consumed regularly in the area. The objective of this study was to examine the role of BS in the pathogenesis of endemic goiter.

METHODS

Goiter prevalence, urinary iodine, and thiocyanate (SCN) excretion in school children, iodine content in drinking water, and the household consumption of salt fortified with iodine were measured. To confirm the goitrogenic potential of BS, its progoitrogenic constituents were fed to rats as part of an iodine-sufficient diet, after which the animals' thyroid gland morphology and functional status were assessed.

RESULTS

Goiter prevalence was 31% in 4852 children, and the median urinary I and SCN levels were 176.3 μg/L and 0.962 ± 0.190 mg/dL, respectively. Of the households assessed, 90% consumed salt fortified with adequate iodine. Progoitrogenic constituents were high in BS from Manipur. Increased thyroid weight, hypertrophy and hyperplasia of follicular cells, decreased thyroid peroxidase activity, and low serum thyroxine (T4) and triiodothyronine (T3) levels were observed in BS-fed rats.

CONCLUSION

Nearly one third of the studied participants had palpable goiter, despite a successful salt iodine fortification program. SCN from BS causes goiter in iodine-sufficient experimental animals. Similar ingestion in study participants was confirmed and is the likely cause for the persistence of endemic goiter in the Manipur region.

Goiter frequency is more strongly associated with gastric adenocarcinoma than urine iodine level

PURPOSE

We designed our study to evaluate the hypothesis that gastric cancer is correlated with iodine deficiency or thyroid dysfunction.

MATERIALS AND METHODS

We investigated the total body iodine reserve, thyroid function status and autoimmune disorder in 40 recently diagnosed gastric adenocarcinoma cases versus 80 healthy controls. The participants came from a region with high gastric cancer rate but sufficient iodine supply due to salt iodination. The investigation included urine iodine level, thyroid gland clinical and ultrasonographic examination, and thyroid function tests.

RESULTS

Goiter was detected more frequently in the case group (P=0.001); such a finding, however, was not true for lower than normal urine iodine levels. The free T3 mean level was significantly lower in the case group compared to the control group (P=0.005).

CONCLUSIONS

The higher prevalence of goiter rather than low levels of urinary iodine in gastric adenocarcinoma cases suggests that goiter, perhaps due to protracted but currently adjusted iodine deficiency, is more likely to be associated with gastric adenocarcinoma compared to the existing iodine deficiency itself.

Iodine concentration in commercial cat foods from three regions of the USA, 2008–2009

Fluctuations in iodine concentration in food have been suggested as one risk factor for the development of feline hyperthyroidism, an epidemic disease first described in 1979. Three international studies have examined iodine concentrations of commercial cat foods. The iodine concentration of 112 commercial cat foods from across the USA was measured, and the daily iodine intake by hypothetical 4.5 kg adult cats or 1.4 kg kittens calculated in this descriptive epidemiologic study to examine differences in feline iodine intake due to (i) geographical source of foods, (ii) packaging type, (iii) brand-to-brand variation, (iv) form of iodine supplementation, (v) types and numbers of seafood ingredients and (vi) kitten and ‘therapeutic’ diets. Dramatic variation among canned foods (resulting in ingestion of approximately 49–9639 μg iodine/day) suggests that the disparity in iodine concentrations may lead to development of nodular hyperplasia and, later, clinical hyperthyroidism, if cats consume diets that are at first iodine-deficient and later contain excessive iodine. Manufacturers are encouraged to ensure adequate iodine supplementation across all products and areas of the USA.

Hyperthyroidism in Cats

Practical relevance:

Since first being reported in the late 1970s, there has been a dramatic increase in the prevalence of hyperthyroidism in cats. It is now recognized worldwide as the most common feline endocrine disorder.

Patient group:

Hyperthyroidism is an important cause of morbidity in cats older than 10 years of age. It is estimated that over 10% of all senior cats will develop the disorder.

Clinical challenges:

Despite its frequency, the underlying cause(s) of this common disease is/are not known, and no one has suggested a means to prevent the disorder. Because of the multiple risk factors that have been described for feline hyperthyroidism, it is likely that more than one factor is involved in its pathogenesis. Continuous, lifelong exposure to environmental thyroid disruptor chemicals or goitrogens in food or water, acting together in an additive or synergistic manner, may first lead to euthyroid goiter and then to autonomous adenomatous hyperplasia, thyroid adenoma and hyperthyroidism.

Evidence base:

This review draws on published research studies to summarize the available evidence about the risk factors for feline hyperthyroidism. Based on the known goitrogens that may be present in the cat’s food, drinking water or environment, it proposes measures that cat owners can implement that might prevent, or reduce the prevalence of, thyroid tumors and hyperthyroidism in their cats.

Dietary calcium induced cytological and biochemical changes in thyroid

Certain epidemiological studies revealed correlation between hard water consumption (with high calcium) and thyroid size of the population, though the possible alterations in thyroid physiology upon calcium exposure are still inconclusive. Adult male Wistar strain rats were subjected to calcium treatment at the doses of 0.5g%, 1.0g% and 1.5g% calcium chloride (CaCl(2)) for 60 days. The parameters studied were - thyroid gland weight, histopathology, histomorphometry; thyroid peroxidase (TPO), 5'-deiodinase I (DI), sodium-potassium adenosine triphosphatase (Na(+)-K(+)-ATPase) activities; serum total and free thyroxine (tT4, fT4), total and free triiodothyronine (tT3, fT3), thyroid stimulating hormone (TSH) levels. Enlargement of thyroid with hypertrophic and hyperplastic changes, retarded TPO and 5'-DI but enhanced Na(+)-K(+)-ATPase activities, augmented serum total and free T4 and TSH but decreased total and free T3 levels and low T3/T4 ratio (T3:T4) were observed in the treated groups. All these findings indicate development of goitrogenesis upon exposure to excessive dietary calcium.

Feline Hyperthyroidism: Potential Relationship with Iodine Supplement Requirements of Commercial Cat Foods

Article rationale Since the late 1970s, there has been a significant increase in the prevalence of feline hyperthyroidism (FH). It is now recognized worldwide as the most common endocrinopathy of older cats, resembling toxic nodular goiter of older humans in iodine-deficient areas. The purpose of this article is to identify the potential for iodine concentrations in the diet to contribute to the etiology of FH.

Historical context Iodine concentrations of commercial cat foods vary widely. A review of historical iodine recommendations revealed that the units of iodine supplementation changed in the 1970s. Given this change, foods minimally supplemented since the late 1970s would have been iodine deficient for most cats.

Practical relevance Iodine supplementation of commercial cat foods should be evaluated in the light of the iodine recommendations revised in 2006. Foods may remain deficient in iodine if supplemented at the minimum recommended concentration, possibly contributing to the development of FH.