Micronutrient status and intake in the UK - where might we be in 10 years' time?

No food for thought-How important is breakfast to the health, educational attainment and wellbeing of school-aged children and young people?

There have been reports from teachers of pupils in the United Kingdom arriving at school hungry. Poor nutritional intake during childhood can increase the risk of developing both short- and long-term health problems. Breakfast consumption has been associated with several outcomes including better diet quality and healthier weight status. Nevertheless, skipping breakfast is a frequent behaviour in young people, particularly adolescents, and those from lower socio-economic groups, who are less likely to meet dietary recommendations and nutritional targets. The aim of this narrative review is to explore the contribution of breakfast consumption at home or at school and the impact of breakfast skipping on nutrient intakes in school-aged children (aged 4-18 years), and their effect on weight and cardiometabolic health. We will also summarise evidence for a link with cognitive function and educational attainment. A broadly positive effect of breakfast intake on diet quality, weight status and school-related outcomes was found in the literature, although inconsistencies in findings and methodological limitations within the evidence base are notable. Further research is warranted to better understand impact of breakfast intake and school breakfast provision on longer-term learning, educational attainment and health outcomes. This also needs to consider the cost benefit, type of breakfast and any unintended consequences such as encouraging multiple breakfasts. Breakfast consumption could improve the nutritional intakes of the most vulnerable young people and may help to address inequalities in educational outcomes at least in the short term.

Mineral concentrations in milk from cows fed seaweed (Saccharina latissima) under different basal protein supplementation

Sixteen multiparous Holstein cows in four blocks of 4 × 4 Latin square over 4-week experimental periods were used to study the effects of seaweed (Saccharina latissima) supplement (with/without) and protein source (rapeseed meal (RSM)/wheat distiller's grain (WDG)) on milk mineral concentrations. Dietary treatments did not affect milk production and basic composition. Feeding seaweed slightly decreased milk Ca and Cu concentrations; whilst increased (by 3.3-fold) milk iodine (I) concentration, due to a higher dietary I supply. Substitution of WDG with RSM increased feed-to-milk transfer of Ca, Na, and Se and decreased that of Mg, P, Fe, and Mn; but only reduced milk Mn and I concentrations (the latter by 27 % as a potential result of increased glucosinolate intake). Seaweed supplement can improve milk I content when cows' I supply/availability is limited, but care should be taken to avoid excess milk I contents that may pose nutritional risks for young children.

Variation in macrominerals and trace elements in cows' retail milk and implications for consumers nutrition

Based on previous farm-level studies, this study hypothesised that production system (conventional, CON; organic, ORG; channel island, CHA) and season would cause variation in the concentrations of macrominerals and trace elements in retail milk. On average, milk retained its status as an excellent source of Ca, P, I, and Mo across different demographics, and a very good source of K, Mg, and Zn for children. Compared with CON and ORG, CHA milk contained higher concentrations of Ca, Mg, P, Cu, Mn, and Zn; and lower concentrations of K and I. Macrominerals did not show a clear seasonal pattern but trace elements were all at lower concentrations during the typical grazing season. Variation in mineral concentrations can have implications to Ca and P supply in children, and I and Zn supply across different consumer demographics; while the seasonal variation was more pronounced than that associated with production system.

Impact of low iodine diets on ablation success in differentiated thyroid cancer: A mixed-methods systematic review and meta-analysis

BACKGROUND

Debate remains regarding whether to recommend a low iodine diet (LID) before radioactive-iodine treatment and its duration and stringency. This mixed-methods review aimed to determine if iodine status affects treatment success, the most effective diet to reduce iodine status, and how LID impacts wellbeing.

METHODS

Five electronic databases were searched until February 2021. An effectiveness synthesis (quantitative studies) and views synthesis (qualitative, survey, and experience-based evidence) were conducted individually and then integrated. Quality assessment was undertaken.

RESULTS

Fifty-six quantitative and three qualitative studies were identified. There was greater ablation success for those with an iodine status of <50 mcg/L (or mcg/gCr) compared with ≥250 (odds ratio [OR] = 2.63, 95% confidence interval [CI], 1.18-5.86, n = 283, GRADE certainty of evidence very low). One study compared <50 mcg/L (or mcg/gCr) to 100-199 and showed similar rates of ablation success (OR = 1.59, 95% CI, 0.48-6.15, n = 113; moderate risk of bias). People following a stricter LID before ablation had similar rates of success to a less-strict diet (OR = 0.67, 95% CI, 0.26-1.73, n = 256, GRADE certainty of evidence very low). A stricter LID reduced iodine status more than a less strict (SMD = -0.40, 95% CI, -0.56 to -0.24, n = 816), and reduction was seen after 1 and 2 weeks. The main challenges were a negative impact on psychological health, over restriction, confusion, and difficulty for sub-groups.

CONCLUSIONS

Although a LID of 1-2 weeks reduces iodine status, it remains unclear whether iodine status affects treatment success as only a few low-quality studies have examined this. LIDs are challenging for patients. Higher-quality studies are needed to confirm whether a LID is necessary.

Prevalence of vitamin D and calcium deficiencies and their health impacts on women of childbearing age: a protocol for systematic review and meta-analysis

INTRODUCTION

No systematic reviews has synthesised data on the available evidence to determine the prevalence of calcium and vitamin D deficiencies as a public health problem globally. Therefore, this study presents a protocol for conducting a review and meta-analysis to estimate the prevalence of calcium and vitamin D serum deficiencies in women of childbearing age and stratify these data by age group, urban and rural area, world region and pregnant/non-pregnant women whenever possible.

METHODS AND ANALYSIS

The systematic review protocol involves conducting a literature search in the following databases: PubMed, LILACS, Embase, Scopus and Web of Science. The selected articles will be checked thoroughly, including the references to include grey literature. Cross-sectional studies and baseline data from cohort studies or clinical and community trials conducted with women of childbearing age with representative probabilistic sampling will be included. Two independent researchers will be responsible for article selection and data extraction, and discrepancies, if any, will be dealt with by a third reviewer. Methodological quality and risk of bias will be analysed using the Grading of Recommendations, Assessment, Development and Evaluations and Joanna Briggs Institute's checklist, respectively. The heterogeneity of the estimates between studies will also be evaluated. Dissemination of the key findings from the systematic review will help identify priorities for action, establish dietary guidelines, develop health-related public policies and reduce and combat micronutrient deficiencies among women of childbearing age and their children.

ETHICS AND DISSEMINATION

Formal ethical approval is not required, and findings will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42020207850.

A comparative assessment of the nutritional composition of dairy and plant-based dairy alternatives available for sale in the UK and the implications for consumers' dietary intakes

The popularity of plant-based dairy alternatives (PBDAs) products has grown exponentially in recent years creating a new market of PBDA. The aim of this study was to compare the nutritional content of plant-based alternatives of milk, yogurt and cheese with dairy equivalents and the impact on nutritional intake across the lifespan when they are substituted into UK diets. Nutritional information from cow's milk, yogurt, cheese and PBDAs available on the UK market was collected via manufacturers information. The products were categorised according to primary plant-based ingredient/s and compared with the equivalent dairy product. The National Diet and Nutrition Survey data was used to calculate the intake of milk, yogurt and cheese across all age groups and the energy and nutrient intake was calculated. Plant-based milk, cheese and yogurt alternative categories were then substituted for dairy intakes, and energy and nutrient intakes were calculated and compared to UK Dietary Reference Values. A total of 299 PBDA products were identified consisting of 136 milk alternatives, 55 yogurt alternatives and 109 cheese alternatives. All PBDAs were more expensive than dairy products. Milk contained more energy, saturated fat, carbohydrates, protein, vitamin B₂, vitamin B₁₂ and iodine, and less fibre and free sugars, than plant-based milk alternatives (P < 0.05). There were significant differences between yogurt and cheese and their corresponding PBDAs for energy, fat, saturated fat, carbohydrate, sugars, fibre protein, salt, and calcium (P < 0.05). These differences were reflected in the nutrient intakes of different age groups and the results demonstrated that PBDA may be useful as practical replacements of dairy products but cannot be considered nutritional replacements.

Diet-Derived Antioxidants and Their Role in Inflammation, Obesity and Gut Microbiota Modulation

It is generally accepted that gut microbiota, inflammation and obesity are linked to the development of cardiovascular diseases and other chronic/non-communicable pathological conditions, including cancer, neurodegenerative diseases and ageing-related disorders. In this scenario, oxidative stress plays a pivotal role. Evidence suggests that the global dietary patterns may represent a tool in counteracting oxidative stress, thus preventing the onset of diseases related to oxidative stress. More specifically, dietary patterns based on the regular consumption of fruits and vegetables (i.e., Mediterranean diet) have been licensed by various national nutritional guidelines in many countries for their health-promoting effects. Such patterns, indeed, result in being rich in specific components, such as fiber, minerals, vitamins and antioxidants, whose beneficial effects on human health have been widely reported. This suggests a potential nutraceutical power of specific dietary components. In this manuscript, we summarize the most relevant evidence reporting the impact of dietary antioxidants on gut microbiota composition, inflammation and obesity, and we underline that antioxidants are implicated in a complex interplay between gut microbiota, inflammation and obesity, thus suggesting their possible role in the development and modulation of chronic diseases related to oxidative stress and in the maintenance of wellness. Do all roads lead to Rome?

Macromineral and trace element concentrations and their seasonal variation in milk from organic and conventional dairy herds

To study the effects of dairy production system on milk macromineral and trace element concentrations, milk samples were collected monthly in 2019 from 43 conventional and 27 organic farms. Organic milk contained more Ca (1049.5 vs. 995.8 mg/kg), K (1383.6 vs. 1362.4 mg/kg), P (806.5 vs. 792.5 mg/kg) and Mo (73.3 vs. 60.6 μg/kg) but less Cu (52.4 vs. 60.6 μg/kg), Fe (0.66 vs 2.03 mg/kg), Mn (28.8 vs. 45.0 μg/kg), Zn (4.51 vs. 5.00 mg/kg) and Al (0.32 vs. 1.14 μg/kg) than conventional milk. Significant seasonal variation was observed in all determined minerals' concentrations. Milk I concentration was not consistently affected by production system, whereas organic milk contained less I in June and July than conventional milk. Dietary factors contributing to different milk mineral concentrations between production systems included intakes of maize silage, dry-straights and oils (higher in conventional diets), and pasture, clover and wholecrop (higher in organic diets).

A Survey of UK Centres on Low Iodine Diet Recommendations prior to Radioiodine Ablation Therapy for Differentiated Thyroid Cancer

BACKGROUND

Guidelines suggest that a low iodine diet (LID) is advised prior to radioiodine ablation (RIA) for thyroid cancer. We aim to describe current practice regarding LID advice in the UK, determine uptake of the 2016 UK LID Working Group diet sheet and discover whether there are differences in practice.

METHODS

We used an online survey distributed between November 2018 and April 2019 to centres in the UK that administer ¹³¹I. We asked questions on whether a LID is advised, for how long, how advice is presented, whether and how compliance is measured and whether treatment is delayed if LID advice is not followed.

RESULTS

Fifty-six clinicians from 47 centres that carry out RIA for thyroid cancer responded. Forty-four centres (94%) advise a LID prior to RIA, the majority for 14 days (82%). Two-thirds of the centres use the UK LID Working Group diet sheet. Patients are told to resume normal eating when ¹³¹I is administered at 17 centres (39%), with 18 (41%) advising waiting for 24-48 h after administration. Most centres (95%) use only a simple question or do not assess compliance. Only 2 (5%) indicate that RIA would be delayed if someone said they had not followed LID advice.

CONCLUSIONS

UK practice regarding LID prior to RIA for thyroid cancer is consistent with current guidelines, but non-adherence does not usually delay RIA. The UK Low Iodine Diet Working Group diet sheet is widely recognised and used. Practice could be improved by centres working to harmonise advice on when to restart a normal diet.

Micronutrients, iodine status and concentrations of thyroid hormones: a systematic review

Context

The metabolism of thyroid hormones, which are essential for normal development, involves many proteins and enzymes. It requires iodine as a key component but is also influenced by several other micronutrients, including selenium, zinc, iron, and vitamin A.

Objective

This systematic review was designed to investigate the effect of micronutrient status and supplementation on iodine status and thyroid hormone concentrations.

Data Sources

Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines, electronic databases were searched from their inception to April 2016.

Study Selection

Human studies published in English and reporting data on micronutrient status and iodine status and/or thyroid hormone concentrations were included. Studies that examined the effect of micronutrient supplementation on iodine status and/or thyroid hormone concentrations were also included.

Data Extraction

A predesigned and piloted data extraction form was used to compile data from individual studies.

Results

A total of 57 studies were included: 20 intervention studies and 37 observational studies. Although observational evidence suggests that concentrations of selenium, zinc, and iron are positively associated with iodine status, data from randomized controlled trials fail to confirm this relationship.

Conclusions

Further studies are needed to provide greater understanding of the role of micronutrient status in iodine nutrition and thyroid function to ascertain the public health implications for populations worldwide.

The effect of maternal iron deficiency on zinc and copper levels and on genes of zinc and copper metabolism during pregnancy in the rat

Fe deficiency is relatively common in pregnancy and has both short- and long-term consequences. However, little is known about the effect on the metabolism of other micronutrients. A total of fifty-four female rats were fed control (50 mg Fe/kg) or Fe-deficient diets (7·5 mg/kg) before and during pregnancy. Maternal liver, placenta and fetal liver were collected at day 21 of pregnancy for Cu and Zn analysis and to measure expression of the major genes of Cu and Zn metabolism. Cu levels increased in the maternal liver (P=0·002) and placenta (P=0·018) of Fe-deficient rats. Zn increased (P&lt;0·0001) and Cu decreased (P=0·006) in the fetal liver. Hepatic expression of the Cu chaperones antioxidant 1 Cu chaperone (P=0·042) and cytochrome c oxidase Cu chaperone (COX17, P=0·020) decreased in the Fe-deficient dams, while the expression of the genes of Zn metabolism was unaltered. In the placenta, Fe deficiency reduced the expression of the chaperone for superoxide dismutase 1, Cu chaperone for superoxide dismutase (P=0·030), ceruloplasmin (P=0·042) and Zn transport genes, ZRT/IRT-like protein 4 (ZIP4, P=0·047) and Zn transporter 1 (ZnT1, P=0·012). In fetal liver, Fe deficiency increased COX17 (P=0·020), ZRT/IRT-like protein 14 (P=0·036) and ZnT1 (P=0·0003) and decreased ZIP4 (P=0·004). The results demonstrate that Fe deficiency during pregnancy has opposite effects on Cu and Zn levels in the fetal liver. This may, in turn, alter metabolism of these nutrients, with consequences for development in the fetus and the neonate.

Micronutrient Intakes of British Adults Across Mid-Life: A Secondary Analysis of the UK National Diet and Nutrition Survey

Background: There is a tendency to report micronutrients intakes collectively for adults, with broad age ranges being used. This means that certain sub-population groups such as young adults are often overlooked. The objective of the present article was to derive and evaluate micronutrient intakes across UK adults in their twenties, thirties, forties and fifties. Methods: A secondary analysis of the UK National Diet and Nutrition Survey (years 1-6) was undertaken. Data from n = 3,238 adults was analyzed and micronutrient intakes from food sources (excluding supplements) derived as a percentage of the Reference Nutrient Intake (RNI) and percentage below the Lower Reference Nutrient Intake (LRNI) for males and females aged 20-29, 30-39, 40-49, and 50-59 years. Mean intakes were used in instances where this data was unavailable (for vitamins D and E). Results: Sizeable gaps were found for magnesium with 19% of young people in their twenties having intakes below the LRNI. Amongst UK females intakes of 9 micronutrients (riboflavin, vitamin B6, B12, folic acid, calcium, iron, magnesium, potassium, and iodine) were significantly lower than males aged 20-59 years (p < 0.001) expressed as a percentage of the RNI. Young adults in their twenties had significantly lower (p < 0.05) intakes of 8 micronutrients (vitamin A, riboflavin, folic acid, calcium, magnesium, potassium, iodine, and copper) expressed as a percentage of the RNI compared with adults in their thirties, forties and fifties. There were also considerable gaps in dietary selenium intakes with 50.3% females and 25.8% males having total intakes beneath the LRNI. A quarter of women had iron (25.3%) and potassium (24.3%) intakes below the LRNI. Conclusions: UK females and younger adults appear to be particularly vulnerable to micronutrient shortfalls from food sources alone. Clearly, improvements in dietary quality are needed across mid-life. Alongside this, fortification and supplementation strategies may be considered to help adults achieve dietary targets at this life-stage when they should be at their nutritional prime.

Nutrition in the Bin: A Nutritional and Environmental Assessment of Food Wasted in the UK

The UK currently has the most detailed, directly measured data for food wasted in the home. This includes information on the exact types of food wasted. These data allow calculation of the nutrients within that waste, as well as its environmental impact. The results progress the conversation beyond how much food is wasted or its energy content; it permits the implications for nutrition and sustainability to be assessed in detail. Data for UK household food waste were expressed as an average waste per capita for each type of food. Each food type was matched with an item (or group of items) from the UK Composition of Foods (7th Ed). The level of nutrients wasted was compared to UK Reference Nutrient Intakes (RNIs) for adult women (19–50 years, used as a proxy for general population requirements). The data were normalized into “nutrient days” wasted per capita per year, then into the number of complete diet days (for 21 nutrients plus energy). Results show that approximately 42 daily diets were discarded per capita per year. By individual nutrient, the highest losses were vitamin B₁₂, vitamin C, and thiamin (160, 140, and 130 nutrient days/capita/year, respectively). For protein, dietary energy and carbohydrates, 88, 59, and 53 nutrient days/capita/year, respectively, were lost. Substantial losses were also found for under-consumed nutrients in the UK: calcium, which was mostly lost via bakery (27%) and dairy/eggs (27%). Food folate was mainly lost through fresh vegetables/salads (40%) and bakery (18%), as was dietary fiber (31 and 29%, respectively). Environmental impacts were distributed over the food groups, with wasted meat and fish the single largest contribution. For all environmental impacts studied, the largest contribution came from agricultural production. This paper shows that there are areas where interventions preventing food waste and promoting healthy eating could work together (e.g., encouraging consumption of vegetables or tackling overbuying, especially of unhealthy foods). Food manufacturers and retailers, alongside governments and NGOs, have a key role to minimize waste of environmentally impactful, nutrient-dense foods, for instance, by helping influence people’s behaviors with appropriate formulation of products, packaging, portioning, use of promotions, or public education.

Further studies on the iodine concentration of conventional, organic and UHT semi-skimmed milk at retail in the UK

Milk is the largest source of iodine in UK diets and earlier studies showed organic summer and winter milk to be significantly lower in iodine than conventional milk. One study also showed UHT milk to have lower iodine concentration. The study on winter and UHT milk was small and accordingly a new study is reported here involving conventional, organic and UHT semi-skimmed milk from four supermarkets over a six-month period in summer and winter in two regions of the UK. The results showed organic milk to be 44% lower in iodine than conventional milk (427 vs. 241µg/L, P<0.001) and UHT milk was 27% lower in iodine than conventional milk (427 vs. 314µg/L, P<0.001) although the differences tended to be less in the summer. The results indicate that replacement of conventional milk by organic or UHT milk will increase the risk of sub-optimal iodine status especially for pregnant/lactating women.

Use of Linear Programming to Develop Cost-Minimized Nutritionally Adequate Health Promoting Food Baskets

Background

Food-Based Dietary Guidelines (FBDGs) are developed to promote healthier eating patterns, but increasing food prices may make healthy eating less affordable. The aim of this study was to design a range of cost-minimized nutritionally adequate health-promoting food baskets (FBs) that help prevent both micronutrient inadequacy and diet-related non-communicable diseases at lowest cost.

Methods

Average prices for 312 foods were collected within the Greater Copenhagen area. The cost and nutrient content of five different cost-minimized FBs for a family of four were calculated per day using linear programming. The FBs were defined using five different constraints: cultural acceptability (CA), or dietary guidelines (DG), or nutrient recommendations (N), or cultural acceptability and nutrient recommendations (CAN), or dietary guidelines and nutrient recommendations (DGN). The variety and number of foods in each of the resulting five baskets was increased through limiting the relative share of individual foods.

Results

The one-day version of N contained only 12 foods at the minimum cost of DKK 27 (€ 3.6). The CA, DG, and DGN were about twice of this and the CAN cost ~DKK 81 (€ 10.8). The baskets with the greater variety of foods contained from 70 (CAN) to 134 (DGN) foods and cost between DKK 60 (€ 8.1, N) and DKK 125 (€ 16.8, DGN). Ensuring that the food baskets cover both dietary guidelines and nutrient recommendations doubled the cost while cultural acceptability (CAN) tripled it.

Conclusion

Use of linear programming facilitates the generation of low-cost food baskets that are nutritionally adequate, health promoting, and culturally acceptable.