Salt iodisation of processed foods in Germany: evidence, processors' perceptions and implications for public health

PurposeThe authors provide primary data on salt iodisation of processed foods in Germany, analyse reasons for food processors' use or non-use of iodisation and derive implications for public health.Design/methodology/approachStatistical evidence is presented on the use of iodised salt in bread and bakery products, meat and meat products and dairy products in the German grocery-retailing sector. Information is based on mobile data collection in a representative sample of grocery stores in four German cities. These data are analysed with logistic regression models. Additionally, an online survey of bakers and butchers is utilised to record and to explain the use of iodised salt in specialised food stores.FindingsSalt was added in 69.3% of the 29,910 foods analysed in the market study. When salt was added, iodised salt was used in only 28.5% of the cases. According to the online survey, only 44% of the bakers and butchers used iodised salt, and the user share declined over time. Incomplete information from processors on the role of iodised salt for public health is contributing to the low and declining user share.Originality/valueThe authors combine different market research methods and elaborate that the recommendation by the German Federal Ministry of Food and Agriculture – “If salt, then iodised salt” – is implemented to a very limited extent by the food industry and specialised food stores. From the behaviour of food processors and their perceptions of salt iodisation, the authors gain new insights for policy and public health.

Assessment of the Impact of Salt Iodisation Programmes on Urinary Iodine Concentrations and Goitre Rates: A Systematic Review

Introduction. Two main strategies are currently recommended for the prevention and control of iodine deficiency in the world: implementation of universal salt iodisation programmes and permanent monitoring of iodine consumption by the population. Although iodine intake and coverage iodised salt have increased in the world population, iodine deficiency disorders (IDDs) may still be a public health problem in a few countries or communities. Objective. To assess the impact of salt iodisation programmes on urinary iodine concentrations and goitre rates in the world population. Methodology. A systematic review based on the PRISMA method. We obtained articles from Scopus, Science Direct, MEDLINE databases, and other sources between March and April 2020, without limitation of dates. “Iodisation” AND “urinary iodine concentrations” AND “goitre” in English, Portuguese, and Spanish without filters and clinical trial, case-control, and cross-sectional studies were included in this review. Results. Of 479 abstracts, twenty-three were eligible. Coverage on iodised salt was in the range of 16 to 98%, and 11 studies had been sufficient, whilst eight studies had adequate iodine concentration in salt and three excess. 81.8% of studies that had an adequate median of UIC had a good impact in their respective salt iodisation programmes. Conclusion. After 18 years of salt iodisation programme implementation in the 13 countries, the majority achieved sustaining elimination of IDD whilst all had adequate median UIC; however, more detailed studies are still needed to confirm that all communities are equally protected of IDD.

Nutritional Iodine Status in Pregnant Women from Health Area IV in Asturias (Spain): Iodised Salt Is Enough

Background: Iodine deficiency during pregnancy may have adverse effects on the neurodevelopment of the foetus. Recent studies of pregnant women in Asturias (Spain) indicate that nutritional iodine levels are sufficient. The objective of this study was to confirm the appropriate nutritional iodine status and to analyse the influence of the ingestion of iodine on maternal urinary iodine concentration (UIC) and thyroid function. Methods: An observational study was carried out between May and June 2017 on women in the first trimester of pregnancy from Health Area IV in Asturias. The women completed a questionnaire related to their consumption of iodine and samples were taken to analyse UIC and thyroid function. Results: Three hundred and eighteen pregnant women were involved. Of these, 51.10% used iodised salt, 48.90% consumed ≥ 2 servings of dairy products daily and 87.08% took iodine supplements. The median UIC was 171.5 μg/L (116–265 μg/L) and 60.41% of women had UIC ≥ 150 μg/L. Multivariate logistic regression analysis demonstrated that iodised salt had a protective effect on UIC < 150 μg/L (odds ratio (OR) 0.404 (0.237–0.683), p = 0.001), but not iodine supplements (OR 0.512 (0.240–1.085), p = 0.080). The average level of thyroid stimulating hormone (TSH) was 2.26 ± 0.94 mIU/L; 68.40% of pregnant women taking iodine supplements had TSH < 2.5 mIU/L compared to 30.00% of those who were not taking supplements (p = 0.031). Conclusions: The pregnant women in our health area are maintaining appropriate nutritional iodine levels. The consumption of iodised salt protects against iodine deficiency; thus, iodine supplements should be taken on an individualised basis.

Iodine status in women attending Mnazi Mmoja Hospital in Zanzibar: a matched case-control study

BackgroundIodine deficiency can have adverse health effects in all age groups affecting growth, development and cognitive functions as well as the incidence of goitre. Worldwide, the most important dietary source of iodine is iodised salt. In Tanzania, iodine intake has varied due to multiple salt suppliers producing iodised salt with varying quality. Zanzibar has faced challenges with the packing, storing and monitoring of salt iodisation, and universal salt iodisation has not been achieved. Furthermore, the number of available studies on the iodine status in Zanzibar are sparse.ObjectiveThe main objective of this study is to describe the iodine status of euthyroid female adult patients with and without goitre in Zanzibar.Design and methodsA single-centre matched case-control study was conducted among 48 female patients at the ear, nose and throat clinic of Mnazi Mmoja Hospital, Zanzibar. Blood samples were drawn for serum-analysis of the thyroid hormone profile to confirm that all patients were euthyroid prior to inclusion. Urinary iodine concentrations and the iodine concentration in household salt samples were analysed. A semiquantitative food frequency questionnaire (FFQ) was used to describe trends in the dietary intake of iodine-rich and goitrogenic foods. Clinical examinations were conducted, and the patients were categorised into goitre (cases) and non-goitre (controls) groups.ResultsA moderate iodine deficiency (median urinary iodine concentration between 20 and 49 µg/L) was found in patients both with and without goitre. In total, only 35 % of the salt samples were adequately iodised. The salt samples from the cases had a lower average concentration of iodine compared with the controls. The FFQ revealed that the daily consumption of marine fish and the weekly consumption of raw cassava were more frequent in the cases than the controls.ConclusionThese findings suggest that iodine deficiency may be a problem in both patients with and without goitre in Zanzibar. The salt iodisation programme may require monitoring and implementation of satisfactory quality control practices as universal salt iodisation is yet to be achieved in Zanzibar.

Environmental and human iodine and selenium status: lessons from Gilgit-Baltistan, North-East Pakistan

Iodine and selenium deficiencies are common worldwide. We assessed the iodine and selenium status of Gilgit-Baltistan, Pakistan. We determined the elemental composition (ICP-MS) of locally grown crops (n = 281), drinking water (n = 82), urine (n = 451) and salt (n = 76), correcting urinary analytes for hydration (creatinine, specific gravity). We estimated dietary iodine, selenium and salt intake. Median iodine and selenium concentrations were 11.5 (IQR 6.01, 23.2) and 8.81 (IQR 4.03, 27.6) µg/kg in crops and 0.24 (IQR 0.12, 0.72) and 0.27 (IQR 0.11, 0.46) µg/L in water, respectively. Median iodised salt iodine was 4.16 (IQR 2.99, 10.8) mg/kg. Population mean salt intake was 13.0 g/day. Population median urinary iodine (uncorrected 78 µg/L, specific gravity-corrected 83 µg/L) was below WHO guidelines; creatinine-corrected median was 114 µg/L but was unreliable. Daily selenium intake (from urinary selenium concentration) was below the EAR in the majority (46–90%) of individuals. Iodine and selenium concentrations in all crops were low, but no health-related environmental standards exist. Iodine concentration in iodised salt was below WHO-recommended minimum. Estimated population average salt intake was above WHO-recommended daily intake. Locally available food and drinking water together provide an estimated 49% and 72% of EAR for iodine (95 µg/day) and selenium (45 µg/day), respectively. Low environmental and dietary iodine and selenium place Gilgit-Baltistan residents at risk of iodine deficiency disorders despite using iodised salt. Specific gravity correction of urine analysis for hydration is more consistent than using creatinine. Health-relevant environmental standards for iodine and selenium are needed.

Iodine knowledge is associated with iodine status in Portuguese pregnant women: results from the IoMum cohort study

Lack of knowledge about iodine has been suggested as a risk factor for iodine deficiency in pregnant women, but no studies have addressed this issue in Portugal. So, the aim of this study was to investigate iodine knowledge among Portuguese pregnant women and its association with iodine status. IoMum, a prospective observational study, included 485 pregnant women recruited at Centro Hospitalar e Universitário de S. João, Porto, between the 10th and 13th gestational weeks. Partial scores for knowledge on iodine importance, on iodine food sources or on iodised salt were obtained through the application of a structured questionnaire. Then, a total iodine knowledge score was calculated and grouped into low, medium and high knowledge categories. Urinary iodine concentration (UIC) was measured in spot urine samples by inductively coupled plasma MS. Of the pregnant women, 54 % correctly recognised iodine as important to neurocognitive development, 32 % were unable to identify any iodine-rich food and 71 % presented lack of knowledge regarding iodised salt. Of the women, 61 % had a medium total score of iodine knowledge. Knowledge on iodine importance during pregnancy was positively associated with iodine supplementation and also with UIC. Nevertheless, median UIC in women who correctly recognised the importance of iodine was below the cut-off for adequacy in pregnancy (150 µg/l). In conclusion, knowledge on iodine importance is positively associated with iodine status. Despite this, recognising iodine importance during pregnancy may not be sufficient to ensure iodine adequacy. Literacy-promoting actions are urgently needed to improve iodine status in pregnancy.

Modelling the contribution of iodised salt in industrially processed foods to iodine intake in Macedonia

Evidence from the 1950s showed that Macedonia was iodine deficient. After the introduction of mandatory universal salt iodisation, the country saw a steady increase in iodine intake and decline in goitre prevalence, earning iodine-deficiency free status in 2003. Iodine status assessments in 2007 and 2016 showed adequate iodine intake among school age children (median urinary iodine concentration of 241 µg/L and 236 µg/L respectively). Macedonia participated in the 2019 piloting of the Iodine Global Network Programme Guidance on the use of iodised salt in industrially processed foods to better understand salt and iodised salt intake from food sources other than household salt.Aggregated data from the 2017 Household Consumption and Expenditure Survey (HCES) was used to determine household salt consumption, to identify widely-consumed, salt-containing industrially processed foods and estimate typical daily intake of these foods. The salt content of these foods was estimated using national standards and the Danish food composition database. The percentage of this salt that was iodised was assessed using customs data for salt imports.Although the study has its limitations, including a relatively small selection of foods, the results indicate potential iodine intake from iodised household salt and iodised salt in the selected foods of above 300% of the Estimated Average Requirement and over 220% of the Recommended Nutrient Intake for adults. This was approximately 50% of the tolerable safe Upper Level for iodine intake. The study confirmed high daily salt intake (11.2 grams from household salt only). Successful salt reduction would be expected to reduce iodine intake, however, modelling with 10% and 30% reduction implied this is unlikely to put any population group at risk of deficiency. It is recommended that design and implementation of salt iodisation and salt reduction policies are harmonized, alongside continued regular iodine status monitoring for different population groups.

A study on the iodised salt use pattern amongst the slum dwellers in Kolkata

Background: Iodine deficiency disorders (IDD) are most important causes of preventable brain damage all over the world. Iodization of salt is used as a weapon to prevent IDD through national iodine deficiency disorders control programme and food safety and standards act, 2006 and regulations, 2011. Climatic condition, knowledge about storage and culinary practices pose a problem in maintaining adequate iodine level in salt at the consumer level.Methods: An observational, cross-sectional, descriptive study was carried out in the slum of Baghbazar under the service area of urban health and training centre, R.G. Kar medical college and hospital, Kolkata from 18 April to 30 April 2018. Households were chosen using simple random sampling and one adult representative from each household was interviewed with pre-designed pre-tested schedule.Results: 100% of the households were found to use iodised salt. 19.2% were aware that they were using iodised form of salt. 96.2% people keep the salt in covered container but only 7.7% of them knew that if kept uncovered iodine vaporises from salt. Moreover 40.4% of the respondents were found to keep salt open close to the oven during cooking with 86.5% of them not believing that this practice can have effect on the quality of the salt.Conclusions: Awareness regarding the effect of iodised salt on health, proper storage and use pattern should be initiated for desired sustainable change in practice and strict enforcement of law for curbing sale of non-iodised salt must be implemented so that IDD cease to be a serious public health problem.

Awareness on usage of iodized salt and its treatment effect among dental students

Iodised salt is table salt mixed with minute amounts of the element iodine. The ingestion of iodine prevents iodine deficiency. Worldwide, iodine deficiency affects about two billion people and is the leading preventable cause of intellectual and development disabilities. To create awareness among dental students on the iodizied salt and its treatment effect on iodine deficiency. The questionnaire was based on the observational cross-sectional type of study comprising 100 dental students from the Saveetha Dental College. A self-administered questionnaire was given to the students. It was designed to collect data on the use of iodized salt among dental students through an online survey mode containing a set of 10 questions about the use of iodized salt and is a yes or no type. The results were evaluated based on the answers given by the participants. 84% of the dental students use iodised salt, which is more than half but still, the rest of them did not use iodized salt. 26% of dental students have an iodine deficiency. 83% of the students use iodized salt for cooking. 61 % of the students think that iodised salt is healthy. 32%students have answered that sea salt and 7% Himalayan salt is healthy. 65% of the dental students were aware of average salt consumption per day. Majority of the dental students were aware of iodized salt and its treatment effect on iodine deficiency. However, more needs to create on its adverse effects and its role in dietary intake of iodine.