Micronutrient deficiencies, vitamin pills and nutritional supplements

In the 21st century, it is hard to reconcile the concepts of the Western diet and overconsumption with the risk of micronutrient deficiencies. However, deficiencies can arise from poor dietary intake, alone or combined with physiological or metabolic injury. Micronutrients are essential to fulfil a broad range of biochemical and physiological functions, and are tightly regulated by homeostatic processes. Diagnosis of deficiency is complex and requires the use of separate investigations (dietary, functional, biochemical). While the role of micronutrients in the prevention or treatment of diseases (including cancer, type 2 diabetes) is of interest, a key driver for the vitamins and supplement market is their advertised potential to optimize health and performance in healthy individuals. The evidence so far indicates that multivitamins supplements offer no health protection, increase all-cause mortality, and risk of cancers in some subgroups. A nutritionally balanced diet is a safer way to achieve sufficiency

The urinary phenolic acid profile varies between younger and older adults after a polyphenol-rich meal despite limited differences in in vitro colonic catabolism

Purpose: To investigate whether age influences colonic polyphenol metabolism. Methods: Healthy participants, younger (n = 8; 23–43 years) and older (n = 13; 51–76 years), followed a 3-day low-polyphenol diet (LPD) and a 3-day high-polyphenol diet (HPD). Urinary phenolic acids (PA), short chain fatty acids (SCFA), pH and gas were monitored, alongside selected colonic bacteria. Human faecal in vitro fermentations of rutin with or without raftiline were used to evaluate the gut microbiota capacity in a subset of both groups. Results: Total urinary PA were higher in the older group after HPD compared to the younger group (1.5-fold; p = 0.04), with no difference between groups in terms of a change between diets (Δ high-low diet). While 17 PA were detected in all younger participants after HPD, a narrower range (n = 8 to 16 PA) was detected in most (n = 9/13) older participants, with lower level of benzoic acid (19-fold; p = 0.03), vanillic acid (4.5-fold; p = 0.04) but higher hippuric acid (2.7-fold; p = 0.03). Faecal SCFA concentration did not change after HPD within group, with similar differential excretion (Δ high-low diet) between groups. There were no differences between groups for faecal pH, total, faecal bacteria including Flavonifractor plautii, bifidobacteria, and bacteroides. In human in vitro faecal fermentations, seven PAs were detected in both groups after 24 h of rutin fermentation, with no quantitative and modest qualitative differences between groups. Total SCFA in faecal fermentation did not differ between groups, except for butyric acid (twofold higher in the older group; p = 0.009) when rutin was fermented with raftiline over 24 h. Conclusions: Urinary phenolic acids were less diverse in older participants despite limited difference in functional capacity of in vitro faecal fermentations

Iodine and pregnancy – a qualitative study focusing on dietary guidance and information

Iodine is essential for thyroid hormones synthesis and normal neurodevelopment; however, ~60% of pregnant women do not meet the WHO (World Health Organization) recommended intake. Using a qualitative design, we explored the perceptions, awareness, and experiences of pregnancy nutrition, focusing on iodine. Women in the perinatal period (n = 48) were interviewed and filled in a food frequency questionnaire for iodine. Almost all participants achieved the recommended 150 μg/day intake for non-pregnant adults (99%), but only 81% met the increased demands of pregnancy (250 μg/day). Most were unaware of the importance, sources of iodine, and recommendations for iodine intake. Attitudes toward dairy products consumption were positive (e.g., helps with heartburn; easy to increase). Increased fish consumption was considered less achievable, with barriers around taste, smell, heartburn, and morning sickness. Community midwives were the main recognised provider of dietary advice. The dietary advice received focused most often on multivitamin supplements rather than food sources. Analysis highlighted a clear theme of commitment to change behaviour, motivated by pregnancy, with a desired focus on user-friendly documentation and continued involvement of the health services. The study highlights the importance of redirecting advice on dietary requirements in pregnancy and offers practical suggestions from women in the perinatal period as the main stakeholder group

'Language is the source of misunderstandings'–impact of terminology on public perceptions of health promotion messages

Background: The high level of premature death due to non-communicable diseases has been associated with unhealthful lifestyles, including poor diet. The effectiveness of public health strategies designed to promote health via messages focusing on food and diets depends largely on the perception of the messages by the public. The aim of this study was to explore public perceptions of language commonly used to communicate concepts linking health, food and the diet.<p></p> Methods: This study is a qualitative and semi-quantitative cross-sectional survey exploring public perceptions of terms used to improve eating habits within public health strategies. We recruited adults with no background in nutrition or health-care, from May to July 2013, from urban areas of varying deprivation (n = 12) in Glasgow and Edinburgh, UK. Four key prompt-terms used to convey the idea of improving health through diet were selected for testing: Healthy Eating, Eating for Health, Balanced Diet and Nutritional Balance. Consumer understanding of these terms was explored using mixed-methods, including qualitative focus groups (n = 17) and an interviewer-led word-association exercise (n = 270).<p></p> Results: The word-association exercise produced 1,386 individual responses from the four prompt-terms, with 130 unique responses associated with a single term. Cluster analysis revealed 16 key themes, with responses affected by prompt-term used, age, gender and socio-economic status. Healthy Eating was associated with foods considered ‘healthy’ (p <0.05); Eating for Health and Balanced Diet with negative connotations of foods to avoid (both p <0.001) and Nutritional Balance with the benefits of eating healthily (p <0.01). Focus groups revealed clear differences in perceptions: Eating for Health = positive action one takes to manage existing medical conditions, Healthy Eating = passive aspirational term associated with weight management, Balanced Diet = old fashioned, also dieting for weight loss, Nutritional Balance = maximising physical performance. Food suppliers use Healthy Eating terminology to promote weight management products. Focus group participants welcomed product reformulation to enhance food health properties as a strategy to overcome desensitisation to health-messages.<p></p> Conclusions: Public perceptions of messages communicating concepts linking health, food and the diet are influenced by terminology, resulting in confusion. To increase individual commitment to change eating habits in the long term, public health campaigns need strengthening, potentially by investing in tailored approaches to meet the needs of defined groups of consumers

Nutrient–nutrient interactions: competition, bioavailability, mechanism and function in health and diseases

The Nutrition Society Spring Conference 2018, held in Glasgow, brought together experts focusing on the interaction between different nutrients and how this impacts absorption, metabolism and health from biochemical and physiological perspectives. This cross-cutting theme was examined from a range of perspectives, bringing together experts on topics ranging from food processing to the impact of inflammation on nutrient status. Two plenary lectures provided a food landscape and lifecourse background to the proceedings, with on the first day a focus on processed/ultra-processed foods and their nutrient composition and, on the second day, a plenary lecture exploring the role that nutrient–nutrient interactions within the maternal diet have for the lifelong health of the offspring. The meeting was framed around three symposia, examining the competition and bioavailability of dietary components, nutrient–nutrient interactions and their role in protection from chronic diseases and the mechanisms of nutrient–nutrient interactions. The meeting ended with a round table, and an overall conclusion highlighting the opportunities to derive further understanding of the short- and long-term implications of diets through the study of nutrient–nutrient interactions

Emergence of seaweed and seaweed-containing foods in the UK: focus on labeling, iodine content, toxicity and nutrition

Seaweed (edible algae) is not a staple food in the Western diet, despite occasional use as a traditional ingredient in coastal areas. High nutritional value, combined with the expansion of the health-food industry, has led to a resurgence of seaweed in the British diet. While seaweed could be useful in tackling dietary iodine insufficiency, consumption of some species and sources of seaweed has also been associated with risks, such as toxicity from high iodine levels, or accumulation of arsenic, heavy metals and contaminants. The current retail level of seaweed and edible algae in the UK market, either as whole foods or ingredients, was evaluated with particular focus on labelling and iodine content. Seaweed-containing products (n = 224) were identified. Only 22 products (10%) stated information regarding iodine content and another 40 (18%) provided information sufficient to estimate the iodine content. For these products, the median iodine content was 110 μg/g (IQR 21–503) and 585 μg per estimated serving (IQR 105–2520). While calculations for iodine exposure per serving relied on assumptions, 26 products could potentially lead to an iodine intake above the (European) tolerable adult upper level of 600 μg/day. In the context of the data presented, there is scope to improve product labelling (species, source, processing, content)

Determination of the chemical composition of tea by chromatographic methods: a review

Despite the fact that mankind has been drinking tea for more than 5000 years, its chemical composition has been studied only in recent decades. These studies are primarily carried out using chromatographic methods. This review summarizes the latest information regarding the chemical composition of different tea grades by different chromatographic methods, which has not previously been reviewed in the same scope. Over the last 40 years, the qualitative and quantitative analyses of high volatile compounds were determined by GC and GC/MS. The main components responsible for aroma of green and black tea were revealed, and the low volatile compounds basically were determined by HPLC and LC/MS methods. Most studies focusing on the determination of catechins and caffeine in various teas (green, oolong, black and pu-erh) involved HPLC analysis. Knowledge of tea chemical composition helps in assessing its quality on the one hand, and helps to monitor and manage its growing, processing, and storage conditions on the other. In particular, this knowledge has enabled to establish the relationships between the chemical composition of tea and its properties by identifying the tea constituents which determine its aroma and taste. Therefore, assessment of tea quality does not only rely on subjective organoleptic evaluation, but also on objective physical and chemical methods, with extra determination of tea components most beneficial to human health. With this knowledge, the nutritional value of tea may be increased, and tea quality improved by providing via optimization of the growing, processing, and storage conditions.</p

Lower carbohydrate and higher fat intakes are associated with higher hemoglobin A1c: findings from the UK National Diet and Nutrition Survey 2008-2016

Purpose: Evidence of low-carbohydrate, high-fat diets (LCHF) for type 2 diabetes (T2DM) prevention is scarce. We investigated how carbohydrate intake relates to HbA1c and T2DM prevalence in a nationally representative survey dataset. Methods: We analyzed dietary information (4-day food diaries) from 3234 individuals aged ≥ 16 years, in eight waves of the UK National Diet and Nutrition Survey (2008–2016). We calculated LCHF scores (0–20, higher score indicating lower %food energy from carbohydrate, with reciprocal higher contribution from fat) and UK Dietary Reference Value (DRV) scores (0–16, based on UK dietary recommendations). Associations between macronutrients and diet scores and diabetes prevalence were analyzed (in the whole sample) using multivariate logistic regression. Among those without diabetes, analyses between exposures and %HbA1c (continuous) were analyzed using multivariate linear regression. All analyses were adjusted for age, sex, body mass index, ethnicity, smoking status, total energy intake, socioeconomic status and survey years. Results: In the overall study sample, 194 (6.0%) had diabetes. Mean intake was 48.0%E for carbohydrates, and 34.9%E for total fat. Every 5%E decrease in carbohydrate, and every 5%E increase in fat, was associated with 12% (95% CI 0.78–0.99; P = 0.03) and 17% (95% CI 1.02–1.33; P = 0.02) higher odds of diabetes, respectively. Each two-point increase in LCHF score is related to 8% (95% CI 1.02–1.14; P = 0.006) higher odds of diabetes, while there was no evidence for association between DRV score and diabetes. Among the participants without diagnosed diabetes (n = 3130), every 5%E decrease in carbohydrate was associated with higher %HbA1c by + 0.016% (95% CI 0.004–0.029; P = 0.012), whereas every 5%E increase in fat was associated with higher %HbA1c by + 0.029% (95% CI 0.015–0.043; P &lt; 0.001). Each two-point increase in LCHF score is related to higher %HbA1c by + 0.010% (0.1 mmol/mol), while each two-point increase in the DRV score is related to lower %HbA1c by − 0.023% (0.23 mmol/mol). Conclusions: Lower carbohydrate and higher fat intakes were associated with higher HbA1c and greater odds of having diabetes. These data do not support low(er) carbohydrate diets for diabetes prevention

Carbohydrate knowledge, dietary guideline awareness, motivations and beliefs underlying low-carbohydrate dietary behaviours

To explore the factors (including knowledge and attitude) influencing the decision to follow a low-carbohydrate diet (LCD) or not in a sample of the UK population. An online questionnaire was distributed electronically to adults who had either followed LCD or not (February–December 2019). Demographics and self-reported “LCD-status” (current, past and non-follower) were collected. Multivariable linear regression was used with carbohydrate knowledge, dietary guideline agreement and theory of planned behaviour (TPB) constructs (all as predictors) to explain the intention to follow a LCD (outcome). Respondents (n = 723, 71% women, median age 34; 85% white-ethnicity) were either following (n = 170, 24%) or had tried a LCD in the preceding 3 months (n = 184, 25%). Current followers had lower carbohydrate knowledge scores (1–2 point difference, scale − 11 to 11) than past and non-followers. A majority of current LCD followers disagreed with the EatWell guide recommendations “Base meals on potatoes, bread, rice and pasta, or other starchy carbohydrates. Choose whole grains where possible” (84%) and “Choose unsaturated oils and spreads and eat in small amounts such as vegetable, rapeseed, olive and sunflower oils” (68%) compared to past (37%, 10%, respectively) and non-followers (16%, 8%, respectively). Weight-loss ranked first as a motivation, and the internet was the most influencial source of information about LCDs. Among LCD-followers, 71% reported ≥ 5% weight loss, and over 80% did not inform their doctor, nurse, or dietitian about following a diet. Approximately half of LCD followers incorporated supplements to their diets (10% used multivitamin/mineral supplements), despite the restrictive nature of the diet. TPB constructs, carbohydrate knowledge, and guideline agreement explained 60% of the variance for the intention to follow a LCD. Attitude (std-β = 0.60), perceived behavioural control (std-β = 0.24) and subjective norm (std-β = 0.14) were positively associated with the intention to follow a LCD, while higher knowledge of carbohydrate, and agreeing with national dietary guidelines were both inversely associated (std-β = − 0.09 and − 0.13). The strongest primary reason behind UK adults’ following a LCD is to lose weight, facilitated by attitude, perceived behavioural control and subjective norm. Higher knowledge about carbohydrate and agreement with dietary guidelines are found among people who do not follow LCDs

Low-level seaweed supplementation improves iodine status in iodine-insufficient women

Iodine insufficiency is now a prominent issue in the UK and other European countries due to low intakes of dairy products and seafood (especially where iodine fortification is not in place). In the present study, we tested a commercially available encapsulated edible seaweed (Napiers Hebridean Seagreens® Ascophyllum nodosumspecies) for its acceptability to consumers and iodine bioavailability and investigated the impact of a 2-week daily seaweed supplementation on iodine concentrations and thyroid function. Healthy non-pregnant women of childbearing age, self-reporting low dairy product and seafood consumption, with no history of thyroid or gastrointestinal disease were recruited. Seaweed iodine (712 μg, in 1 g seaweed) was modestly bioavailable at 33 (interquartile range (IQR) 28–46) % of the ingested iodine dose compared with 59 (IQR 46–74) % of iodine from the KI supplement (n 22). After supplement ingestion (2 weeks, 0•5 g seaweed daily, &lt;i&gt;n&lt;/i&gt; 42), urinary iodine excretion increased from 78 (IQR 39–114) to 140 (IQR 103–195) μg/l (&lt;i&gt;P&lt;/i&gt;&lt; 0•001). The concentrations of thyroid-stimulating hormone increased from 1•5 (IQR 1•2–2•2) to 2•1 (IQR 1•3–2•9) mIU/l (&lt;i&gt;P&lt;/i&gt;&lt; 0•001), with two participants having concentrations exceeding the normal range after supplement ingestion (but normal free thyroxine concentrations). There was no change in the concentrations of other thyroid hormones after supplement ingestion. The seaweed was palatable and acceptable to consumers as a whole food or as a food ingredient and effective as a source of iodine in an iodine-insufficient population. In conclusion, seaweed inclusion in staple foods would serve as an alternative to fortification of salt or other foods with KI